https://openjdk.java.net/ 
/*
 * Copyright (c) 1996, 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */
package java.beans;

import com.sun.beans.TypeResolver;
import com.sun.beans.WeakCache;
import com.sun.beans.finder.ClassFinder;
import com.sun.beans.introspect.ClassInfo;
import com.sun.beans.introspect.EventSetInfo;
import com.sun.beans.introspect.PropertyInfo;

import java.awt.Component;

import java.lang.ref.Reference;
import java.lang.ref.SoftReference;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;

import java.util.Map;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.EventObject;
import java.util.List;
import java.util.TreeMap;

import jdk.internal.misc.JavaBeansAccess;
import jdk.internal.misc.SharedSecrets;
import sun.reflect.misc.ReflectUtil;


The Introspector class provides a standard way for tools to learn about
the properties, events, and methods supported by a target Java Bean.


For each of those three kinds of information, the Introspector will
separately analyze the bean's class and superclasses looking for
either explicit or implicit information and use that information to
build a BeanInfo object that comprehensively describes the target bean.


For each class "Foo", explicit information may be available if there exists
a corresponding "FooBeanInfo" class that provides a non-null value when
queried for the information.   We first look for the BeanInfo class by
taking the full package-qualified name of the target bean class and
appending "BeanInfo" to form a new class name.  If this fails, then
we take the final classname component of this name, and look for that
class in each of the packages specified in the BeanInfo package search
path.


Thus for a class such as "sun.xyz.OurButton" we would first look for a
BeanInfo class called "sun.xyz.OurButtonBeanInfo" and if that failed we'd
look in each package in the BeanInfo search path for an OurButtonBeanInfo
class.  With the default search path, this would mean looking for
"sun.beans.infos.OurButtonBeanInfo".


If a class provides explicit BeanInfo about itself then we add that to
the BeanInfo information we obtained from analyzing any derived classes,
but we regard the explicit information as being definitive for the current
class and its base classes, and do not proceed any further up the superclass
chain.


If we don't find explicit BeanInfo on a class, we use low-level
reflection to study the methods of the class and apply standard design
patterns to identify property accessors, event sources, or public
methods.  We then proceed to analyze the class's superclass and add
in the information from it (and possibly on up the superclass chain).


For more information about introspection and design patterns, please
consult the
 JavaBeans™ specification.

Since:1.1
/**
 * The Introspector class provides a standard way for tools to learn about
 * the properties, events, and methods supported by a target Java Bean.
 * <p>
 * For each of those three kinds of information, the Introspector will
 * separately analyze the bean's class and superclasses looking for
 * either explicit or implicit information and use that information to
 * build a BeanInfo object that comprehensively describes the target bean.
 * <p>
 * For each class "Foo", explicit information may be available if there exists
 * a corresponding "FooBeanInfo" class that provides a non-null value when
 * queried for the information.   We first look for the BeanInfo class by
 * taking the full package-qualified name of the target bean class and
 * appending "BeanInfo" to form a new class name.  If this fails, then
 * we take the final classname component of this name, and look for that
 * class in each of the packages specified in the BeanInfo package search
 * path.
 * <p>
 * Thus for a class such as "sun.xyz.OurButton" we would first look for a
 * BeanInfo class called "sun.xyz.OurButtonBeanInfo" and if that failed we'd
 * look in each package in the BeanInfo search path for an OurButtonBeanInfo
 * class.  With the default search path, this would mean looking for
 * "sun.beans.infos.OurButtonBeanInfo".
 * <p>
 * If a class provides explicit BeanInfo about itself then we add that to
 * the BeanInfo information we obtained from analyzing any derived classes,
 * but we regard the explicit information as being definitive for the current
 * class and its base classes, and do not proceed any further up the superclass
 * chain.
 * <p>
 * If we don't find explicit BeanInfo on a class, we use low-level
 * reflection to study the methods of the class and apply standard design
 * patterns to identify property accessors, event sources, or public
 * methods.  We then proceed to analyze the class's superclass and add
 * in the information from it (and possibly on up the superclass chain).
 * <p>
 * For more information about introspection and design patterns, please
 * consult the
 *  <a href="http://www.oracle.com/technetwork/java/javase/documentation/spec-136004.html">JavaBeans&trade; specification</a>.
 *
 * @since 1.1
 */

public class Introspector {

    // Flags that can be used to control getBeanInfo:
    
Flag to indicate to use of all beaninfo.

Since:1.2
/**
     * Flag to indicate to use of all beaninfo.
     * @since 1.2
     */
    public static final int USE_ALL_BEANINFO           = 1;
    
Flag to indicate to ignore immediate beaninfo.

Since:1.2
/**
     * Flag to indicate to ignore immediate beaninfo.
     * @since 1.2
     */
    public static final int IGNORE_IMMEDIATE_BEANINFO  = 2;
    
Flag to indicate to ignore all beaninfo.

Since:1.2
/**
     * Flag to indicate to ignore all beaninfo.
     * @since 1.2
     */
    public static final int IGNORE_ALL_BEANINFO        = 3;

    // Static Caches to speed up introspection.
    private static final WeakCache<Class<?>, Method[]> declaredMethodCache = new WeakCache<>();

    private Class<?> beanClass;
    private BeanInfo explicitBeanInfo;
    private BeanInfo superBeanInfo;
    private BeanInfo additionalBeanInfo[];

    private boolean propertyChangeSource = false;

    // These should be removed.
    private String defaultEventName;
    private String defaultPropertyName;
    private int defaultEventIndex = -1;
    private int defaultPropertyIndex = -1;

    // Methods maps from Method names to MethodDescriptors
    private Map<String, MethodDescriptor> methods;

    // properties maps from String names to PropertyDescriptors
    private Map<String, PropertyDescriptor> properties;

    // events maps from String names to EventSetDescriptors
    private Map<String, EventSetDescriptor> events;

    private static final EventSetDescriptor[] EMPTY_EVENTSETDESCRIPTORS = new EventSetDescriptor[0];

    static final String ADD_PREFIX = "add";
    static final String REMOVE_PREFIX = "remove";
    static final String GET_PREFIX = "get";
    static final String SET_PREFIX = "set";
    static final String IS_PREFIX = "is";

    // register with SharedSecrets for JMX usage
    static {
        SharedSecrets.setJavaBeansAccess(new JavaBeansAccess() {
            @Override
            public Method getReadMethod(Class<?> clazz, String property) throws Exception {
                BeanInfo bi = Introspector.getBeanInfo(clazz);
                PropertyDescriptor[] pds = bi.getPropertyDescriptors();
                for (PropertyDescriptor pd: pds) {
                    if (pd.getName().equals(property)) {
                        return pd.getReadMethod();
                    }
                }
                return null;
            }

            @Override
            public String[] getConstructorPropertiesValue(Constructor<?> ctr) {
                ConstructorProperties cp = ctr.getAnnotation(ConstructorProperties.class);
                String [] ret = cp != null ? cp.value() : null;
                return ret;
            }
        });
    }

    //======================================================================
    //                          Public methods
    //======================================================================

    
Introspect on a Java Bean and learn about all its properties, exposed
methods, and events.


