/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.tools.ant;

import java.io.File;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import org.apache.tools.ant.taskdefs.PreSetDef;
import org.apache.tools.ant.types.EnumeratedAttribute;
import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.types.resources.FileProvider;
import org.apache.tools.ant.types.resources.FileResource;
import org.apache.tools.ant.util.StringUtils;

Helper class that collects the methods a task or nested element holds to set attributes, create nested elements or hold PCDATA elements. It contains hashtables containing classes that use introspection to handle all the invocation of the project-component specific methods. This class is somewhat complex, as it implements the O/X mapping between Ant XML and Java class instances. This is not the best place for someone new to Ant to start contributing to the codebase, as a change here can break the entire system in interesting ways. Always run a full test of Ant before checking in/submitting changes to this file. The class is final and has a private constructor. To get an instance for a specific (class,project) combination, use getHelper(Project, Class<?>). This may return an existing version, or a new one ...do not make any assumptions about its uniqueness, or its validity after the Project instance has finished its build. /**
 * Helper class that collects the methods a task or nested element
 * holds to set attributes, create nested elements or hold PCDATA
 * elements.
 *
 * It contains hashtables containing classes that use introspection
 * to handle all the invocation of the project-component specific methods.
 *
 * This class is somewhat complex, as it implements the O/X mapping between
 * Ant XML and Java class instances. This is not the best place for someone new
 * to Ant to start contributing to the codebase, as a change here can break the
 * entire system in interesting ways. Always run a full test of Ant before checking
 * in/submitting changes to this file.
 *
 * The class is final and has a private constructor.
 * To get an instance for a specific (class,project) combination,
 * use {@link #getHelper(Project,Class)}.
 * This may return an existing version, or a new one
 * ...do not make any assumptions about its uniqueness, or its validity after the Project
 * instance has finished its build.
 *
 */
public final class IntrospectionHelper {

    
Helper instances we've already created (Class.getName() to IntrospectionHelper).
/**
     * Helper instances we've already created (Class.getName() to IntrospectionHelper).
     */
    private static final Map<String, IntrospectionHelper> HELPERS = new Hashtable<>();

    
Map from primitive types to wrapper classes for use in
createAttributeSetter (Class to Class). Note that char
and boolean are in here even though they get special treatment
- this way we only need to test for the wrapper class.
/**
     * Map from primitive types to wrapper classes for use in
     * createAttributeSetter (Class to Class). Note that char
     * and boolean are in here even though they get special treatment
     * - this way we only need to test for the wrapper class.
     */
    private static final Map<Class<?>, Class<?>> PRIMITIVE_TYPE_MAP = new HashMap<>(8);

    // Set up PRIMITIVE_TYPE_MAP
    static {
        final Class<?>[] primitives = {Boolean.TYPE, Byte.TYPE, Character.TYPE, Short.TYPE,
                              Integer.TYPE, Long.TYPE, Float.TYPE, Double.TYPE};
        final Class<?>[] wrappers = {Boolean.class, Byte.class, Character.class, Short.class,
                            Integer.class, Long.class, Float.class, Double.class};
        for (int i = 0; i < primitives.length; i++) {
            PRIMITIVE_TYPE_MAP.put(primitives[i], wrappers[i]);
        }
    }

    private static final int MAX_REPORT_NESTED_TEXT = 20;
    private static final String ELLIPSIS = "...";

    
Map from attribute names to attribute types
(String to Class).
/**
     * Map from attribute names to attribute types
     * (String to Class).
     */
    private final Map<String, Class<?>> attributeTypes = new Hashtable<>();

    
Map from attribute names to attribute setter methods
(String to AttributeSetter).
/**
     * Map from attribute names to attribute setter methods
     * (String to AttributeSetter).
     */
    private final Map<String, AttributeSetter> attributeSetters = new Hashtable<>();

    
Map from attribute names to nested types
(String to Class).
/**
     * Map from attribute names to nested types
     * (String to Class).
     */
    private final Map<String, Class<?>> nestedTypes = new Hashtable<>();

    
Map from attribute names to methods to create nested types
(String to NestedCreator).
/**
     * Map from attribute names to methods to create nested types
     * (String to NestedCreator).
     */
    private final Map<String, NestedCreator> nestedCreators = new Hashtable<>();

    
Vector of methods matching add[Configured](Class) pattern.
/**
     * Vector of methods matching add[Configured](Class) pattern.
     */
    private final List<Method> addTypeMethods = new ArrayList<>();

    
The method to invoke to add PCDATA.
/**
     * The method to invoke to add PCDATA.
     */
    private final Method addText;

    
The class introspected by this instance.
/**
     * The class introspected by this instance.
     */
    private final Class<?> bean;

    
Sole constructor, which is private to ensure that all IntrospectionHelpers are created via getHelper. Introspects the given class for bean-like methods. Each method is examined in turn, and the following rules are applied: 


If the method is Task.setLocation(Location),
Task.setTaskType(String)
or TaskContainer.addTask(Task), it is ignored. These
methods are handled differently elsewhere.
void addText(String) is recognised as the method for
adding PCDATA to a bean.
void setFoo(Bar) is recognised as a method for
setting the value of attribute foo, so long as
Bar is non-void and is not an array type.
As of Ant 1.8, a Resource or FileProvider parameter overrides a java.io.File parameter;
in practice the only effect of this is to allow objects rendered from
the 1.8 PropertyHelper implementation to be used as Resource parameters,
since Resources set from Strings are resolved as project-relative files
to preserve backward compatibility.  Beyond this, non-String
parameter types always overload String parameter types; these are
the only guarantees made in terms of priority.
Foo createBar() is recognised as a method for
creating a nested element called bar of type
Foo, so long as Foo is not a primitive or
array type.
void addConfiguredFoo(Bar) is recognised as a
method for storing a pre-configured element called
foo and of type Bar, so long as
Bar is not an array, primitive or String type.
Bar must have an accessible constructor taking no
arguments.
void addFoo(Bar) is recognised as a method for storing
an element called foo and of type Bar, so
long as Bar is not an array, primitive or String type.
Bar must have an accessible constructor taking no
arguments. This is distinct from the 'addConfigured' idiom in that
the nested element is added to the parent immediately after it is
constructed; in practice this means that addFoo(Bar) should
do little or nothing with its argument besides storing it for later use.

Note that only one method is retained to create/set/addConfigured/add
any element or attribute.
Params:
bean – The bean type to introspect.
            Must not be null.
See Also:
getHelper(Class<?>)/**
     * Sole constructor, which is private to ensure that all
     * IntrospectionHelpers are created via {@link #getHelper(Class) getHelper}.
     * Introspects the given class for bean-like methods.
     * Each method is examined in turn, and the following rules are applied:
     * <p>
     * <ul>
     * <li>If the method is <code>Task.setLocation(Location)</code>,
     * <code>Task.setTaskType(String)</code>
     * or <code>TaskContainer.addTask(Task)</code>, it is ignored. These
     * methods are handled differently elsewhere.
     * <li><code>void addText(String)</code> is recognised as the method for
     * adding PCDATA to a bean.
     * <li><code>void setFoo(Bar)</code> is recognised as a method for
     * setting the value of attribute <code>foo</code>, so long as
     * <code>Bar</code> is non-void and is not an array type.
     * As of Ant 1.8, a Resource or FileProvider parameter overrides a java.io.File parameter;
     * in practice the only effect of this is to allow objects rendered from
     * the 1.8 PropertyHelper implementation to be used as Resource parameters,
     * since Resources set from Strings are resolved as project-relative files
     * to preserve backward compatibility.  Beyond this, non-String
     * parameter types always overload String parameter types; these are
     * the only guarantees made in terms of priority.
     * <li><code>Foo createBar()</code> is recognised as a method for
     * creating a nested element called <code>bar</code> of type
     * <code>Foo</code>, so long as <code>Foo</code> is not a primitive or
     * array type.
     * <li><code>void addConfiguredFoo(Bar)</code> is recognised as a
     * method for storing a pre-configured element called
     * <code>foo</code> and of type <code>Bar</code>, so long as
     * <code>Bar</code> is not an array, primitive or String type.
     * <code>Bar</code> must have an accessible constructor taking no
     * arguments.
     * <li><code>void addFoo(Bar)</code> is recognised as a method for storing
     * an element called <code>foo</code> and of type <code>Bar</code>, so
     * long as <code>Bar</code> is not an array, primitive or String type.
     * <code>Bar</code> must have an accessible constructor taking no
     * arguments. This is distinct from the 'addConfigured' idiom in that
     * the nested element is added to the parent immediately after it is
     * constructed; in practice this means that <code>addFoo(Bar)</code> should
     * do little or nothing with its argument besides storing it for later use.
     * </ul>
     * Note that only one method is retained to create/set/addConfigured/add
     * any element or attribute.
     *
     * @param bean The bean type to introspect.
     *             Must not be <code>null</code>.
     *
     * @see #getHelper(Class)
     */
    private IntrospectionHelper(final Class<?> bean) {
        this.bean = bean;
        Method addTextMethod = null;
        for (final Method m : bean.getMethods()) {
            final String name = m.getName();
            final Class<?> returnType = m.getReturnType();
            final Class<?>[] args = m.getParameterTypes();

