ch.qos.logback/logback-core/1.2.3 : ch/qos/logback/core/joran/util/PropertySetter.java

PropertySetter
http://logback.qos.ch/logback-core: logback-core module (QOS.ch)
Ceki Gulcu
Joern Huxhorn
Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
// Contributors:  Georg Lundesgaard
package ch.qos.logback.core.joran.util;

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

import ch.qos.logback.core.joran.spi.DefaultClass;
import ch.qos.logback.core.joran.spi.DefaultNestedComponentRegistry;
import ch.qos.logback.core.joran.util.beans.BeanDescription;
import ch.qos.logback.core.joran.util.beans.BeanDescriptionCache;
import ch.qos.logback.core.joran.util.beans.BeanUtil;
import ch.qos.logback.core.spi.ContextAwareBase;
import ch.qos.logback.core.util.AggregationType;
import ch.qos.logback.core.util.PropertySetterException;

General purpose Object property setter. Clients repeatedly invokes setProperty(name,value) in order to invoke setters on the Object specified in the constructor. This class relies on the JavaBeans Introspector to analyze the given Object Class using reflection. 
Usage:
PropertySetter ps = new PropertySetter(anObject);
ps.set("name", "Joe");
ps.set("age", "32");
ps.set("isMale", "true");
 will cause the invocations anObject.setName("Joe"), anObject.setAge(32), and setMale(true) if such methods exist with those signatures. Otherwise an IntrospectionException are thrown. 
Author: Anders Kristensen, Ceki Gulcu/**
 * General purpose Object property setter. Clients repeatedly invokes
 * {@link #setProperty setProperty(name,value)} in order to invoke setters on
 * the Object specified in the constructor. This class relies on the JavaBeans
 * {@link Introspector} to analyze the given Object Class using reflection.
 *
 * <p>
 * Usage:
 *
 * <pre>
 * PropertySetter ps = new PropertySetter(anObject);
 * ps.set(&quot;name&quot;, &quot;Joe&quot;);
 * ps.set(&quot;age&quot;, &quot;32&quot;);
 * ps.set(&quot;isMale&quot;, &quot;true&quot;);
 * </pre>
 *
 * will cause the invocations anObject.setName("Joe"), anObject.setAge(32), and
 * setMale(true) if such methods exist with those signatures. Otherwise an
 * {@link IntrospectionException} are thrown.
 *
 * @author Anders Kristensen
 * @author Ceki Gulcu
 */
public class PropertySetter extends ContextAwareBase {

    protected final Object obj;
    protected final Class<?> objClass;
    protected final BeanDescription beanDescription;

    Create a new PropertySetter for the specified Object. This is done in preparation for invoking setProperty one or more times. 
Params: obj – 
         the object for which to set properties/**
     * Create a new PropertySetter for the specified Object. This is done in
     * preparation for invoking {@link #setProperty} one or more times.
     *
     * @param obj
     *          the object for which to set properties
     */
    public PropertySetter(BeanDescriptionCache beanDescriptionCache, Object obj) {
        this.obj = obj;
        this.objClass = obj.getClass();
        this.beanDescription = beanDescriptionCache.getBeanDescription(objClass);
    }

    Set a property on this PropertySetter's Object. If successful, this method
will invoke a setter method on the underlying Object. The setter is the one
for the specified property name and the value is determined partly from the
setter argument type and partly from the value specified in the call to
this method.

If the setter expects a String no conversion is necessary. If it expects an
int, then an attempt is made to convert 'value' to an int using new
Integer(value). If the setter expects a boolean, the conversion is by new
Boolean(value).
Params: name – 
         name of the property
value – 
         String value of the property/**
     * Set a property on this PropertySetter's Object. If successful, this method
     * will invoke a setter method on the underlying Object. The setter is the one
     * for the specified property name and the value is determined partly from the
     * setter argument type and partly from the value specified in the call to
     * this method.
     *
     * <p>
     * If the setter expects a String no conversion is necessary. If it expects an
     * int, then an attempt is made to convert 'value' to an int using new
     * Integer(value). If the setter expects a boolean, the conversion is by new
     * Boolean(value).
     *
     * @param name
     *          name of the property
     * @param value
     *          String value of the property
     */
    public void setProperty(String name, String value) {
        if (value == null) {
            return;
        }
        Method setter = findSetterMethod(name);
        if (setter == null) {
            addWarn("No setter for property [" + name + "] in " + objClass.getName() + ".");
        } else {
            try {
                setProperty(setter, name, value);
            } catch (PropertySetterException ex) {
                addWarn("Failed to set property [" + name + "] to value \"" + value + "\". ", ex);
            }
        }
    }