If the BeanInfo class for a Java Bean has been previously Introspected
then the BeanInfo class is retrieved from the BeanInfo cache.

Params:
  • beanClass –  The bean class to be analyzed.
Throws:
See Also:
Returns: A BeanInfo object describing the target bean.
/**
     * Introspect on a Java Bean and learn about all its properties, exposed
     * methods, and events.
     * <p>
     * If the BeanInfo class for a Java Bean has been previously Introspected
     * then the BeanInfo class is retrieved from the BeanInfo cache.
     *
     * @param beanClass  The bean class to be analyzed.
     * @return  A BeanInfo object describing the target bean.
     * @exception IntrospectionException if an exception occurs during
     *              introspection.
     * @see #flushCaches
     * @see #flushFromCaches
     */
    public static BeanInfo getBeanInfo(Class<?> beanClass)
        throws IntrospectionException
    {
        if (!ReflectUtil.isPackageAccessible(beanClass)) {
            return (new Introspector(beanClass, null, USE_ALL_BEANINFO)).getBeanInfo();
        }
        ThreadGroupContext context = ThreadGroupContext.getContext();
        BeanInfo beanInfo;
        synchronized (declaredMethodCache) {
            beanInfo = context.getBeanInfo(beanClass);
        }
        if (beanInfo == null) {
            beanInfo = new Introspector(beanClass, null, USE_ALL_BEANINFO).getBeanInfo();
            synchronized (declaredMethodCache) {
                context.putBeanInfo(beanClass, beanInfo);
            }
        }
        return beanInfo;
    }

    
Introspect on a Java bean and learn about all its properties, exposed
methods, and events, subject to some control flags.


If the BeanInfo class for a Java Bean has been previously Introspected
based on the same arguments then the BeanInfo class is retrieved
from the BeanInfo cache.

Params:
  • beanClass –  The bean class to be analyzed.
  • flags –  Flags to control the introspection.
    If flags == USE_ALL_BEANINFO then we use all of the BeanInfo
         classes we can discover.
    If flags == IGNORE_IMMEDIATE_BEANINFO then we ignore any
          BeanInfo associated with the specified beanClass.
    If flags == IGNORE_ALL_BEANINFO then we ignore all BeanInfo
          associated with the specified beanClass or any of its
          parent classes.
Throws:
Returns: A BeanInfo object describing the target bean.
Since:1.2
/**
     * Introspect on a Java bean and learn about all its properties, exposed
     * methods, and events, subject to some control flags.
     * <p>
     * If the BeanInfo class for a Java Bean has been previously Introspected
     * based on the same arguments then the BeanInfo class is retrieved
     * from the BeanInfo cache.
     *
     * @param beanClass  The bean class to be analyzed.
     * @param flags  Flags to control the introspection.
     *     If flags == USE_ALL_BEANINFO then we use all of the BeanInfo
     *          classes we can discover.
     *     If flags == IGNORE_IMMEDIATE_BEANINFO then we ignore any
     *           BeanInfo associated with the specified beanClass.
     *     If flags == IGNORE_ALL_BEANINFO then we ignore all BeanInfo
     *           associated with the specified beanClass or any of its
     *           parent classes.
     * @return  A BeanInfo object describing the target bean.
     * @exception IntrospectionException if an exception occurs during
     *              introspection.
     * @since 1.2
     */
    public static BeanInfo getBeanInfo(Class<?> beanClass, int flags)
                                                throws IntrospectionException {
        return getBeanInfo(beanClass, null, flags);
    }

    
Introspect on a Java bean and learn all about its properties, exposed
methods, below a given "stop" point.


If the BeanInfo class for a Java Bean has been previously Introspected
based on the same arguments, then the BeanInfo class is retrieved
from the BeanInfo cache.

Params:
  • beanClass – The bean class to be analyzed.
  • stopClass – The baseclass at which to stop the analysis.  Any
   methods/properties/events in the stopClass or in its baseclasses
   will be ignored in the analysis.
Throws:
Returns:the BeanInfo for the bean
/**
     * Introspect on a Java bean and learn all about its properties, exposed
     * methods, below a given "stop" point.
     * <p>
     * If the BeanInfo class for a Java Bean has been previously Introspected
     * based on the same arguments, then the BeanInfo class is retrieved
     * from the BeanInfo cache.
     * @return the BeanInfo for the bean
     * @param beanClass The bean class to be analyzed.
     * @param stopClass The baseclass at which to stop the analysis.  Any
     *    methods/properties/events in the stopClass or in its baseclasses
     *    will be ignored in the analysis.
     * @exception IntrospectionException if an exception occurs during
     *              introspection.
     */
    public static BeanInfo getBeanInfo(Class<?> beanClass, Class<?> stopClass)
                                                throws IntrospectionException {
        return getBeanInfo(beanClass, stopClass, USE_ALL_BEANINFO);
    }

    
Introspect on a Java Bean and learn about all its properties, exposed methods and events, below a given stopClass point subject to some control flags. 

 
USE_ALL_BEANINFO

 
Any BeanInfo that can be discovered will be used.

 
IGNORE_IMMEDIATE_BEANINFO

 
Any BeanInfo associated with the specified beanClass will be ignored.

 
IGNORE_ALL_BEANINFO

 
Any BeanInfo associated with the specified beanClass or any of its parent classes will be ignored.


 Any methods/properties/events in the stopClass or in its parent classes will be ignored in the analysis. 

If the BeanInfo class for a Java Bean has been
previously introspected based on the same arguments then
the BeanInfo class is retrieved from the BeanInfo cache.

Params:
  • beanClass –  the bean class to be analyzed
  • stopClass –  the parent class at which to stop the analysis
  • flags –      flags to control the introspection
Throws:
Returns:a BeanInfo object describing the target bean
Since:1.7
/**
     * Introspect on a Java Bean and learn about all its properties,
     * exposed methods and events, below a given {@code stopClass} point
     * subject to some control {@code flags}.
     * <dl>
     *  <dt>USE_ALL_BEANINFO</dt>
     *  <dd>Any BeanInfo that can be discovered will be used.</dd>
     *  <dt>IGNORE_IMMEDIATE_BEANINFO</dt>
     *  <dd>Any BeanInfo associated with the specified {@code beanClass} will be ignored.</dd>
     *  <dt>IGNORE_ALL_BEANINFO</dt>
     *  <dd>Any BeanInfo associated with the specified {@code beanClass}
     *      or any of its parent classes will be ignored.</dd>
     * </dl>
     * Any methods/properties/events in the {@code stopClass}
     * or in its parent classes will be ignored in the analysis.
     * <p>
     * If the BeanInfo class for a Java Bean has been
     * previously introspected based on the same arguments then
     * the BeanInfo class is retrieved from the BeanInfo cache.
     *
     * @param beanClass  the bean class to be analyzed
     * @param stopClass  the parent class at which to stop the analysis
     * @param flags      flags to control the introspection
     * @return a BeanInfo object describing the target bean
     * @exception IntrospectionException if an exception occurs during introspection
     *
     * @since 1.7
     */
    public static BeanInfo getBeanInfo(Class<?> beanClass, Class<?> stopClass,
                                        int flags) throws IntrospectionException {
        BeanInfo bi;
        if (stopClass == null && flags == USE_ALL_BEANINFO) {
            // Same parameters to take advantage of caching.
            bi = getBeanInfo(beanClass);
        } else {
            bi = (new Introspector(beanClass, stopClass, flags)).getBeanInfo();
        }
        return bi;