            // check of add[Configured](Class) pattern
            if (args.length == 1 && Void.TYPE.equals(returnType)
                    && ("add".equals(name) || "addConfigured".equals(name))) {
                insertAddTypeMethod(m);
                continue;
            }
            // not really user settable properties on tasks/project components
            if (ProjectComponent.class.isAssignableFrom(bean)
                    && args.length == 1 && isHiddenSetMethod(name, args[0])) {
                continue;
            }
            // hide addTask for TaskContainers
            if (isContainer() && args.length == 1 && "addTask".equals(name)
                    && Task.class.equals(args[0])) {
                continue;
            }
            if ("addText".equals(name) && Void.TYPE.equals(returnType)
                    && args.length == 1 && String.class.equals(args[0])) {
                addTextMethod = m;
            } else if (name.startsWith("set") && Void.TYPE.equals(returnType)
                    && args.length == 1 && !args[0].isArray()) {
                final String propName = getPropertyName(name, "set");
                AttributeSetter as = attributeSetters.get(propName);
                if (as != null) {
                    if (String.class.equals(args[0])) {
                        /*
                            Ignore method m, as there is an overloaded
                            form of this method that takes in a
                            non-string argument, which gains higher
                            priority.
                        */
                        continue;
                    }
                    if (File.class.equals(args[0])) {
                        // Ant Resources/FileProviders override java.io.File
                        if (Resource.class.equals(as.type) || FileProvider.class.equals(as.type)) {
                            continue;
                        }
                    }
                    /*
                        In cases other than those just explicitly covered,
                        we just override that with the new one.
                        This mechanism does not guarantee any specific order
                        in which the methods will be selected: so any code
                        that depends on the order in which "set" methods have
                        been defined, is not guaranteed to be selected in any
                        particular order.
                    */
                }
                as = createAttributeSetter(m, args[0], propName);
                if (as != null) {
                    attributeTypes.put(propName, args[0]);
                    attributeSetters.put(propName, as);
                }
            } else if (name.startsWith("create") && !returnType.isArray()
                    && !returnType.isPrimitive() && args.length == 0) {

                final String propName = getPropertyName(name, "create");
                // Check if a create of this property is already present
                // add takes preference over create for CB purposes
                if (nestedCreators.get(propName) == null) {
                    nestedTypes.put(propName, returnType);
                    nestedCreators.put(propName, new CreateNestedCreator(m));
                }
            } else if (name.startsWith("addConfigured")
                    && Void.TYPE.equals(returnType) && args.length == 1
                    && !String.class.equals(args[0])
                    && !args[0].isArray() && !args[0].isPrimitive()) {
                try {
                    Constructor<?> constructor = null;
                    try {
                        constructor = args[0].getConstructor();
                    } catch (final NoSuchMethodException ex) {
                        constructor = args[0].getConstructor(Project.class);
                    }
                    final String propName = getPropertyName(name, "addConfigured");
                    nestedTypes.put(propName, args[0]);
                    nestedCreators.put(propName, new AddNestedCreator(m,
                        constructor, AddNestedCreator.ADD_CONFIGURED));
                } catch (final NoSuchMethodException nse) {
                    // ignore
                }
            } else if (name.startsWith("add")
                    && Void.TYPE.equals(returnType) && args.length == 1
                    && !String.class.equals(args[0])
                    && !args[0].isArray() && !args[0].isPrimitive()) {
                try {
                    Constructor<?> constructor = null;
                    try {
                        constructor = args[0].getConstructor();
                    } catch (final NoSuchMethodException ex) {
                        constructor = args[0].getConstructor(Project.class);
                    }
                    final String propName = getPropertyName(name, "add");
                    if (nestedTypes.get(propName) != null) {
                        /*
                         *  Ignore this method as there is an addConfigured
                         *  form of this method that has a higher
                         *  priority
                         */
                        continue;
                    }
                    nestedTypes.put(propName, args[0]);
                    nestedCreators.put(propName, new AddNestedCreator(m,
                            constructor, AddNestedCreator.ADD));
                } catch (final NoSuchMethodException nse) {
                    // ignore
                }
            }
        }
        addText = addTextMethod;
    }

    
Certain set methods are part of the Ant core interface to tasks and
therefore not to be considered for introspection
Params:
name – the name of the set method
type – the type of the set method's parameter
Returns:
true if the given set method is to be hidden./**
     * Certain set methods are part of the Ant core interface to tasks and
     * therefore not to be considered for introspection
     *
     * @param name the name of the set method
     * @param type the type of the set method's parameter
     * @return true if the given set method is to be hidden.
     */
    private boolean isHiddenSetMethod(final String name, final Class<?> type) {
        return "setLocation".equals(name) && Location.class.equals(type)
                || "setTaskType".equals(name) && String.class.equals(type);
    }

    
Returns a helper for the given class, either from the cache
or by creating a new instance.
Params:
c – The class for which a helper is required.
         Must not be null.
Returns:
a helper for the specified class/**
     * Returns a helper for the given class, either from the cache
     * or by creating a new instance.
     *
     * @param c The class for which a helper is required.
     *          Must not be <code>null</code>.
     *
     * @return a helper for the specified class
     */
    public static synchronized IntrospectionHelper getHelper(final Class<?> c) {
        return getHelper(null, c);
    }

    
Returns a helper for the given class, either from the cache
or by creating a new instance.
The method will make sure the helper will be cleaned up at the end of
the project, and only one instance will be created for each class.
Params:
p – the project instance. Can be null, in which case the helper is not cached.
c – The class for which a helper is required.
         Must not be null.
Returns:
a helper for the specified class/**
     * Returns a helper for the given class, either from the cache
     * or by creating a new instance.
     *
     * The method will make sure the helper will be cleaned up at the end of
     * the project, and only one instance will be created for each class.
     *
     * @param p the project instance. Can be null, in which case the helper is not cached.
     * @param c The class for which a helper is required.
     *          Must not be <code>null</code>.
     *
     * @return a helper for the specified class
     */
    public static synchronized IntrospectionHelper getHelper(final Project p, final Class<?> c) {
        IntrospectionHelper ih = HELPERS.get(c.getName());
        // If a helper cannot be found, or if the helper is for another
        // classloader, create a new IH
        if (ih == null || ih.bean != c) {
            ih = new IntrospectionHelper(c);
            if (p != null) {
                // #30162: do *not* cache this if there is no project, as we
                // cannot guarantee that the cache will be cleared.
                HELPERS.put(c.getName(), ih);
            }
        }
        return ih;
    }

    
Sets the named attribute in the given element, which is part of the
given project.
Params:
p – The project containing the element. This is used when files
         need to be resolved. Must not be null.
element – The element to set the attribute in. Must not be
               null.
attributeName – The name of the attribute to set. Must not be
                     null.
value – The value to set the attribute to. This may be interpreted
             or converted to the necessary type if the setter method
             doesn't accept an object of the supplied type.
Throws:
BuildException – if the introspected class doesn't support
                          the given attribute, or if the setting
                          method fails./**
     * Sets the named attribute in the given element, which is part of the
     * given project.
     *
     * @param p The project containing the element. This is used when files
     *          need to be resolved. Must not be <code>null</code>.
     * @param element The element to set the attribute in. Must not be
     *                <code>null</code>.
     * @param attributeName The name of the attribute to set. Must not be
     *                      <code>null</code>.
     * @param value The value to set the attribute to. This may be interpreted
     *              or converted to the necessary type if the setter method
     *              doesn't accept an object of the supplied type.
     *
     * @exception BuildException if the introspected class doesn't support
     *                           the given attribute, or if the setting
     *                           method fails.
     */
    public void setAttribute(final Project p, final Object element, final String attributeName,
            final Object value) throws BuildException {
        final AttributeSetter as = attributeSetters.get(
                attributeName.toLowerCase(Locale.ENGLISH));
        if (as == null && value != null) {
            if (element instanceof DynamicAttributeNS) {
                final DynamicAttributeNS dc = (DynamicAttributeNS) element;
                final String uriPlusPrefix = ProjectHelper.extractUriFromComponentName(attributeName);
                final String uri = ProjectHelper.extractUriFromComponentName(uriPlusPrefix);
                final String localName = ProjectHelper.extractNameFromComponentName(attributeName);
                final String qName = uri.isEmpty() ? localName : uri + ":" + localName;
                dc.setDynamicAttribute(uri, localName, qName, value.toString());
                return;
            }
            if (element instanceof DynamicObjectAttribute) {
                final DynamicObjectAttribute dc = (DynamicObjectAttribute) element;
                dc.setDynamicAttribute(attributeName.toLowerCase(Locale.ENGLISH), value);
                return;
            }
            if (element instanceof DynamicAttribute) {
                final DynamicAttribute dc = (DynamicAttribute) element;
                dc.setDynamicAttribute(attributeName.toLowerCase(Locale.ENGLISH), value.toString());
                return;
            }
            if (attributeName.contains(":")) {
                return; // Ignore attribute from unknown uri's
            }
            final String msg = getElementName(p, element)
                    + " doesn't support the \"" + attributeName + "\" attribute.";
            throw new UnsupportedAttributeException(msg, attributeName);
        }
        if (as != null) { // possible if value == null
            try {
                as.setObject(p, element, value);
            } catch (final IllegalAccessException ie) {
                // impossible as getMethods should only return public methods
                throw new BuildException(ie);
            } catch (final InvocationTargetException ite) {
                throw extractBuildException(ite);
            }
        }
    }