    Set the named property given a PropertyDescriptor. 
Params: prop – 
         A PropertyDescriptor describing the characteristics of the
         property to set.
name – 
         The named of the property to set.
value – 
         The value of the property./**
     * Set the named property given a {@link PropertyDescriptor}.
     *
     * @param prop
     *          A PropertyDescriptor describing the characteristics of the
     *          property to set.
     * @param name
     *          The named of the property to set.
     * @param value
     *          The value of the property.
     */
    private void setProperty(Method setter, String name, String value) throws PropertySetterException {
        Class<?>[] paramTypes = setter.getParameterTypes();

        Object arg;

        try {
            arg = StringToObjectConverter.convertArg(this, value, paramTypes[0]);
        } catch (Throwable t) {
            throw new PropertySetterException("Conversion to type [" + paramTypes[0] + "] failed. ", t);
        }

        if (arg == null) {
            throw new PropertySetterException("Conversion to type [" + paramTypes[0] + "] failed.");
        }
        try {
            setter.invoke(obj, arg);
        } catch (Exception ex) {
            throw new PropertySetterException(ex);
        }
    }

    public AggregationType computeAggregationType(String name) {
        String cName = capitalizeFirstLetter(name);

        Method addMethod = findAdderMethod(cName);

        if (addMethod != null) {
            AggregationType type = computeRawAggregationType(addMethod);
            switch (type) {
            case NOT_FOUND:
                return AggregationType.NOT_FOUND;
            case AS_BASIC_PROPERTY:
                return AggregationType.AS_BASIC_PROPERTY_COLLECTION;

            case AS_COMPLEX_PROPERTY:
                return AggregationType.AS_COMPLEX_PROPERTY_COLLECTION;
            case AS_BASIC_PROPERTY_COLLECTION:
            case AS_COMPLEX_PROPERTY_COLLECTION:
                addError("Unexpected AggregationType " + type);
            }
        }

        Method setter = findSetterMethod(name);
        if (setter != null) {
            return computeRawAggregationType(setter);
        } else {
            // we have failed
            return AggregationType.NOT_FOUND;
        }
    }

    private Method findAdderMethod(String name) {
        String propertyName = BeanUtil.toLowerCamelCase(name);
        return beanDescription.getAdder(propertyName);
    }

    private Method findSetterMethod(String name) {
        String propertyName = BeanUtil.toLowerCamelCase(name);
        return beanDescription.getSetter(propertyName);
    }

    private Class<?> getParameterClassForMethod(Method method) {
        if (method == null) {
            return null;
        }
        Class<?>[] classArray = method.getParameterTypes();
        if (classArray.length != 1) {
            return null;
        } else {
            return classArray[0];
        }
    }

    private AggregationType computeRawAggregationType(Method method) {
        Class<?> parameterClass = getParameterClassForMethod(method);
        if (parameterClass == null) {
            return AggregationType.NOT_FOUND;
        }
        if (StringToObjectConverter.canBeBuiltFromSimpleString(parameterClass)) {
            return AggregationType.AS_BASIC_PROPERTY;
        } else {
            return AggregationType.AS_COMPLEX_PROPERTY;
        }
    }

    Can the given clazz instantiable with certainty?
Params: clazz – 
         The class to test for instantiability
Returns: true if clazz can be instantiated, and false otherwise./**
     * Can the given clazz instantiable with certainty?
     *
     * @param clazz
     *          The class to test for instantiability
     * @return true if clazz can be instantiated, and false otherwise.
     */
    private boolean isUnequivocallyInstantiable(Class<?> clazz) {
        if (clazz.isInterface()) {
            return false;
        }
        // checking for constructors would be more elegant, but in
        // classes without any declared constructors, Class.getConstructor()
        // returns null.
        Object o;
        try {
            o = clazz.newInstance();
            if (o != null) {
                return true;
            } else {
                return false;
            }
        } catch (InstantiationException e) {
            return false;
        } catch (IllegalAccessException e) {
            return false;
        }
    }

    public Class<?> getObjClass() {
        return objClass;
    }

    public void addComplexProperty(String name, Object complexProperty) {
        Method adderMethod = findAdderMethod(name);
        // first let us use the addXXX method
        if (adderMethod != null) {
            Class<?>[] paramTypes = adderMethod.getParameterTypes();
            if (!isSanityCheckSuccessful(name, adderMethod, paramTypes, complexProperty)) {
                return;
            }
            invokeMethodWithSingleParameterOnThisObject(adderMethod, complexProperty);
        } else {
            addError("Could not find method [" + "add" + name + "] in class [" + objClass.getName() + "].");
        }
    }

    void invokeMethodWithSingleParameterOnThisObject(Method method, Object parameter) {
        Class<?> ccc = parameter.getClass();
        try {
            method.invoke(this.obj, parameter);
        } catch (Exception e) {
            addError("Could not invoke method " + method.getName() + " in class " + obj.getClass().getName() + " with parameter of type " + ccc.getName(), e);
        }
    }

    public void addBasicProperty(String name, String strValue) {

        if (strValue == null) {
            return;
        }

        name = capitalizeFirstLetter(name);
        Method adderMethod = findAdderMethod(name);

        if (adderMethod == null) {
            addError("No adder for property [" + name + "].");
            return;
        }