        // Old behaviour: Make an independent copy of the BeanInfo.
        //return new GenericBeanInfo(bi);
    }


    
Utility method to take a string and convert it to normal Java variable
name capitalization.  This normally means converting the first
character from upper case to lower case, but in the (unusual) special
case when there is more than one character and both the first and
second characters are upper case, we leave it alone.


Thus "FooBah" becomes "fooBah" and "X" becomes "x", but "URL" stays
as "URL".

Params:
  • name – The string to be decapitalized.
Returns: The decapitalized version of the string.
/**
     * Utility method to take a string and convert it to normal Java variable
     * name capitalization.  This normally means converting the first
     * character from upper case to lower case, but in the (unusual) special
     * case when there is more than one character and both the first and
     * second characters are upper case, we leave it alone.
     * <p>
     * Thus "FooBah" becomes "fooBah" and "X" becomes "x", but "URL" stays
     * as "URL".
     *
     * @param  name The string to be decapitalized.
     * @return  The decapitalized version of the string.
     */
    public static String decapitalize(String name) {
        if (name == null || name.length() == 0) {
            return name;
        }
        if (name.length() > 1 && Character.isUpperCase(name.charAt(1)) &&
                        Character.isUpperCase(name.charAt(0))){
            return name;
        }
        char chars[] = name.toCharArray();
        chars[0] = Character.toLowerCase(chars[0]);
        return new String(chars);
    }

    
Gets the list of package names that will be used for
         finding BeanInfo classes.

Returns: The array of package names that will be searched in
         order to find BeanInfo classes. The default value
         for this array is implementation-dependent; e.g.
         Sun implementation initially sets to {"sun.beans.infos"}.
/**
     * Gets the list of package names that will be used for
     *          finding BeanInfo classes.
     *
     * @return  The array of package names that will be searched in
     *          order to find BeanInfo classes. The default value
     *          for this array is implementation-dependent; e.g.
     *          Sun implementation initially sets to {"sun.beans.infos"}.
     */

    public static String[] getBeanInfoSearchPath() {
        return ThreadGroupContext.getContext().getBeanInfoFinder().getPackages();
    }

    
Change the list of package names that will be used for
         finding BeanInfo classes.  The behaviour of
         this method is undefined if parameter path
         is null.

First, if there is a security manager, its checkPropertiesAccess method is called. This could result in a SecurityException. 
Params:
  • path –  Array of package names.
Throws:
  • SecurityException –  if a security manager exists and its checkPropertiesAccess method doesn't allow setting of system properties.
See Also:
/**
     * Change the list of package names that will be used for
     *          finding BeanInfo classes.  The behaviour of
     *          this method is undefined if parameter path
     *          is null.
     *
     * <p>First, if there is a security manager, its {@code checkPropertiesAccess}
     * method is called. This could result in a SecurityException.
     *
     * @param path  Array of package names.
     * @exception  SecurityException  if a security manager exists and its
     *             {@code checkPropertiesAccess} method doesn't allow setting
     *              of system properties.
     * @see SecurityManager#checkPropertiesAccess
     */

    public static void setBeanInfoSearchPath(String[] path) {
        SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            sm.checkPropertiesAccess();
        }
        ThreadGroupContext.getContext().getBeanInfoFinder().setPackages(path);
    }


    
Flush all of the Introspector's internal caches.  This method is
not normally required.  It is normally only needed by advanced
tools that update existing "Class" objects in-place and need
to make the Introspector re-analyze existing Class objects.

Since:1.2
/**
     * Flush all of the Introspector's internal caches.  This method is
     * not normally required.  It is normally only needed by advanced
     * tools that update existing "Class" objects in-place and need
     * to make the Introspector re-analyze existing Class objects.
     *
     * @since 1.2
     */

    public static void flushCaches() {
        synchronized (declaredMethodCache) {
            ThreadGroupContext.getContext().clearBeanInfoCache();
            declaredMethodCache.clear();
        }
    }

    
Flush the Introspector's internal cached information for a given class.
This method is not normally required.  It is normally only needed
by advanced tools that update existing "Class" objects in-place
and need to make the Introspector re-analyze an existing Class object.
Note that only the direct state associated with the target Class
object is flushed.  We do not flush state for other Class objects
with the same name, nor do we flush state for any related Class
objects (such as subclasses), even though their state may include
information indirectly obtained from the target Class object.

Params:
  • clz –  Class object to be flushed.
Throws:
Since:1.2
/**
     * Flush the Introspector's internal cached information for a given class.
     * This method is not normally required.  It is normally only needed
     * by advanced tools that update existing "Class" objects in-place
     * and need to make the Introspector re-analyze an existing Class object.
     *
     * Note that only the direct state associated with the target Class
     * object is flushed.  We do not flush state for other Class objects
     * with the same name, nor do we flush state for any related Class
     * objects (such as subclasses), even though their state may include
     * information indirectly obtained from the target Class object.
     *
     * @param clz  Class object to be flushed.
     * @throws NullPointerException If the Class object is null.
     * @since 1.2
     */
    public static void flushFromCaches(Class<?> clz) {
        if (clz == null) {
            throw new NullPointerException();
        }
        synchronized (declaredMethodCache) {
            ThreadGroupContext.getContext().removeBeanInfo(clz);
            declaredMethodCache.put(clz, null);
        }
    }

    //======================================================================
    //                  Private implementation methods
    //======================================================================

    private Introspector(Class<?> beanClass, Class<?> stopClass, int flags)
                                            throws IntrospectionException {
        this.beanClass = beanClass;

        // Check stopClass is a superClass of startClass.
        if (stopClass != null) {
            boolean isSuper = false;
            for (Class<?> c = beanClass.getSuperclass(); c != null; c = c.getSuperclass()) {
                if (c == stopClass) {
                    isSuper = true;
                }
            }
            if (!isSuper) {
                throw new IntrospectionException(stopClass.getName() + " not superclass of " +
                                        beanClass.getName());
            }
        }

        if (flags == USE_ALL_BEANINFO) {
            explicitBeanInfo = findExplicitBeanInfo(beanClass);
        }