    
Sets the named attribute in the given element, which is part of the
given project.
Params:
p – The project containing the element. This is used when files
         need to be resolved. Must not be null.
element – The element to set the attribute in. Must not be
               null.
attributeName – The name of the attribute to set. Must not be
                     null.
value – The value to set the attribute to. This may be interpreted
             or converted to the necessary type if the setter method
             doesn't just take a string. Must not be null.
Throws:
BuildException – if the introspected class doesn't support
                          the given attribute, or if the setting
                          method fails./**
     * Sets the named attribute in the given element, which is part of the
     * given project.
     *
     * @param p The project containing the element. This is used when files
     *          need to be resolved. Must not be <code>null</code>.
     * @param element The element to set the attribute in. Must not be
     *                <code>null</code>.
     * @param attributeName The name of the attribute to set. Must not be
     *                      <code>null</code>.
     * @param value The value to set the attribute to. This may be interpreted
     *              or converted to the necessary type if the setter method
     *              doesn't just take a string. Must not be <code>null</code>.
     *
     * @exception BuildException if the introspected class doesn't support
     *                           the given attribute, or if the setting
     *                           method fails.
     */
    public void setAttribute(final Project p, final Object element, final String attributeName,
                             final String value) throws BuildException {
        setAttribute(p, element, attributeName, (Object) value);
    }

    
Adds PCDATA to an element, using the element's
void addText(String) method, if it has one. If no
such method is present, a BuildException is thrown if the
given text contains non-whitespace.
Params:
project – The project which the element is part of.
               Must not be null.
element – The element to add the text to.
               Must not be null.
text –    The text to add.
               Must not be null.
Throws:
BuildException – if non-whitespace text is provided and no
                          method is available to handle it, or if
                          the handling method fails./**
     * Adds PCDATA to an element, using the element's
     * <code>void addText(String)</code> method, if it has one. If no
     * such method is present, a BuildException is thrown if the
     * given text contains non-whitespace.
     *
     * @param project The project which the element is part of.
     *                Must not be <code>null</code>.
     * @param element The element to add the text to.
     *                Must not be <code>null</code>.
     * @param text    The text to add.
     *                Must not be <code>null</code>.
     *
     * @exception BuildException if non-whitespace text is provided and no
     *                           method is available to handle it, or if
     *                           the handling method fails.
     */
    public void addText(final Project project, final Object element, String text)
        throws BuildException {
        if (addText == null) {
            text = text.trim();
            // Element doesn't handle text content
            if (text.isEmpty()) {
                // Only whitespace - ignore
                return;
            }
            // Not whitespace - fail
            throw new BuildException(project.getElementName(element)
                    + " doesn't support nested text data (\"" + condenseText(text) + "\").");
        }
        try {
            addText.invoke(element, text);
        } catch (final IllegalAccessException ie) {
            // impossible as getMethods should only return public methods
            throw new BuildException(ie);
        } catch (final InvocationTargetException ite) {
            throw extractBuildException(ite);
        }
    }

    
part of the error message created by 
throwNotSupported. 
Since:
Ant 1.8.0/**
     * part of the error message created by {@link #throwNotSupported
     * throwNotSupported}.
     * @since Ant 1.8.0
     */
    protected static final String NOT_SUPPORTED_CHILD_PREFIX =
        " doesn't support the nested \"";

    
part of the error message created by 
throwNotSupported. 
Since:
Ant 1.8.0/**
     * part of the error message created by {@link #throwNotSupported
     * throwNotSupported}.
     * @since Ant 1.8.0
     */
    protected static final String NOT_SUPPORTED_CHILD_POSTFIX = "\" element.";

    
Utility method to throw a NotSupported exception
Params:
project – the Project instance.
parent – the object which doesn't support a requested element
elementName – the name of the Element which is trying to be created./**
     * Utility method to throw a NotSupported exception
     *
     * @param project the Project instance.
     * @param parent the object which doesn't support a requested element
     * @param elementName the name of the Element which is trying to be created.
     */
    public void throwNotSupported(final Project project, final Object parent, final String elementName) {
        final String msg = project.getElementName(parent)
            + NOT_SUPPORTED_CHILD_PREFIX + elementName
            + NOT_SUPPORTED_CHILD_POSTFIX;
        throw new UnsupportedElementException(msg, elementName);
    }

    
Get the specific NestedCreator for a given project/parent/element combination
Params:
project – ant project
parentUri – URI of the parent.
parent – the parent class
elementName – element to work with. This can contain
 a URI,localname tuple of of the form uri:localname
child – the bit of XML to work with
Throws:
BuildException – if the parent does not support child elements of that name
Returns:
a nested creator that can handle the child elements./**
     * Get the specific NestedCreator for a given project/parent/element combination
     * @param project ant project
     * @param parentUri URI of the parent.
     * @param parent the parent class
     * @param elementName element to work with. This can contain
     *  a URI,localname tuple of of the form uri:localname
     * @param child the bit of XML to work with
     * @return a nested creator that can handle the child elements.
     * @throws BuildException if the parent does not support child elements of that name
     */
    private NestedCreator getNestedCreator(
        final Project project, String parentUri, final Object parent,
        final String elementName, final UnknownElement child) throws BuildException {

        String uri = ProjectHelper.extractUriFromComponentName(elementName);
        final String name = ProjectHelper.extractNameFromComponentName(elementName);

        if (uri.equals(ProjectHelper.ANT_CORE_URI)) {
            uri = "";
        }
        if (parentUri.equals(ProjectHelper.ANT_CORE_URI)) {
            parentUri = "";
        }
        NestedCreator nc = null;
        if (uri.equals(parentUri) || uri.isEmpty()) {
            nc = nestedCreators.get(name.toLowerCase(Locale.ENGLISH));
        }
        if (nc == null) {
            nc = createAddTypeCreator(project, parent, elementName);
        }
        if (nc == null
                && (parent instanceof DynamicElementNS || parent instanceof DynamicElement)) {
            final String qName = child == null ? name : child.getQName();
            final Object nestedElement = createDynamicElement(parent,
                    child == null ? "" : child.getNamespace(), name, qName);
            if (nestedElement != null) {
                nc = new NestedCreator(null) {
                    @Override
                    Object create(final Project project, final Object parent, final Object ignore) {
                        return nestedElement;
                    }
                };
            }
        }
        if (nc == null) {
            throwNotSupported(project, parent, elementName);
        }
        return nc;
    }

    
Invokes the "correct" createDynamicElement method on parent in
order to obtain a child element by name.
Since:
Ant 1.8.0./**
     * Invokes the "correct" createDynamicElement method on parent in
     * order to obtain a child element by name.
     *
     * @since Ant 1.8.0.
     */
    private Object createDynamicElement(final Object parent, final String ns,
                                        final String localName, final String qName) {
        Object nestedElement = null;
        if (parent instanceof DynamicElementNS) {
            final DynamicElementNS dc = (DynamicElementNS) parent;
            nestedElement = dc.createDynamicElement(ns, localName, qName);
        }
        if (nestedElement == null && parent instanceof DynamicElement) {
            final DynamicElement dc = (DynamicElement) parent;
            nestedElement =
                dc.createDynamicElement(localName.toLowerCase(Locale.ENGLISH));
        }
        return nestedElement;
    }