        Class<?>[] paramTypes = adderMethod.getParameterTypes();
        isSanityCheckSuccessful(name, adderMethod, paramTypes, strValue);

        Object arg;
        try {
            arg = StringToObjectConverter.convertArg(this, strValue, paramTypes[0]);
        } catch (Throwable t) {
            addError("Conversion to type [" + paramTypes[0] + "] failed. ", t);
            return;
        }
        if (arg != null) {
            invokeMethodWithSingleParameterOnThisObject(adderMethod, strValue);
        }
    }

    public void setComplexProperty(String name, Object complexProperty) {
        Method setter = findSetterMethod(name);

        if (setter == null) {
            addWarn("Not setter method for property [" + name + "] in " + obj.getClass().getName());

            return;
        }

        Class<?>[] paramTypes = setter.getParameterTypes();

        if (!isSanityCheckSuccessful(name, setter, paramTypes, complexProperty)) {
            return;
        }
        try {
            invokeMethodWithSingleParameterOnThisObject(setter, complexProperty);

        } catch (Exception e) {
            addError("Could not set component " + obj + " for parent component " + obj, e);
        }
    }

    private boolean isSanityCheckSuccessful(String name, Method method, Class<?>[] params, Object complexProperty) {
        Class<?> ccc = complexProperty.getClass();
        if (params.length != 1) {
            addError("Wrong number of parameters in setter method for property [" + name + "] in " + obj.getClass().getName());

            return false;
        }

        if (!params[0].isAssignableFrom(complexProperty.getClass())) {
            addError("A \"" + ccc.getName() + "\" object is not assignable to a \"" + params[0].getName() + "\" variable.");
            addError("The class \"" + params[0].getName() + "\" was loaded by ");
            addError("[" + params[0].getClassLoader() + "] whereas object of type ");
            addError("\"" + ccc.getName() + "\" was loaded by [" + ccc.getClassLoader() + "].");
            return false;
        }

        return true;
    }

    private String capitalizeFirstLetter(String name) {
        return name.substring(0, 1).toUpperCase() + name.substring(1);
    }

    public Object getObj() {
        return obj;
    }

    Method getRelevantMethod(String name, AggregationType aggregationType) {
        Method relevantMethod;
        if (aggregationType == AggregationType.AS_COMPLEX_PROPERTY_COLLECTION) {
            relevantMethod = findAdderMethod(name);
        } else if (aggregationType == AggregationType.AS_COMPLEX_PROPERTY) {
            relevantMethod = findSetterMethod(name);
        } else {
            throw new IllegalStateException(aggregationType + " not allowed here");
        }
        return relevantMethod;
    }

    <T extends Annotation> T getAnnotation(String name, Class<T> annonationClass, Method relevantMethod) {

        if (relevantMethod != null) {
            return relevantMethod.getAnnotation(annonationClass);
        } else {
            return null;
        }
    }

    Class<?> getDefaultClassNameByAnnonation(String name, Method relevantMethod) {
        DefaultClass defaultClassAnnon = getAnnotation(name, DefaultClass.class, relevantMethod);
        if (defaultClassAnnon != null) {
            return defaultClassAnnon.value();
        }
        return null;
    }

    Class<?> getByConcreteType(String name, Method relevantMethod) {

        Class<?> paramType = getParameterClassForMethod(relevantMethod);
        if (paramType == null) {
            return null;
        }

        boolean isUnequivocallyInstantiable = isUnequivocallyInstantiable(paramType);
        if (isUnequivocallyInstantiable) {
            return paramType;
        } else {
            return null;
        }

    }

    public Class<?> getClassNameViaImplicitRules(String name, AggregationType aggregationType, DefaultNestedComponentRegistry registry) {

        Class<?> registryResult = registry.findDefaultComponentType(obj.getClass(), name);
        if (registryResult != null) {
            return registryResult;
        }
        // find the relevant method for the given property name and aggregationType
        Method relevantMethod = getRelevantMethod(name, aggregationType);
        if (relevantMethod == null) {
            return null;
        }
        Class<?> byAnnotation = getDefaultClassNameByAnnonation(name, relevantMethod);
        if (byAnnotation != null) {
            return byAnnotation;
        }
        return getByConcreteType(name, relevantMethod);
    }

}
Params:	clazz – The class to test for instantiability
Returns:	true if clazz can be instantiated, and false otherwise.
/

ch.qos.logback/ logback-core/ 1.2.3/ ch/qos/logback/core/joran/util/PropertySetter.java