        Class<?> superClass = beanClass.getSuperclass();
        if (superClass != stopClass) {
            int newFlags = flags;
            if (newFlags == IGNORE_IMMEDIATE_BEANINFO) {
                newFlags = USE_ALL_BEANINFO;
            }
            superBeanInfo = getBeanInfo(superClass, stopClass, newFlags);
        }
        if (explicitBeanInfo != null) {
            additionalBeanInfo = explicitBeanInfo.getAdditionalBeanInfo();
        }
        if (additionalBeanInfo == null) {
            additionalBeanInfo = new BeanInfo[0];
        }
    }

    
Constructs a GenericBeanInfo class from the state of the Introspector

/**
     * Constructs a GenericBeanInfo class from the state of the Introspector
     */
    private BeanInfo getBeanInfo() throws IntrospectionException {

        // the evaluation order here is import, as we evaluate the
        // event sets and locate PropertyChangeListeners before we
        // look for properties.
        BeanDescriptor bd = getTargetBeanDescriptor();
        MethodDescriptor mds[] = getTargetMethodInfo();
        EventSetDescriptor esds[] = getTargetEventInfo();
        PropertyDescriptor pds[] = getTargetPropertyInfo();

        int defaultEvent = getTargetDefaultEventIndex();
        int defaultProperty = getTargetDefaultPropertyIndex();

        return new GenericBeanInfo(bd, esds, defaultEvent, pds,
                        defaultProperty, mds, explicitBeanInfo);

    }

    
Looks for an explicit BeanInfo class that corresponds to the Class.
First it looks in the existing package that the Class is defined in,
then it checks to see if the class is its own BeanInfo. Finally,
the BeanInfo search path is prepended to the class and searched.

Params:
  • beanClass –  the class type of the bean
Returns:Instance of an explicit BeanInfo class or null if one isn't found.
/**
     * Looks for an explicit BeanInfo class that corresponds to the Class.
     * First it looks in the existing package that the Class is defined in,
     * then it checks to see if the class is its own BeanInfo. Finally,
     * the BeanInfo search path is prepended to the class and searched.
     *
     * @param beanClass  the class type of the bean
     * @return Instance of an explicit BeanInfo class or null if one isn't found.
     */
    private static BeanInfo findExplicitBeanInfo(Class<?> beanClass) {
        return ThreadGroupContext.getContext().getBeanInfoFinder().find(beanClass);
    }

    
Returns:An array of PropertyDescriptors describing the editable
properties supported by the target bean.
/**
     * @return An array of PropertyDescriptors describing the editable
     * properties supported by the target bean.
     */

    private PropertyDescriptor[] getTargetPropertyInfo() {

        // Check if the bean has its own BeanInfo that will provide
        // explicit information.
        PropertyDescriptor[] explicitProperties = null;
        if (explicitBeanInfo != null) {
            explicitProperties = getPropertyDescriptors(this.explicitBeanInfo);
        }

        if (explicitProperties == null && superBeanInfo != null) {
            // We have no explicit BeanInfo properties.  Check with our parent.
            addPropertyDescriptors(getPropertyDescriptors(this.superBeanInfo));
        }

        for (int i = 0; i < additionalBeanInfo.length; i++) {
            addPropertyDescriptors(additionalBeanInfo[i].getPropertyDescriptors());
        }

        if (explicitProperties != null) {
            // Add the explicit BeanInfo data to our results.
            addPropertyDescriptors(explicitProperties);

        } else {
            // Apply some reflection to the current class.
            for (Map.Entry<String,PropertyInfo> entry : ClassInfo.get(this.beanClass).getProperties().entrySet()) {
                addPropertyDescriptor(null != entry.getValue().getIndexed()
                        ? new IndexedPropertyDescriptor(entry, this.propertyChangeSource)
                        : new PropertyDescriptor(entry, this.propertyChangeSource));
            }
            JavaBean annotation = this.beanClass.getAnnotation(JavaBean.class);
            if ((annotation != null) && !annotation.defaultProperty().isEmpty()) {
                this.defaultPropertyName = annotation.defaultProperty();
            }
        }
        processPropertyDescriptors();

        // Allocate and populate the result array.
        PropertyDescriptor result[] =
                properties.values().toArray(new PropertyDescriptor[properties.size()]);

        // Set the default index.
        if (defaultPropertyName != null) {
            for (int i = 0; i < result.length; i++) {
                if (defaultPropertyName.equals(result[i].getName())) {
                    defaultPropertyIndex = i;
                }
            }
        }
        return result;
    }

    private HashMap<String, List<PropertyDescriptor>> pdStore = new HashMap<>();

    
Adds the property descriptor to the list store.

/**
     * Adds the property descriptor to the list store.
     */
    private void addPropertyDescriptor(PropertyDescriptor pd) {
        String propName = pd.getName();
        List<PropertyDescriptor> list = pdStore.get(propName);
        if (list == null) {
            list = new ArrayList<>();
            pdStore.put(propName, list);
        }
        if (this.beanClass != pd.getClass0()) {
            // replace existing property descriptor
            // only if we have types to resolve
            // in the context of this.beanClass
            Method read = pd.getReadMethod();
            Method write = pd.getWriteMethod();
            boolean cls = true;
            if (read != null) cls = cls && read.getGenericReturnType() instanceof Class;
            if (write != null) cls = cls && write.getGenericParameterTypes()[0] instanceof Class;
            if (pd instanceof IndexedPropertyDescriptor) {
                IndexedPropertyDescriptor ipd = (IndexedPropertyDescriptor) pd;
                Method readI = ipd.getIndexedReadMethod();
                Method writeI = ipd.getIndexedWriteMethod();
                if (readI != null) cls = cls && readI.getGenericReturnType() instanceof Class;
                if (writeI != null) cls = cls && writeI.getGenericParameterTypes()[1] instanceof Class;
                if (!cls) {
                    pd = new IndexedPropertyDescriptor(ipd);
                    pd.updateGenericsFor(this.beanClass);
                }
            }
            else if (!cls) {
                pd = new PropertyDescriptor(pd);
                pd.updateGenericsFor(this.beanClass);
            }
        }
        list.add(pd);
    }

    private void addPropertyDescriptors(PropertyDescriptor[] descriptors) {
        if (descriptors != null) {
            for (PropertyDescriptor descriptor : descriptors) {
                addPropertyDescriptor(descriptor);
            }
        }
    }

    private PropertyDescriptor[] getPropertyDescriptors(BeanInfo info) {
        PropertyDescriptor[] descriptors = info.getPropertyDescriptors();
        int index = info.getDefaultPropertyIndex();
        if ((0 <= index) && (index < descriptors.length)) {
            this.defaultPropertyName = descriptors[index].getName();
        }
        return descriptors;
    }

    
Populates the property descriptor table by merging the
lists of Property descriptors.