    
Creates a named nested element. Depending on the results of the
initial introspection, either a method in the given parent instance
or a simple no-arg constructor is used to create an instance of the
specified element type.
Params:
project – Project to which the parent object belongs.
               Must not be null. If the resulting
               object is an instance of ProjectComponent, its
               Project reference is set to this parameter value.
parent –  Parent object used to create the instance.
               Must not be null.
elementName – Name of the element to create an instance of.
                   Must not be null.
Throws:
BuildException – if no method is available to create the
                          element instance, or if the creating method fails.
Returns:
an instance of the specified element type
Deprecated:
since 1.6.x.
            This is not a namespace aware method./**
     * Creates a named nested element. Depending on the results of the
     * initial introspection, either a method in the given parent instance
     * or a simple no-arg constructor is used to create an instance of the
     * specified element type.
     *
     * @param project Project to which the parent object belongs.
     *                Must not be <code>null</code>. If the resulting
     *                object is an instance of ProjectComponent, its
     *                Project reference is set to this parameter value.
     * @param parent  Parent object used to create the instance.
     *                Must not be <code>null</code>.
     * @param elementName Name of the element to create an instance of.
     *                    Must not be <code>null</code>.
     *
     * @return an instance of the specified element type
     * @deprecated since 1.6.x.
     *             This is not a namespace aware method.
     *
     * @exception BuildException if no method is available to create the
     *                           element instance, or if the creating method fails.
     */
    @Deprecated
    public Object createElement(final Project project, final Object parent, final String elementName)
            throws BuildException {
        final NestedCreator nc = getNestedCreator(project, "", parent, elementName, null);
        try {
            final Object nestedElement = nc.create(project, parent, null);
            if (project != null) {
                project.setProjectReference(nestedElement);
            }
            return nestedElement;
        } catch (final IllegalAccessException | InstantiationException ie) {
            // impossible as getMethods should only return public methods
            throw new BuildException(ie);
        } catch (final InvocationTargetException ite) {
            throw extractBuildException(ite);
        }
    }

    
returns an object that creates and stores an object
for an element of a parent.
Params:
project –      Project to which the parent object belongs.
parentUri –    The namespace uri of the parent object.
parent –       Parent object used to create the creator object to
                    create and store and instance of a subelement.
elementName –  Name of the element to create an instance of.
ue –           The unknown element associated with the element.
Returns:
a creator object to create and store the element instance./**
     * returns an object that creates and stores an object
     * for an element of a parent.
     *
     * @param project      Project to which the parent object belongs.
     * @param parentUri    The namespace uri of the parent object.
     * @param parent       Parent object used to create the creator object to
     *                     create and store and instance of a subelement.
     * @param elementName  Name of the element to create an instance of.
     * @param ue           The unknown element associated with the element.
     * @return a creator object to create and store the element instance.
     */
    public Creator getElementCreator(
        final Project project, final String parentUri, final Object parent, final String elementName, final UnknownElement ue) {
        final NestedCreator nc = getNestedCreator(project, parentUri, parent, elementName, ue);
        return new Creator(project, parent, nc);
    }

    
Indicates whether the introspected class is a dynamic one,
supporting arbitrary nested elements and/or attributes.
See Also:
DynamicElement
DynamicElementNS
Returns:
true if the introspected class is dynamic;
        false otherwise.
Since:
Ant 1.6.3/**
     * Indicates whether the introspected class is a dynamic one,
     * supporting arbitrary nested elements and/or attributes.
     *
     * @return <div><code>true</code> if the introspected class is dynamic;
     *         <code>false</code> otherwise.</div>
     * @since Ant 1.6.3
     *
     * @see DynamicElement
     * @see DynamicElementNS
     */
    public boolean isDynamic() {
        return DynamicElement.class.isAssignableFrom(bean)
                || DynamicElementNS.class.isAssignableFrom(bean);
    }

    
Indicates whether the introspected class is a task container,
supporting arbitrary nested tasks/types.
See Also:
TaskContainer
Returns:
true if the introspected class is a container;
        false otherwise.
Since:
Ant 1.6.3/**
     * Indicates whether the introspected class is a task container,
     * supporting arbitrary nested tasks/types.
     *
     * @return <code>true</code> if the introspected class is a container;
     *         <code>false</code> otherwise.
     * @since Ant 1.6.3
     *
     * @see TaskContainer
     */
    public boolean isContainer() {
        return TaskContainer.class.isAssignableFrom(bean);
    }

    
Indicates if this element supports a nested element of the
given name.
Params:
elementName – the name of the nested element being checked
Returns:
true if the given nested element is supported/**
     * Indicates if this element supports a nested element of the
     * given name.
     *
     * @param elementName the name of the nested element being checked
     *
     * @return true if the given nested element is supported
     */
    public boolean supportsNestedElement(final String elementName) {
        return supportsNestedElement("", elementName);
    }

    
Indicate if this element supports a nested element of the
given name.
Note that this method will always return true if the introspected class is dynamic or contains a method named "add" with void return type and a single argument. To ge a more thorough answer, use the four-arg version of this method instead.
Params:
parentUri –   the uri of the parent
elementName – the name of the nested element being checked
Returns:
true if the given nested element is supported/**
     * Indicate if this element supports a nested element of the
     * given name.
     *
     * <p>Note that this method will always return true if the
     * introspected class is {@link #isDynamic dynamic} or contains a
     * method named "add" with void return type and a single argument.
     * To ge a more thorough answer, use the four-arg version of this
     * method instead.</p>
     *
     * @param parentUri   the uri of the parent
     * @param elementName the name of the nested element being checked
     *
     * @return true if the given nested element is supported
     */
    public boolean supportsNestedElement(final String parentUri, final String elementName) {
        return isDynamic() || !addTypeMethods.isEmpty()
                || supportsReflectElement(parentUri, elementName);
    }

    
Indicate if this element supports a nested element of the
given name.
Note that this method will always return true if the introspected class is dynamic, so be prepared to catch an exception about unsupported children when calling getElementCreator.
Params:
parentUri –   the uri of the parent
elementName – the name of the nested element being checked
project – currently executing project instance
parent – the parent element
Returns:
true if the given nested element is supported
Since:
Ant 1.8.0./**
     * Indicate if this element supports a nested element of the
     * given name.
     *
     * <p>Note that this method will always return true if the
     * introspected class is {@link #isDynamic dynamic}, so be
     * prepared to catch an exception about unsupported children when
     * calling {@link #getElementCreator getElementCreator}.</p>
     *
     * @param parentUri   the uri of the parent
     * @param elementName the name of the nested element being checked
     * @param project currently executing project instance
     * @param parent the parent element
     *
     * @return true if the given nested element is supported
     * @since Ant 1.8.0.
     */
    public boolean supportsNestedElement(final String parentUri, final String elementName,
                                         final Project project, final Object parent) {
        return !addTypeMethods.isEmpty()
                && createAddTypeCreator(project, parent, elementName) != null
                || isDynamic() || supportsReflectElement(parentUri, elementName);
    }

    
Check if this element supports a nested element from reflection.
Params:
parentUri –   the uri of the parent
elementName – the name of the nested element being checked
Returns:
true if the given nested element is supported
Since:
Ant 1.8.0/**
     * Check if this element supports a nested element from reflection.
     *
     * @param parentUri   the uri of the parent
     * @param elementName the name of the nested element being checked
     *
     * @return true if the given nested element is supported
     * @since Ant 1.8.0
     */
    public boolean supportsReflectElement(
        String parentUri, final String elementName) {
        final String name = ProjectHelper.extractNameFromComponentName(elementName);
        if (!nestedCreators.containsKey(name.toLowerCase(Locale.ENGLISH))) {
            return false;
        }
        String uri = ProjectHelper.extractUriFromComponentName(elementName);
        if (uri.equals(ProjectHelper.ANT_CORE_URI) || uri.isEmpty()) {
            return true;
        }
        if (parentUri.equals(ProjectHelper.ANT_CORE_URI)) {
            parentUri = "";
        }
        return uri.equals(parentUri);
    }

    
Stores a named nested element using a storage method determined
by the initial introspection. If no appropriate storage method
is available, this method returns immediately.
Params:
project – Ignored in this implementation.
               May be null.
parent –  Parent instance to store the child in.
               Must not be null.
child –   Child instance to store in the parent.
               Should not be null.
elementName –  Name of the child element to store.
                    May be null, in which case
                    this method returns immediately.
Throws:
BuildException – if the storage method fails./**
     * Stores a named nested element using a storage method determined
     * by the initial introspection. If no appropriate storage method
     * is available, this method returns immediately.
     *
     * @param project Ignored in this implementation.
     *                May be <code>null</code>.
     *
     * @param parent  Parent instance to store the child in.
     *                Must not be <code>null</code>.
     *
     * @param child   Child instance to store in the parent.
     *                Should not be <code>null</code>.
     *
     * @param elementName  Name of the child element to store.
     *                     May be <code>null</code>, in which case
     *                     this method returns immediately.
     *
     * @exception BuildException if the storage method fails.
     */
    public void storeElement(final Project project, final Object parent, final Object child,
        final String elementName) throws BuildException {
        if (elementName == null) {
            return;
        }
        final NestedCreator ns = nestedCreators.get(elementName.toLowerCase(Locale.ENGLISH));
        if (ns == null) {
            return;
        }
        try {
            ns.store(parent, child);
        } catch (final IllegalAccessException | InstantiationException ie) {
            // impossible as getMethods should only return public methods
            throw new BuildException(ie);
        } catch (final InvocationTargetException ite) {
            throw extractBuildException(ite);
        }
    }

    
Helper method to extract the inner fault from an InvocationTargetException, and turn it into a BuildException. If it is already a BuildException, it is type cast and returned; if not a new BuildException is created containing the child as nested text. 
Params:
ite – the exception
Returns:
the nested exception/**
     * Helper method to extract the inner fault from an {@link InvocationTargetException}, and turn
     * it into a BuildException. If it is already a BuildException, it is type cast and returned; if
     * not a new BuildException is created containing the child as nested text.
     * @param ite the exception
     * @return the nested exception
     */
    private static BuildException extractBuildException(final InvocationTargetException ite) {
        final Throwable t = ite.getTargetException();
        if (t instanceof BuildException) {
            return (BuildException) t;
        }
        return new BuildException(t);
    }

    
Returns the type of a named nested element.
Params:
elementName – The name of the element to find the type of.
                   Must not be null.
Throws:
BuildException – if the introspected class does not
                          support the named nested element.
Returns:
the type of the nested element with the specified name.
        This will never be null./**
     * Returns the type of a named nested element.
     *
     * @param elementName The name of the element to find the type of.
     *                    Must not be <code>null</code>.
     *
     * @return the type of the nested element with the specified name.
     *         This will never be <code>null</code>.
     *
     * @exception BuildException if the introspected class does not
     *                           support the named nested element.
     */
    public Class<?> getElementType(final String elementName) throws BuildException {
        final Class<?> nt = nestedTypes.get(elementName);
        if (nt == null) {
            throw new UnsupportedElementException("Class "
                    + bean.getName() + " doesn't support the nested \""
                    + elementName + "\" element.", elementName);
        }
        return nt;
    }

    
Returns the type of a named attribute.
Params:
attributeName – The name of the attribute to find the type of.
                     Must not be null.
Throws:
BuildException – if the introspected class does not
                          support the named attribute.
Returns:
the type of the attribute with the specified name.
        This will never be null./**
     * Returns the type of a named attribute.
     *
     * @param attributeName The name of the attribute to find the type of.
     *                      Must not be <code>null</code>.
     *
     * @return the type of the attribute with the specified name.
     *         This will never be <code>null</code>.
     *
     * @exception BuildException if the introspected class does not
     *                           support the named attribute.
     */
    public Class<?> getAttributeType(final String attributeName) throws BuildException {
        final Class<?> at = attributeTypes.get(attributeName);
        if (at == null) {
            throw new UnsupportedAttributeException("Class "
                    + bean.getName() + " doesn't support the \""
                    + attributeName + "\" attribute.", attributeName);
        }
        return at;
    }

    
Returns the addText method when the introspected
class supports nested text.
Throws:
BuildException – if the introspected class does not
        support the nested text.
Returns:
the method on this introspected class that adds nested text.
        Cannot be null.
Since:
Ant 1.6.3/**
     * Returns the addText method when the introspected
     * class supports nested text.
     *
     * @return the method on this introspected class that adds nested text.
     *         Cannot be <code>null</code>.
     * @throws BuildException if the introspected class does not
     *         support the nested text.
     * @since Ant 1.6.3
     */
    public Method getAddTextMethod() throws BuildException {
        if (!supportsCharacters()) {
            throw new BuildException("Class " + bean.getName()
                    + " doesn't support nested text data.");
        }
        return addText;
    }

    
Returns the adder or creator method of a named nested element.
Params:
elementName – The name of the attribute to find the setter
        method of. Must not be null.
Throws:
BuildException – if the introspected class does not
        support the named nested element.
Returns:
the method on this introspected class that adds or creates this
        nested element. Can be null when the introspected
        class is a dynamic configurator!
Since:
Ant 1.6.3/**
     * Returns the adder or creator method of a named nested element.
     *
     * @param  elementName The name of the attribute to find the setter
     *         method of. Must not be <code>null</code>.
     * @return the method on this introspected class that adds or creates this
     *         nested element. Can be <code>null</code> when the introspected
     *         class is a dynamic configurator!
     * @throws BuildException if the introspected class does not
     *         support the named nested element.
     * @since Ant 1.6.3
     */
    public Method getElementMethod(final String elementName) throws BuildException {
        final NestedCreator creator = nestedCreators.get(elementName);
        if (creator == null) {
            throw new UnsupportedElementException("Class "
                    + bean.getName() + " doesn't support the nested \""
                    + elementName + "\" element.", elementName);
        }
        return creator.method;
    }

    
Returns the setter method of a named attribute.
Params:
attributeName – The name of the attribute to find the setter
        method of. Must not be null.
Throws:
BuildException – if the introspected class does not
        support the named attribute.
Returns:
the method on this introspected class that sets this attribute.
        This will never be null.
Since:
Ant 1.6.3/**
     * Returns the setter method of a named attribute.
     *
     * @param  attributeName The name of the attribute to find the setter
     *         method of. Must not be <code>null</code>.
     * @return the method on this introspected class that sets this attribute.
     *         This will never be <code>null</code>.
     * @throws BuildException if the introspected class does not
     *         support the named attribute.
     * @since Ant 1.6.3
     */
    public Method getAttributeMethod(final String attributeName) throws BuildException {
        final AttributeSetter setter = attributeSetters.get(attributeName);
        if (setter == null) {
            throw new UnsupportedAttributeException("Class "
                    + bean.getName() + " doesn't support the \""
                    + attributeName + "\" attribute.", attributeName);
        }
        return setter.method;
    }

    
Returns whether or not the introspected class supports PCDATA.
Returns:
whether or not the introspected class supports PCDATA./**
     * Returns whether or not the introspected class supports PCDATA.
     *
     * @return whether or not the introspected class supports PCDATA.
     */
    public boolean supportsCharacters() {
        return addText != null;
    }

    
Returns an enumeration of the names of the attributes supported by the introspected class.
See Also:
getAttributeMap
Returns:
an enumeration of the names of the attributes supported by the introspected class./**
     * Returns an enumeration of the names of the attributes supported by the introspected class.
     *
     * @return an enumeration of the names of the attributes supported by the introspected class.
     * @see #getAttributeMap
     */
    public Enumeration<String> getAttributes() {
        return Collections.enumeration(attributeSetters.keySet());
    }

    
Returns a read-only map of attributes supported by the introspected class.
Returns:
an attribute name to attribute Class
        unmodifiable map. Can be empty, but never null.
Since:
Ant 1.6.3/**
     * Returns a read-only map of attributes supported by the introspected class.
     *
     * @return an attribute name to attribute <code>Class</code>
     *         unmodifiable map. Can be empty, but never <code>null</code>.
     * @since Ant 1.6.3
     */
    public Map<String, Class<?>> getAttributeMap() {
        return attributeTypes.isEmpty()
            ? Collections.emptyMap() : Collections.unmodifiableMap(attributeTypes);
    }

    
Returns an enumeration of the names of the nested elements supported
by the introspected class.
See Also:
getNestedElementMap
Returns:
an enumeration of the names of the nested elements supported
        by the introspected class./**
     * Returns an enumeration of the names of the nested elements supported
     * by the introspected class.
     *
     * @return an enumeration of the names of the nested elements supported
     *         by the introspected class.
     * @see #getNestedElementMap
     */
    public Enumeration<String> getNestedElements() {
        return Collections.enumeration(nestedTypes.keySet());
    }

    
Returns a read-only map of nested elements supported
by the introspected class.
Returns:
a nested-element name to nested-element Class
        unmodifiable map. Can be empty, but never null.
Since:
Ant 1.6.3/**
     * Returns a read-only map of nested elements supported
     * by the introspected class.
     *
     * @return a nested-element name to nested-element <code>Class</code>
     *         unmodifiable map. Can be empty, but never <code>null</code>.
     * @since Ant 1.6.3
     */
    public Map<String, Class<?>> getNestedElementMap() {
        return nestedTypes.isEmpty()
            ? Collections.emptyMap() : Collections.unmodifiableMap(nestedTypes);
    }

    
Returns a read-only list of extension points supported
by the introspected class.