/**
     * Populates the property descriptor table by merging the
     * lists of Property descriptors.
     */
    private void processPropertyDescriptors() {
        if (properties == null) {
            properties = new TreeMap<>();
        }

        List<PropertyDescriptor> list;

        PropertyDescriptor pd, gpd, spd;
        IndexedPropertyDescriptor ipd, igpd, ispd;

        Iterator<List<PropertyDescriptor>> it = pdStore.values().iterator();
        while (it.hasNext()) {
            pd = null; gpd = null; spd = null;
            ipd = null; igpd = null; ispd = null;

            list = it.next();

            // First pass. Find the latest getter method. Merge properties
            // of previous getter methods.
            for (int i = 0; i < list.size(); i++) {
                pd = list.get(i);
                if (pd instanceof IndexedPropertyDescriptor) {
                    ipd = (IndexedPropertyDescriptor)pd;
                    if (ipd.getIndexedReadMethod() != null) {
                        if (igpd != null) {
                            igpd = new IndexedPropertyDescriptor(igpd, ipd);
                        } else {
                            igpd = ipd;
                        }
                    }
                } else {
                    if (pd.getReadMethod() != null) {
                        String pdName = pd.getReadMethod().getName();
                        if (gpd != null) {
                            // Don't replace the existing read
                            // method if it starts with "is"
                            String gpdName = gpd.getReadMethod().getName();
                            if (gpdName.equals(pdName) || !gpdName.startsWith(IS_PREFIX)) {
                                gpd = new PropertyDescriptor(gpd, pd);
                            }
                        } else {
                            gpd = pd;
                        }
                    }
                }
            }

            // Second pass. Find the latest setter method which
            // has the same type as the getter method.
            for (int i = 0; i < list.size(); i++) {
                pd = list.get(i);
                if (pd instanceof IndexedPropertyDescriptor) {
                    ipd = (IndexedPropertyDescriptor)pd;
                    if (ipd.getIndexedWriteMethod() != null) {
                        if (igpd != null) {
                            if (isAssignable(igpd.getIndexedPropertyType(), ipd.getIndexedPropertyType())) {
                                if (ispd != null) {
                                    ispd = new IndexedPropertyDescriptor(ispd, ipd);
                                } else {
                                    ispd = ipd;
                                }
                            }
                        } else {
                            if (ispd != null) {
                                ispd = new IndexedPropertyDescriptor(ispd, ipd);
                            } else {
                                ispd = ipd;
                            }
                        }
                    }
                } else {
                    if (pd.getWriteMethod() != null) {
                        if (gpd != null) {
                            if (isAssignable(gpd.getPropertyType(), pd.getPropertyType())) {
                                if (spd != null) {
                                    spd = new PropertyDescriptor(spd, pd);
                                } else {
                                    spd = pd;
                                }
                            }
                        } else {
                            if (spd != null) {
                                spd = new PropertyDescriptor(spd, pd);
                            } else {
                                spd = pd;
                            }
                        }
                    }
                }
            }

            // At this stage we should have either PDs or IPDs for the
            // representative getters and setters. The order at which the
            // property descriptors are determined represent the
            // precedence of the property ordering.
            pd = null; ipd = null;

            if (igpd != null && ispd != null) {
                // Complete indexed properties set
                // Merge any classic property descriptors
                if ((gpd == spd) || (gpd == null)) {
                    pd = spd;
                } else if (spd == null) {
                    pd = gpd;
                } else if (spd instanceof IndexedPropertyDescriptor) {
                    pd = mergePropertyWithIndexedProperty(gpd, (IndexedPropertyDescriptor) spd);
                } else if (gpd instanceof IndexedPropertyDescriptor) {
                    pd = mergePropertyWithIndexedProperty(spd, (IndexedPropertyDescriptor) gpd);
                } else {
                    pd = mergePropertyDescriptor(gpd, spd);
                }
                if (igpd == ispd) {
                    ipd = igpd;
                } else {
                    ipd = mergePropertyDescriptor(igpd, ispd);
                }
                if (pd == null) {
                    pd = ipd;
                } else {
                    Class<?> propType = pd.getPropertyType();
                    Class<?> ipropType = ipd.getIndexedPropertyType();
                    if (propType.isArray() && propType.getComponentType() == ipropType) {
                        pd = pd.getClass0().isAssignableFrom(ipd.getClass0())
                                ? new IndexedPropertyDescriptor(pd, ipd)
                                : new IndexedPropertyDescriptor(ipd, pd);
                    } else if (pd.getClass0().isAssignableFrom(ipd.getClass0())) {
                        pd = pd.getClass0().isAssignableFrom(ipd.getClass0())
                                ? new PropertyDescriptor(pd, ipd)
                                : new PropertyDescriptor(ipd, pd);
                    } else {
                        pd = ipd;
                    }
                }
            } else if (gpd != null && spd != null) {
                if (igpd != null) {
                    gpd = mergePropertyWithIndexedProperty(gpd, igpd);
                }
                if (ispd != null) {
                    spd = mergePropertyWithIndexedProperty(spd, ispd);
                }
                // Complete simple properties set
                if (gpd == spd) {
                    pd = gpd;
                } else if (spd instanceof IndexedPropertyDescriptor) {
                    pd = mergePropertyWithIndexedProperty(gpd, (IndexedPropertyDescriptor) spd);
                } else if (gpd instanceof IndexedPropertyDescriptor) {
                    pd = mergePropertyWithIndexedProperty(spd, (IndexedPropertyDescriptor) gpd);
                } else {
                    pd = mergePropertyDescriptor(gpd, spd);
                }
            } else if (ispd != null) {
                // indexed setter
                pd = ispd;
                // Merge any classic property descriptors
                if (spd != null) {
                    pd = mergePropertyDescriptor(ispd, spd);
                }
                if (gpd != null) {
                    pd = mergePropertyDescriptor(ispd, gpd);
                }
            } else if (igpd != null) {
                // indexed getter
                pd = igpd;
                // Merge any classic property descriptors
                if (gpd != null) {
                    pd = mergePropertyDescriptor(igpd, gpd);
                }
                if (spd != null) {
                    pd = mergePropertyDescriptor(igpd, spd);
                }
            } else if (spd != null) {
                // simple setter
                pd = spd;
            } else if (gpd != null) {
                // simple getter
                pd = gpd;
            }

            // Very special case to ensure that an IndexedPropertyDescriptor
            // doesn't contain less information than the enclosed
            // PropertyDescriptor. If it does, then recreate as a
            // PropertyDescriptor. See 4168833
            if (pd instanceof IndexedPropertyDescriptor) {
                ipd = (IndexedPropertyDescriptor)pd;
                if (ipd.getIndexedReadMethod() == null && ipd.getIndexedWriteMethod() == null) {
                    pd = new PropertyDescriptor(ipd);
                }
            }

            // Find the first property descriptor
            // which does not have getter and setter methods.
            // See regression bug 4984912.
            if ( (pd == null) && (list.size() > 0) ) {
                pd = list.get(0);
            }

            if (pd != null) {
                properties.put(pd.getName(), pd);
            }
        }
    }

    private static boolean isAssignable(Class<?> current, Class<?> candidate) {
        return ((current == null) || (candidate == null)) ? current == candidate : current.isAssignableFrom(candidate);
    }

    private PropertyDescriptor mergePropertyWithIndexedProperty(PropertyDescriptor pd, IndexedPropertyDescriptor ipd) {
        Class<?> type = pd.getPropertyType();
        if (type.isArray() && (type.getComponentType() == ipd.getIndexedPropertyType())) {
            return pd.getClass0().isAssignableFrom(ipd.getClass0())
                    ? new IndexedPropertyDescriptor(pd, ipd)
                    : new IndexedPropertyDescriptor(ipd, pd);
        }
        return pd;
    }

    
Adds the property descriptor to the indexedproperty descriptor only if the
types are the same.
The most specific property descriptor will take precedence.

/**
     * Adds the property descriptor to the indexedproperty descriptor only if the
     * types are the same.
     *
     * The most specific property descriptor will take precedence.
     */
    private PropertyDescriptor mergePropertyDescriptor(IndexedPropertyDescriptor ipd,
                                                       PropertyDescriptor pd) {
        PropertyDescriptor result = null;

        Class<?> propType = pd.getPropertyType();
        Class<?> ipropType = ipd.getIndexedPropertyType();

        if (propType.isArray() && propType.getComponentType() == ipropType) {
            if (pd.getClass0().isAssignableFrom(ipd.getClass0())) {
                result = new IndexedPropertyDescriptor(pd, ipd);
            } else {
                result = new IndexedPropertyDescriptor(ipd, pd);
            }
        } else if ((ipd.getReadMethod() == null) && (ipd.getWriteMethod() == null)) {
            if (pd.getClass0().isAssignableFrom(ipd.getClass0())) {
                result = new PropertyDescriptor(pd, ipd);
            } else {
                result = new PropertyDescriptor(ipd, pd);
            }
        } else {
            // Cannot merge the pd because of type mismatch
            // Return the most specific pd
            if (pd.getClass0().isAssignableFrom(ipd.getClass0())) {
                result = ipd;
            } else {
                result = pd;
                // Try to add methods which may have been lost in the type change
                // See 4168833
                Method write = result.getWriteMethod();
                Method read = result.getReadMethod();

                if (read == null && write != null) {
                    read = findMethod(result.getClass0(),
                                      GET_PREFIX + NameGenerator.capitalize(result.getName()), 0);
                    if (read != null) {
                        try {
                            result.setReadMethod(read);
                        } catch (IntrospectionException ex) {
                            // no consequences for failure.
                        }
                    }
                }
                if (write == null && read != null) {
                    write = findMethod(result.getClass0(),
                                       SET_PREFIX + NameGenerator.capitalize(result.getName()), 1,
                                       new Class<?>[] { FeatureDescriptor.getReturnType(result.getClass0(), read) });
                    if (write != null) {
                        try {
                            result.setWriteMethod(write);
                        } catch (IntrospectionException ex) {
                            // no consequences for failure.
                        }
                    }
                }
            }
        }
        return result;
    }

    // Handle regular pd merge
    private PropertyDescriptor mergePropertyDescriptor(PropertyDescriptor pd1,
                                                       PropertyDescriptor pd2) {
        if (pd1.getClass0().isAssignableFrom(pd2.getClass0())) {
            return new PropertyDescriptor(pd1, pd2);
        } else {
            return new PropertyDescriptor(pd2, pd1);
        }
    }

    // Handle regular ipd merge
    private IndexedPropertyDescriptor mergePropertyDescriptor(IndexedPropertyDescriptor ipd1,
                                                       IndexedPropertyDescriptor ipd2) {
        if (ipd1.getClass0().isAssignableFrom(ipd2.getClass0())) {
            return new IndexedPropertyDescriptor(ipd1, ipd2);
        } else {
            return new IndexedPropertyDescriptor(ipd2, ipd1);
        }
    }

    
Returns:An array of EventSetDescriptors describing the kinds of
events fired by the target bean.
/**
     * @return An array of EventSetDescriptors describing the kinds of
     * events fired by the target bean.
     */
    private EventSetDescriptor[] getTargetEventInfo() throws IntrospectionException {
        if (events == null) {
            events = new HashMap<>();
        }

        // Check if the bean has its own BeanInfo that will provide
        // explicit information.
        EventSetDescriptor[] explicitEvents = null;
        if (explicitBeanInfo != null) {
            explicitEvents = explicitBeanInfo.getEventSetDescriptors();
            int ix = explicitBeanInfo.getDefaultEventIndex();
            if (ix >= 0 && ix < explicitEvents.length) {
                defaultEventName = explicitEvents[ix].getName();
            }
        }

        if (explicitEvents == null && superBeanInfo != null) {
            // We have no explicit BeanInfo events.  Check with our parent.
            EventSetDescriptor supers[] = superBeanInfo.getEventSetDescriptors();
            for (int i = 0 ; i < supers.length; i++) {
                addEvent(supers[i]);
            }
            int ix = superBeanInfo.getDefaultEventIndex();
            if (ix >= 0 && ix < supers.length) {
                defaultEventName = supers[ix].getName();
            }
        }

        for (int i = 0; i < additionalBeanInfo.length; i++) {
            EventSetDescriptor additional[] = additionalBeanInfo[i].getEventSetDescriptors();
            if (additional != null) {
                for (int j = 0 ; j < additional.length; j++) {
                    addEvent(additional[j]);
                }
            }
        }

        if (explicitEvents != null) {
            // Add the explicit explicitBeanInfo data to our results.
            for (int i = 0 ; i < explicitEvents.length; i++) {
                addEvent(explicitEvents[i]);
            }

        } else {
            // Apply some reflection to the current class.
            for (Map.Entry<String,EventSetInfo> entry : ClassInfo.get(this.beanClass).getEventSets().entrySet()) {
                    // generate a list of Method objects for each of the target methods:
                List<Method> methods = new ArrayList<>();
                for (Method method : ClassInfo.get(entry.getValue().getListenerType()).getMethods()) {
                    if (isEventHandler(method)) {
                        methods.add(method);
                    }
                }
                addEvent(new EventSetDescriptor(
                        entry.getKey(),
                        entry.getValue(),
                        methods.toArray(new Method[methods.size()])));
            }
            JavaBean annotation = this.beanClass.getAnnotation(JavaBean.class);
            if ((annotation != null) && !annotation.defaultEventSet().isEmpty()) {
                this.defaultEventName = annotation.defaultEventSet();
            }
        }
        EventSetDescriptor[] result;
        if (events.size() == 0) {
            result = EMPTY_EVENTSETDESCRIPTORS;
        } else {
            // Allocate and populate the result array.
            result = new EventSetDescriptor[events.size()];
            result = events.values().toArray(result);
            // Set the default index.
            if (defaultEventName != null) {
                for (int i = 0; i < result.length; i++) {
                    if (defaultEventName.equals(result[i].getName())) {
                        defaultEventIndex = i;
                    }
                }
            }
        }
        return result;
    }

    private void addEvent(EventSetDescriptor esd) {
        String key = esd.getName();
        if (esd.getName().equals("propertyChange")) {
            propertyChangeSource = true;
        }
        EventSetDescriptor old = events.get(key);
        if (old == null) {
            events.put(key, esd);
            return;
        }
        EventSetDescriptor composite = new EventSetDescriptor(old, esd);
        events.put(key, composite);
    }