A task/type or nested element with void methods named add()
or addConfigured(), taking a single class or interface
argument, supports extensions point. This method returns the list of
all these void add[Configured](type) methods.
Returns:
a list of void, single argument add() or addConfigured()
        Methods of all supported extension points.
        These methods are sorted such that if the argument type of a
        method derives from another type also an argument of a method
        of this list, the method with the most derived argument will
        always appear first. Can be empty, but never null.
Since:
Ant 1.6.3/**
     * Returns a read-only list of extension points supported
     * by the introspected class.
     * <p>
     * A task/type or nested element with void methods named <code>add()</code>
     * or <code>addConfigured()</code>, taking a single class or interface
     * argument, supports extensions point. This method returns the list of
     * all these <em>void add[Configured](type)</em> methods.
     *
     * @return a list of void, single argument add() or addConfigured()
     *         <code>Method</code>s of all supported extension points.
     *         These methods are sorted such that if the argument type of a
     *         method derives from another type also an argument of a method
     *         of this list, the method with the most derived argument will
     *         always appear first. Can be empty, but never <code>null</code>.
     * @since Ant 1.6.3
     */
    public List<Method> getExtensionPoints() {
        return addTypeMethods.isEmpty()
                ? Collections.emptyList() : Collections.unmodifiableList(addTypeMethods);
    }

    
Creates an implementation of AttributeSetter for the given
attribute type. Conversions (where necessary) are automatically
made for the following types:

String (left as it is)
Character/char (first character is used)
Boolean/boolean (Project.toBoolean(String) is used) 
Class (Class.forName is used)
File (resolved relative to the appropriate project)
Path (resolve relative to the appropriate project)
Resource (resolved as a FileResource relative to the appropriate project)
FileProvider (resolved as a FileResource relative to the appropriate project)
EnumeratedAttribute (uses its own setValue method) 
Other primitive types (wrapper classes are used with constructors
taking String)

If none of the above covers the given parameters, a constructor for the
appropriate class taking a String parameter is used if it is available.
Params:
m – The method to invoke on the bean when the setter is invoked.
         Must not be null.
arg – The type of the single argument of the bean's method.
           Must not be null.
attrName – the name of the attribute for which the setter is being
                created.
Returns:
an appropriate AttributeSetter instance, or null
        if no appropriate conversion is available./**
     * Creates an implementation of AttributeSetter for the given
     * attribute type. Conversions (where necessary) are automatically
     * made for the following types:
     * <ul>
     * <li>String (left as it is)
     * <li>Character/char (first character is used)
     * <li>Boolean/boolean
     * ({@link Project#toBoolean(String) Project.toBoolean(String)} is used)
     * <li>Class (Class.forName is used)
     * <li>File (resolved relative to the appropriate project)
     * <li>Path (resolve relative to the appropriate project)
     * <li>Resource (resolved as a FileResource relative to the appropriate project)
     * <li>FileProvider (resolved as a FileResource relative to the appropriate project)
     * <li>EnumeratedAttribute (uses its own
     * {@link EnumeratedAttribute#setValue(String) setValue} method)
     * <li>Other primitive types (wrapper classes are used with constructors
     * taking String)
     * </ul>
     *
     * If none of the above covers the given parameters, a constructor for the
     * appropriate class taking a String parameter is used if it is available.
     *
     * @param m The method to invoke on the bean when the setter is invoked.
     *          Must not be <code>null</code>.
     * @param arg The type of the single argument of the bean's method.
     *            Must not be <code>null</code>.
     * @param attrName the name of the attribute for which the setter is being
     *                 created.
     *
     * @return an appropriate AttributeSetter instance, or <code>null</code>
     *         if no appropriate conversion is available.
     */
    private AttributeSetter createAttributeSetter(final Method m,
                                                  final Class<?> arg,
                                                  final String attrName) {
        // use wrappers for primitive classes, e.g. int and
        // Integer are treated identically
        final Class<?> reflectedArg = PRIMITIVE_TYPE_MAP.getOrDefault(arg, arg);

        // Object.class - it gets handled differently by AttributeSetter
        if (java.lang.Object.class == reflectedArg) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException,
                    IllegalAccessException {
                    throw new BuildException(
                        "Internal ant problem - this should not get called");
                }
            };
        }
        // simplest case - setAttribute expects String
        if (String.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException {
                    m.invoke(parent, (Object[]) new String[] {value});
                }
            };
        }
        // char and Character get special treatment - take the first character
        if (java.lang.Character.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException {
                    if (value.isEmpty()) {
                        throw new BuildException("The value \"\" is not a "
                                + "legal value for attribute \"" + attrName + "\"");
                    }
                    m.invoke(parent, (Object[]) new Character[] {value.charAt(0)});
                }
            };
        }
        // boolean and Boolean get special treatment because we have a nice method in Project
        if (java.lang.Boolean.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException {
                    m.invoke(parent, (Object[]) new Boolean[] {
                            Project.toBoolean(value) ? Boolean.TRUE : Boolean.FALSE });
                }
            };
        }
        // Class doesn't have a String constructor but a decent factory method
        if (java.lang.Class.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException, BuildException {
                    try {
                        m.invoke(parent, Class.forName(value));
                    } catch (final ClassNotFoundException ce) {
                        throw new BuildException(ce);
                    }
                }
            };
        }
        // resolve relative paths through Project
        if (java.io.File.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException {
                    m.invoke(parent, p.resolveFile(value));
                }
            };
        }
        // resolve relative nio paths through Project
        if (java.nio.file.Path.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException {
                    m.invoke(parent, p.resolveFile(value).toPath());
                }
            };
        }

        // resolve Resources/FileProviders as FileResources relative to Project:
        if (Resource.class.equals(reflectedArg) || FileProvider.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException, BuildException {
                    m.invoke(parent, new FileResource(p, p.resolveFile(value)));
                }
            };
        }
        // EnumeratedAttributes have their own helper class
        if (EnumeratedAttribute.class.isAssignableFrom(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException, BuildException {
                    try {
                        final EnumeratedAttribute ea = (EnumeratedAttribute) reflectedArg.newInstance();
                        ea.setValue(value);
                        m.invoke(parent, ea);
                    } catch (final InstantiationException ie) {
                        throw new BuildException(ie);
                    }
                }
            };
        }

        final AttributeSetter setter = getEnumSetter(reflectedArg, m, arg);
        if (setter != null) {
            return setter;
        }

        if (java.lang.Long.class.equals(reflectedArg)) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                        throws InvocationTargetException, IllegalAccessException, BuildException {
                    try {
                        m.invoke(parent, StringUtils.parseHumanSizes(value));
                    } catch (final NumberFormatException e) {
                        throw new BuildException("Can't assign non-numeric"
                                                 + " value '" + value + "' to"
                                                 + " attribute " + attrName);
                    } catch (final InvocationTargetException | IllegalAccessException e) {
                        throw e;
                    } catch (final Exception e) {
                        throw new BuildException(e);
                    }
                }
            };
        }
        // worst case. look for a public String constructor and use it
        // also supports new Whatever(Project, String) as for Path or Reference
        // This is used (deliberately) for all primitives/wrappers other than
        // char, boolean, and long.
        boolean includeProject;
        Constructor<?> c;
        try {
            // First try with Project.
            c = reflectedArg.getConstructor(Project.class, String.class);
            includeProject = true;
        } catch (final NoSuchMethodException nme) {
            // OK, try without.
            try {
                c = reflectedArg.getConstructor(String.class);
                includeProject = false;
            } catch (final NoSuchMethodException nme2) {
                // Well, no matching constructor.
                return null;
            }
        }
        final boolean finalIncludeProject = includeProject;
        final Constructor<?> finalConstructor = c;

        return new AttributeSetter(m, arg) {
            @Override
            public void set(final Project p, final Object parent, final String value)
                    throws InvocationTargetException, IllegalAccessException, BuildException {
                try {
                    final Object[] args = finalIncludeProject
                            ? new Object[] {p, value} : new Object[] {value};

                    final Object attribute = finalConstructor.newInstance(args);
                    if (p != null) {
                        p.setProjectReference(attribute);
                    }
                    m.invoke(parent, attribute);
                } catch (final InvocationTargetException e) {
                    final Throwable cause = e.getCause();
                    if (cause instanceof IllegalArgumentException) {
                        throw new BuildException("Can't assign value '" + value
                                                 + "' to attribute " + attrName
                                                 + ", reason: "
                                                 + cause.getClass()
                                                 + " with message '"
                                                 + cause.getMessage() + "'");
                    }
                    throw e;
                } catch (final InstantiationException ie) {
                    throw new BuildException(ie);
                }
            }
        };
    }

    private AttributeSetter getEnumSetter(
        final Class<?> reflectedArg, final Method m, final Class<?> arg) {
        if (reflectedArg.isEnum()) {
            return new AttributeSetter(m, arg) {
                @Override
                public void set(final Project p, final Object parent, final String value)
                    throws InvocationTargetException, IllegalAccessException,
                    BuildException {
                    Enum<?> setValue;
                    try {
                        @SuppressWarnings({ "unchecked", "rawtypes" })
                        final Enum<?> enumValue = Enum.valueOf((Class<? extends Enum>) reflectedArg,
                                value);
                        setValue = enumValue;
                    } catch (final IllegalArgumentException e) {
                        // there is a specific logic here for the value
                        // being out of the allowed set of enumerations.
                        throw new BuildException("'" + value + "' is not a permitted value for "
                                + reflectedArg.getName());
                    }
                    m.invoke(parent, setValue);
                }
            };
        }
        return null;
    }