    
Returns:An array of MethodDescriptors describing the private
methods supported by the target bean.
/**
     * @return An array of MethodDescriptors describing the private
     * methods supported by the target bean.
     */
    private MethodDescriptor[] getTargetMethodInfo() {
        if (methods == null) {
            methods = new HashMap<>(100);
        }

        // Check if the bean has its own BeanInfo that will provide
        // explicit information.
        MethodDescriptor[] explicitMethods = null;
        if (explicitBeanInfo != null) {
            explicitMethods = explicitBeanInfo.getMethodDescriptors();
        }

        if (explicitMethods == null && superBeanInfo != null) {
            // We have no explicit BeanInfo methods.  Check with our parent.
            MethodDescriptor supers[] = superBeanInfo.getMethodDescriptors();
            for (int i = 0 ; i < supers.length; i++) {
                addMethod(supers[i]);
            }
        }

        for (int i = 0; i < additionalBeanInfo.length; i++) {
            MethodDescriptor additional[] = additionalBeanInfo[i].getMethodDescriptors();
            if (additional != null) {
                for (int j = 0 ; j < additional.length; j++) {
                    addMethod(additional[j]);
                }
            }
        }

        if (explicitMethods != null) {
            // Add the explicit explicitBeanInfo data to our results.
            for (int i = 0 ; i < explicitMethods.length; i++) {
                addMethod(explicitMethods[i]);
            }

        } else {
            // Apply some reflection to the current class.
            for (Method method : ClassInfo.get(this.beanClass).getMethods()) {
                addMethod(new MethodDescriptor(method));
            }
        }

        // Allocate and populate the result array.
        MethodDescriptor result[] = new MethodDescriptor[methods.size()];
        result = methods.values().toArray(result);

        return result;
    }

    private void addMethod(MethodDescriptor md) {
        // We have to be careful here to distinguish method by both name
        // and argument lists.
        // This method gets called a *lot, so we try to be efficient.
        String name = md.getName();

        MethodDescriptor old = methods.get(name);
        if (old == null) {
            // This is the common case.
            methods.put(name, md);
            return;
        }

        // We have a collision on method names.  This is rare.

        // Check if old and md have the same type.
        String[] p1 = md.getParamNames();
        String[] p2 = old.getParamNames();

        boolean match = false;
        if (p1.length == p2.length) {
            match = true;
            for (int i = 0; i < p1.length; i++) {
                if (p1[i] != p2[i]) {
                    match = false;
                    break;
                }
            }
        }
        if (match) {
            MethodDescriptor composite = new MethodDescriptor(old, md);
            methods.put(name, composite);
            return;
        }

        // We have a collision on method names with different type signatures.
        // This is very rare.

        String longKey = makeQualifiedMethodName(name, p1);
        old = methods.get(longKey);
        if (old == null) {
            methods.put(longKey, md);
            return;
        }
        MethodDescriptor composite = new MethodDescriptor(old, md);
        methods.put(longKey, composite);
    }

    
Creates a key for a method in a method cache.

/**
     * Creates a key for a method in a method cache.
     */
    private static String makeQualifiedMethodName(String name, String[] params) {
        StringBuilder sb = new StringBuilder(name);
        sb.append('=');
        for (int i = 0; i < params.length; i++) {
            sb.append(':');
            sb.append(params[i]);
        }
        return sb.toString();
    }

    private int getTargetDefaultEventIndex() {
        return defaultEventIndex;
    }

    private int getTargetDefaultPropertyIndex() {
        return defaultPropertyIndex;
    }

    private BeanDescriptor getTargetBeanDescriptor() {
        // Use explicit info, if available,
        if (explicitBeanInfo != null) {
            BeanDescriptor bd = explicitBeanInfo.getBeanDescriptor();
            if (bd != null) {
                return (bd);
            }
        }
        // OK, fabricate a default BeanDescriptor.
        return new BeanDescriptor(this.beanClass, findCustomizerClass(this.beanClass));
    }

    private static Class<?> findCustomizerClass(Class<?> type) {
        String name = type.getName() + "Customizer";
        try {
            type = ClassFinder.findClass(name, type.getClassLoader());
            // Each customizer should inherit java.awt.Component and implement java.beans.Customizer
            // according to the section 9.3 of JavaBeans&trade; specification
            if (Component.class.isAssignableFrom(type) && Customizer.class.isAssignableFrom(type)) {
                return type;
            }
        }
        catch (Exception exception) {
            // ignore any exceptions
        }
        return null;
    }

    private boolean isEventHandler(Method m) {
        // We assume that a method is an event handler if it has a single
        // argument, whose type inherit from java.util.Event.
        Type argTypes[] = m.getGenericParameterTypes();
        if (argTypes.length != 1) {
            return false;
        }
        return isSubclass(TypeResolver.erase(TypeResolver.resolveInClass(beanClass, argTypes[0])), EventObject.class);
    }

    //======================================================================
    // Package private support methods.
    //======================================================================

    
Internal support for finding a target methodName with a given
parameter list on a given class.

/**
     * Internal support for finding a target methodName with a given
     * parameter list on a given class.
     */
    private static Method internalFindMethod(Class<?> start, String methodName,
                                                 int argCount, Class<?> args[]) {
        // For overriden methods we need to find the most derived version.
        // So we start with the given class and walk up the superclass chain.
        for (Class<?> cl = start; cl != null; cl = cl.getSuperclass()) {
            for (Method method : ClassInfo.get(cl).getMethods()) {
                // make sure method signature matches.
                if (method.getName().equals(methodName)) {
                    Type[] params = method.getGenericParameterTypes();
                    if (params.length == argCount) {
                        if (args != null) {
                            boolean different = false;
                            if (argCount > 0) {
                                for (int j = 0; j < argCount; j++) {
                                    if (TypeResolver.erase(TypeResolver.resolveInClass(start, params[j])) != args[j]) {
                                        different = true;
                                        continue;
                                    }
                                }
                                if (different) {
                                    continue;
                                }
                            }
                        }
                        return method;
                    }
                }
            }
        }
        // Now check any inherited interfaces.  This is necessary both when
        // the argument class is itself an interface, and when the argument
        // class is an abstract class.
        Class<?>[] ifcs = start.getInterfaces();
        for (int i = 0 ; i < ifcs.length; i++) {
            // Note: The original implementation had both methods calling
            // the 3 arg method. This is preserved but perhaps it should
            // pass the args array instead of null.
            Method method = internalFindMethod(ifcs[i], methodName, argCount, null);
            if (method != null) {
                return method;
            }
        }
        return null;
    }

    
Find a target methodName on a given class.

/**
     * Find a target methodName on a given class.
     */
    static Method findMethod(Class<?> cls, String methodName, int argCount) {
        return findMethod(cls, methodName, argCount, null);
    }

    
Find a target methodName with specific parameter list on a given class.


Used in the contructors of the EventSetDescriptor,
PropertyDescriptor and the IndexedPropertyDescriptor.



Params:
  • cls – The Class object on which to retrieve the method.
  • methodName – Name of the method.
  • argCount – Number of arguments for the desired method.
  • args – Array of argument types for the method.
Returns:the method or null if not found
/**
     * Find a target methodName with specific parameter list on a given class.
     * <p>
     * Used in the contructors of the EventSetDescriptor,
     * PropertyDescriptor and the IndexedPropertyDescriptor.
     * <p>
     * @param cls The Class object on which to retrieve the method.
     * @param methodName Name of the method.
     * @param argCount Number of arguments for the desired method.
     * @param args Array of argument types for the method.
     * @return the method or null if not found
     */
    static Method findMethod(Class<?> cls, String methodName, int argCount,
                             Class<?>[] args) {
        if (methodName == null) {
            return null;
        }
        return internalFindMethod(cls, methodName, argCount, args);
    }

    
Return true if class a is either equivalent to class b, or
if class a is a subclass of class b, i.e. if a either "extends"
or "implements" b.
Note tht either or both "Class" objects may represent interfaces.

/**
     * Return true if class a is either equivalent to class b, or
     * if class a is a subclass of class b, i.e. if a either "extends"
     * or "implements" b.
     * Note tht either or both "Class" objects may represent interfaces.
     */
    static  boolean isSubclass(Class<?> a, Class<?> b) {
        // We rely on the fact that for any given java class or
        // primtitive type there is a unqiue Class object, so
        // we can use object equivalence in the comparisons.
        if (a == b) {
            return true;
        }
        if (a == null || b == null) {
            return false;
        }
        for (Class<?> x = a; x != null; x = x.getSuperclass()) {
            if (x == b) {
                return true;
            }
            if (b.isInterface()) {
                Class<?>[] interfaces = x.getInterfaces();
                for (int i = 0; i < interfaces.length; i++) {
                    if (isSubclass(interfaces[i], b)) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    
Try to create an instance of a named class.
First try the classloader of "sibling", then try the system
classloader then the class loader of the current Thread.

/**
     * Try to create an instance of a named class.
     * First try the classloader of "sibling", then try the system
     * classloader then the class loader of the current Thread.
     */
    @SuppressWarnings("deprecation")
    static Object instantiate(Class<?> sibling, String className)
                 throws InstantiationException, IllegalAccessException,
                        NoSuchMethodException, InvocationTargetException,
                                                ClassNotFoundException {
        // First check with sibling's classloader (if any).
        ClassLoader cl = sibling.getClassLoader();
        Class<?> cls = ClassFinder.findClass(className, cl);
        return cls.newInstance();
    }

} // end class Introspector

//===========================================================================


Package private implementation support class for Introspector's
internal use.


Mostly this is used as a placeholder for the descriptors.

/**
 * Package private implementation support class for Introspector's
 * internal use.
 * <p>
 * Mostly this is used as a placeholder for the descriptors.
 */

class GenericBeanInfo extends SimpleBeanInfo {

    private BeanDescriptor beanDescriptor;
    private EventSetDescriptor[] events;
    private int defaultEvent;
    private PropertyDescriptor[] properties;
    private int defaultProperty;
    private MethodDescriptor[] methods;
    private Reference<BeanInfo> targetBeanInfoRef;

    public GenericBeanInfo(BeanDescriptor beanDescriptor,
                EventSetDescriptor[] events, int defaultEvent,
                PropertyDescriptor[] properties, int defaultProperty,
                MethodDescriptor[] methods, BeanInfo targetBeanInfo) {
        this.beanDescriptor = beanDescriptor;
        this.events = events;
        this.defaultEvent = defaultEvent;
        this.properties = properties;
        this.defaultProperty = defaultProperty;
        this.methods = methods;
        this.targetBeanInfoRef = (targetBeanInfo != null)
                ? new SoftReference<>(targetBeanInfo)
                : null;
    }

    
Package-private dup constructor
This must isolate the new object from any changes to the old object.

/**
     * Package-private dup constructor
     * This must isolate the new object from any changes to the old object.
     */
    GenericBeanInfo(GenericBeanInfo old) {

        beanDescriptor = new BeanDescriptor(old.beanDescriptor);
        if (old.events != null) {
            int len = old.events.length;
            events = new EventSetDescriptor[len];
            for (int i = 0; i < len; i++) {
                events[i] = new EventSetDescriptor(old.events[i]);
            }
        }
        defaultEvent = old.defaultEvent;
        if (old.properties != null) {
            int len = old.properties.length;
            properties = new PropertyDescriptor[len];
            for (int i = 0; i < len; i++) {
                PropertyDescriptor oldp = old.properties[i];
                if (oldp instanceof IndexedPropertyDescriptor) {
                    properties[i] = new IndexedPropertyDescriptor(
                                        (IndexedPropertyDescriptor) oldp);
                } else {
                    properties[i] = new PropertyDescriptor(oldp);
                }
            }
        }
        defaultProperty = old.defaultProperty;
        if (old.methods != null) {
            int len = old.methods.length;
            methods = new MethodDescriptor[len];
            for (int i = 0; i < len; i++) {
                methods[i] = new MethodDescriptor(old.methods[i]);
            }
        }
        this.targetBeanInfoRef = old.targetBeanInfoRef;
    }

    public PropertyDescriptor[] getPropertyDescriptors() {
        return properties;
    }

    public int getDefaultPropertyIndex() {
        return defaultProperty;
    }

    public EventSetDescriptor[] getEventSetDescriptors() {
        return events;
    }

    public int getDefaultEventIndex() {
        return defaultEvent;
    }

    public MethodDescriptor[] getMethodDescriptors() {
        return methods;
    }

    public BeanDescriptor getBeanDescriptor() {
        return beanDescriptor;
    }

    public java.awt.Image getIcon(int iconKind) {
        BeanInfo targetBeanInfo = getTargetBeanInfo();
        if (targetBeanInfo != null) {
            return targetBeanInfo.getIcon(iconKind);
        }
        return super.getIcon(iconKind);
    }

    private BeanInfo getTargetBeanInfo() {
        if (this.targetBeanInfoRef == null) {
            return null;
        }
        BeanInfo targetBeanInfo = this.targetBeanInfoRef.get();
        if (targetBeanInfo == null) {
            targetBeanInfo = ThreadGroupContext.getContext().getBeanInfoFinder()
                    .find(this.beanDescriptor.getBeanClass());
            if (targetBeanInfo != null) {
                this.targetBeanInfoRef = new SoftReference<>(targetBeanInfo);
            }
        }
        return targetBeanInfo;
    }
}