    
Returns a description of the type of the given element in
relation to a given project. This is used for logging purposes
when the element is asked to cope with some data it has no way of handling.
Params:
project – The project the element is defined in. Must not be null.
element – The element to describe. Must not be null.
Returns:
a description of the element type/**
     * Returns a description of the type of the given element in
     * relation to a given project. This is used for logging purposes
     * when the element is asked to cope with some data it has no way of handling.
     *
     * @param project The project the element is defined in. Must not be <code>null</code>.
     *
     * @param element The element to describe. Must not be <code>null</code>.
     *
     * @return a description of the element type
     */
    private String getElementName(final Project project, final Object element) {
        return project.getElementName(element);
    }

    
Extracts the name of a property from a method name by subtracting
a given prefix and converting into lower case. It is up to calling
code to make sure the method name does actually begin with the
specified prefix - no checking is done in this method.
Params:
methodName – The name of the method in question. Must not be null.
prefix –     The prefix to remove. Must not be null.
Returns:
the lower-cased method name with the prefix removed./**
     * Extracts the name of a property from a method name by subtracting
     * a given prefix and converting into lower case. It is up to calling
     * code to make sure the method name does actually begin with the
     * specified prefix - no checking is done in this method.
     *
     * @param methodName The name of the method in question. Must not be <code>null</code>.
     * @param prefix     The prefix to remove. Must not be <code>null</code>.
     *
     * @return the lower-cased method name with the prefix removed.
     */
    private static String getPropertyName(final String methodName, final String prefix) {
        return methodName.substring(prefix.length()).toLowerCase(Locale.ENGLISH);
    }

    
creator - allows use of create/store external
to IntrospectionHelper.
The class is final as it has a private constructor.
/**
     * creator - allows use of create/store external
     * to IntrospectionHelper.
     * The class is final as it has a private constructor.
     */
    public static final class Creator {
        private final NestedCreator nestedCreator;
        private final Object parent;
        private final Project project;
        private Object nestedObject;
        private String polyType;

        
Creates a new Creator instance.
This object is given to the UnknownElement to create
objects for sub-elements. UnknownElement calls
create to create an object, the object then gets
configured and then UnknownElement calls store.
SetPolyType may be used to override the type used
to create the object with. SetPolyType gets called before create.
Params:
project – the current project
parent –  the parent object to create the object in
nestedCreator – the nested creator object to use/**
         * Creates a new Creator instance.
         * This object is given to the UnknownElement to create
         * objects for sub-elements. UnknownElement calls
         * create to create an object, the object then gets
         * configured and then UnknownElement calls store.
         * SetPolyType may be used to override the type used
         * to create the object with. SetPolyType gets called before create.
         *
         * @param project the current project
         * @param parent  the parent object to create the object in
         * @param nestedCreator the nested creator object to use
         */
        private Creator(final Project project, final Object parent, final NestedCreator nestedCreator) {
            this.project = project;
            this.parent = parent;
            this.nestedCreator = nestedCreator;
        }

        
Used to override the class used to create the object.
Params:
polyType – a ant component type name/**
         * Used to override the class used to create the object.
         *
         * @param polyType a ant component type name
         */
        public void setPolyType(final String polyType) {
            this.polyType = polyType;
        }

        
Create an object using this creator, which is determined by introspection.
Returns:
the created object/**
         * Create an object using this creator, which is determined by introspection.
         *
         * @return the created object
         */
        public Object create() {
            if (polyType != null) {
                if (!nestedCreator.isPolyMorphic()) {
                    throw new BuildException(
                            "Not allowed to use the polymorphic form for this element");
                }
                final ComponentHelper helper = ComponentHelper.getComponentHelper(project);
                nestedObject = helper.createComponent(polyType);
                if (nestedObject == null) {
                    throw new BuildException("Unable to create object of type " + polyType);
                }
            }
            try {
                nestedObject = nestedCreator.create(project, parent, nestedObject);
                if (project != null) {
                    project.setProjectReference(nestedObject);
                }
                return nestedObject;
            } catch (final IllegalAccessException | InstantiationException ex) {
                throw new BuildException(ex);
            } catch (final IllegalArgumentException ex) {
                if (polyType == null) {
                    throw ex;
                }
                throw new BuildException("Invalid type used " + polyType);
            } catch (final InvocationTargetException ex) {
                throw extractBuildException(ex);
            }
        }

        
Returns:
the real object (used currently only for presetdef)./**
         * @return the real object (used currently only for presetdef).
         */
        public Object getRealObject() {
            return nestedCreator.getRealObject();
        }

        
Stores the nested element object using a storage method determined by introspection.
/**
         * Stores the nested element object using a storage method determined by introspection.
         *
         */
        public void store() {
            try {
                nestedCreator.store(parent, nestedObject);
            } catch (final IllegalAccessException | InstantiationException ex) {
                throw new BuildException(ex);
            } catch (final IllegalArgumentException ex) {
                if (polyType == null) {
                    throw ex;
                }
                throw new BuildException("Invalid type used " + polyType);
            } catch (final InvocationTargetException ex) {
                throw extractBuildException(ex);
            }
        }
    }

    
Internal interface used to create nested elements. Not documented
in detail for reasons of source code readability.
/**
     * Internal interface used to create nested elements. Not documented
     * in detail for reasons of source code readability.
     */
    private abstract static class NestedCreator {
        private final Method method; // the method called to add/create the nested element

        protected NestedCreator(final Method m) {
            method = m;
        }
        Method getMethod() {
            return method;
        }
        boolean isPolyMorphic() {
            return false;
        }
        Object getRealObject() {
            return null;
        }
        abstract Object create(Project project, Object parent, Object child)
                throws InvocationTargetException, IllegalAccessException, InstantiationException;

        void store(final Object parent, final Object child)
                 throws InvocationTargetException, IllegalAccessException, InstantiationException {
            // DO NOTHING
        }
    }

    private static class CreateNestedCreator extends NestedCreator {
        CreateNestedCreator(final Method m) {
            super(m);
        }

        @Override
        Object create(final Project project, final Object parent, final Object ignore)
                throws InvocationTargetException, IllegalAccessException {
            return getMethod().invoke(parent);
        }
    }

    
Version to use for addXXX and addConfiguredXXX /** Version to use for addXXX and addConfiguredXXX */
    private static class AddNestedCreator extends NestedCreator {

        static final int ADD = 1;
        static final int ADD_CONFIGURED = 2;

        private final Constructor<?> constructor;
        private final int behavior; // ADD or ADD_CONFIGURED

        AddNestedCreator(final Method m, final Constructor<?> c, final int behavior) {
            super(m);
            this.constructor = c;
            this.behavior = behavior;
        }

        @Override
        boolean isPolyMorphic() {
            return true;
        }

        @Override
        Object create(final Project project, final Object parent, Object child)
                throws InvocationTargetException, IllegalAccessException, InstantiationException {
            if (child == null) {
                child = constructor.newInstance(
                        constructor.getParameterTypes().length == 0
                                ? new Object[] {} : new Object[] {project});
            }
            if (child instanceof PreSetDef.PreSetDefinition) {
                child = ((PreSetDef.PreSetDefinition) child).createObject(project);
            }
            if (behavior == ADD) {
                istore(parent, child);
            }
            return child;
        }

        @Override
        void store(final Object parent, final Object child)
                throws InvocationTargetException, IllegalAccessException, InstantiationException {
            if (behavior == ADD_CONFIGURED) {
                istore(parent, child);
            }
        }

        private void istore(final Object parent, final Object child)
                throws InvocationTargetException, IllegalAccessException {
            getMethod().invoke(parent, child);
        }
    }

    
Internal interface used to setting element attributes. Not documented
in detail for reasons of source code readability.
/**
     * Internal interface used to setting element attributes. Not documented
     * in detail for reasons of source code readability.
     */
    private abstract static class AttributeSetter {
        private final Method method; // the method called to set the attribute
        private final Class<?> type;
        protected AttributeSetter(final Method m, final Class<?> type) {
            method = m;
            this.type = type;
        }
        void setObject(final Project p, final Object parent, final Object value)
                throws InvocationTargetException, IllegalAccessException, BuildException {
            if (type != null) {
                Class<?> useType = type;
                if (type.isPrimitive()) {
                    if (value == null) {
                        throw new BuildException(
                            "Attempt to set primitive "
                            + getPropertyName(method.getName(), "set")
                            + " to null on " + parent);
                    }
                    useType = PRIMITIVE_TYPE_MAP.get(type);
                }
                if (value == null || useType.isInstance(value)) {
                    method.invoke(parent, value);
                    return;
                }
            }
            set(p, parent, value.toString());
        }
        abstract void set(Project p, Object parent, String value)
                throws InvocationTargetException, IllegalAccessException, BuildException;
    }

    
Clears the static cache of on build finished.
/**
     * Clears the static cache of on build finished.
     */
    public static synchronized void clearCache() {
        HELPERS.clear();
    }

    
Create a NestedCreator for the given element.
Params:
project – owning project
parent – Parent object used to create the instance.
elementName – name of the element
Throws:
BuildException – if something goes wrong
Returns:
a nested creator, or null if there is no component of the given name, or it
       has no matching add type methods/**
     * Create a NestedCreator for the given element.
     * @param project owning project
     * @param parent Parent object used to create the instance.
     * @param elementName name of the element
     * @return a nested creator, or null if there is no component of the given name, or it
     *        has no matching add type methods
     * @throws BuildException if something goes wrong
     */
    private NestedCreator createAddTypeCreator(
            final Project project, final Object parent, final String elementName) throws BuildException {
        if (addTypeMethods.isEmpty()) {
            return null;
        }
        final ComponentHelper helper = ComponentHelper.getComponentHelper(project);

        final MethodAndObject restricted =  createRestricted(helper, elementName, addTypeMethods);
        final MethodAndObject topLevel = createTopLevel(helper, elementName, addTypeMethods);

        if (restricted == null && topLevel == null) {
            return null;
        }

        if (restricted != null && topLevel != null) {
            throw new BuildException(
                "ambiguous: type and component definitions for "
                + elementName);
        }

        final MethodAndObject methodAndObject = restricted == null ? topLevel : restricted;

        Object rObject = methodAndObject.object;
        if (methodAndObject.object instanceof PreSetDef.PreSetDefinition) {
            rObject = ((PreSetDef.PreSetDefinition) methodAndObject.object)
                .createObject(project);
        }
        final Object nestedObject = methodAndObject.object;
        final Object realObject = rObject;

        return new NestedCreator(methodAndObject.method) {
            @Override
            Object create(final Project project, final Object parent, final Object ignore)
                    throws InvocationTargetException, IllegalAccessException {
                if (!getMethod().getName().endsWith("Configured")) {
                    getMethod().invoke(parent, realObject);
                }
                return nestedObject;
            }

            @Override
            Object getRealObject() {
                return realObject;
            }

            @Override
            void store(final Object parent, final Object child) throws InvocationTargetException,
                    IllegalAccessException, InstantiationException {
                if (getMethod().getName().endsWith("Configured")) {
                    getMethod().invoke(parent, realObject);
                }
            }
        };
    }

    
Inserts an add or addConfigured method into
the addTypeMethods array. The array is
ordered so that the more derived classes are first.
If both add and addConfigured are present, the addConfigured will take priority.
Params:
method – the Method to insert./**
     * Inserts an add or addConfigured method into
     * the addTypeMethods array. The array is
     * ordered so that the more derived classes are first.
     * If both add and addConfigured are present, the addConfigured will take priority.
     * @param method the <code>Method</code> to insert.
     */
    private void insertAddTypeMethod(final Method method) {
        final Class<?> argClass = method.getParameterTypes()[0];
        final int size = addTypeMethods.size();
        for (int c = 0; c < size; ++c) {
            final Method current = addTypeMethods.get(c);
            if (current.getParameterTypes()[0].equals(argClass)) {
                if ("addConfigured".equals(method.getName())) {
                    // add configured replaces the add method
                    addTypeMethods.set(c, method);
                }
                return; // Already present
            }
            if (current.getParameterTypes()[0].isAssignableFrom(argClass)) {
                addTypeMethods.add(c, method);
                return; // higher derived
            }
        }
        addTypeMethods.add(method);
    }

    
Search the list of methods to find the first method
that has a parameter that accepts the nested element object.
Params:
paramClass – the Class type to search for.
methods – the List of methods to search.
Returns:
a matching Method; null if none found./**
     * Search the list of methods to find the first method
     * that has a parameter that accepts the nested element object.
     * @param paramClass the <code>Class</code> type to search for.
     * @param methods the <code>List</code> of methods to search.
     * @return a matching <code>Method</code>; null if none found.
     */
    private Method findMatchingMethod(final Class<?> paramClass, final List<Method> methods) {
        if (paramClass == null) {
            return null;
        }
        Class<?> matchedClass = null;
        Method matchedMethod = null;

        for (final Method method : methods) {
            final Class<?> methodClass = method.getParameterTypes()[0];
            if (methodClass.isAssignableFrom(paramClass)) {
                if (matchedClass == null) {
                    matchedClass = methodClass;
                    matchedMethod = method;
                } else if (!methodClass.isAssignableFrom(matchedClass)) {
                    throw new BuildException("ambiguous: types " + matchedClass.getName() + " and "
                            + methodClass.getName() + " match " + paramClass.getName());
                }
            }
        }
        return matchedMethod;
    }

    private String condenseText(final String text) {
        if (text.length() <= MAX_REPORT_NESTED_TEXT) {
            return text;
        }
        final int ends = (MAX_REPORT_NESTED_TEXT - ELLIPSIS.length()) / 2;
        return new StringBuffer(text).replace(ends, text.length() - ends, ELLIPSIS).toString();
    }


    private static class MethodAndObject {
        private final Method method;
        private final Object object;
        public MethodAndObject(final Method method, final Object object) {
            this.method = method;
            this.object = object;
        }
    }

    /**
     *
     */
    private AntTypeDefinition findRestrictedDefinition(
        final ComponentHelper helper, final String componentName, final List<Method> methods) {
        AntTypeDefinition definition = null;
        Class<?> matchedDefinitionClass = null;

        final List<AntTypeDefinition> definitions = helper.getRestrictedDefinitions(componentName);
        if (definitions == null) {
            return null;
        }
        synchronized (definitions) {
            for (final AntTypeDefinition d : definitions) {
                final Class<?> exposedClass = d.getExposedClass(helper.getProject());
                if (exposedClass == null) {
                    continue;
                }
                final Method method = findMatchingMethod(exposedClass, methods);
                if (method == null) {
                    continue;
                }
                if (matchedDefinitionClass != null) {
                    throw new BuildException(
                        "ambiguous: restricted definitions for "
                        + componentName + " "
                        + matchedDefinitionClass + " and " + exposedClass);
                }
                matchedDefinitionClass = exposedClass;
                definition = d;
            }
        }
        return definition;
    }

    private MethodAndObject createRestricted(
        final ComponentHelper helper, final String elementName, final List<Method> addTypeMethods) {

        final Project project = helper.getProject();

        final AntTypeDefinition restrictedDefinition =
            findRestrictedDefinition(helper, elementName, addTypeMethods);

        if (restrictedDefinition == null) {
            return null;
        }

        final Method addMethod = findMatchingMethod(
            restrictedDefinition.getExposedClass(project), addTypeMethods);
        if (addMethod == null) {
            throw new BuildException("Ant Internal Error - contract mismatch for "
                    + elementName);
        }
        final Object addedObject = restrictedDefinition.create(project);
        if (addedObject == null) {
            throw new BuildException(
                "Failed to create object " + elementName
                + " of type " + restrictedDefinition.getTypeClass(project));
        }
        return new MethodAndObject(addMethod, addedObject);
    }

    private MethodAndObject createTopLevel(
        final ComponentHelper helper, final String elementName, final List<Method> methods) {
        final Class<?> clazz = helper.getComponentClass(elementName);
        if (clazz == null) {
            return null;
        }
        final Method addMethod = findMatchingMethod(clazz, addTypeMethods);
        if (addMethod == null) {
            return null;
        }
        final Object addedObject = helper.createComponent(elementName);
        return new MethodAndObject(addMethod, addedObject);
    }

}