The Commons Beanutils BeanUtilsBean.java source code
/*
* 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
*
* http://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.commons.beanutils;
import java.beans.IndexedPropertyDescriptor;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.commons.beanutils.expression.Resolver;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* <p>JavaBean property population methods.
*
* <p>This class provides implementations for the utility methods in
* {@link BeanUtils}.
* Different instances can be used to isolate caches between classloaders
* and to vary the value converters registered.</p>
*
* @author Craig R. McClanahan
* @author Ralph Schaer
* @author Chris Audley
* @author Rey Francois
* @author Gregor Rayman
* @version $Revision: 834031 $ $Date: 2009-11-09 12:26:52 +0000 (Mon, 09 Nov 2009) $
* @see BeanUtils
* @since 1.7
*/
public class BeanUtilsBean {
// ------------------------------------------------------ Private Class Variables
/**
* Contains <code>BeanUtilsBean instances indexed by context classloader.
*/
private static final ContextClassLoaderLocal
BEANS_BY_CLASSLOADER = new ContextClassLoaderLocal() {
// Creates the default instance used when the context classloader is unavailable
protected Object initialValue() {
return new BeanUtilsBean();
}
};
/**
* Gets the instance which provides the functionality for {@link BeanUtils}.
* This is a pseudo-singleton - an single instance is provided per (thread) context classloader.
* This mechanism provides isolation for web apps deployed in the same container.
*
* @return The (pseudo-singleton) BeanUtils bean instance
*/
public static BeanUtilsBean getInstance() {
return (BeanUtilsBean) BEANS_BY_CLASSLOADER.get();
}
/**
* Sets the instance which provides the functionality for {@link BeanUtils}.
* This is a pseudo-singleton - an single instance is provided per (thread) context classloader.
* This mechanism provides isolation for web apps deployed in the same container.
*
* @param newInstance The (pseudo-singleton) BeanUtils bean instance
*/
public static void setInstance(BeanUtilsBean newInstance) {
BEANS_BY_CLASSLOADER.set(newInstance);
}
// --------------------------------------------------------- Attributes
/**
* Logging for this instance
*/
private Log log = LogFactory.getLog(BeanUtils.class);
/** Used to perform conversions between object types when setting properties */
private ConvertUtilsBean convertUtilsBean;
/** Used to access properties*/
private PropertyUtilsBean propertyUtilsBean;
/** A reference to Throwable's initCause method, or null if it's not there in this JVM */
private static final Method INIT_CAUSE_METHOD = getInitCauseMethod();
// --------------------------------------------------------- Constuctors
/**
* <p>Constructs an instance using new property
* and conversion instances.</p>
*/
public BeanUtilsBean() {
this(new ConvertUtilsBean(), new PropertyUtilsBean());
}
/**
* <p>Constructs an instance using given conversion instances
* and new {@link PropertyUtilsBean} instance.</p>
*
* @param convertUtilsBean use this <code>ConvertUtilsBean
* to perform conversions from one object to another
*
* @since 1.8.0
*/
public BeanUtilsBean(ConvertUtilsBean convertUtilsBean) {
this(convertUtilsBean, new PropertyUtilsBean());
}
/**
* <p>Constructs an instance using given property and conversion instances.
*
* @param convertUtilsBean use this <code>ConvertUtilsBean
* to perform conversions from one object to another
* @param propertyUtilsBean use this <code>PropertyUtilsBean
* to access properties
*/
public BeanUtilsBean(
ConvertUtilsBean convertUtilsBean,
PropertyUtilsBean propertyUtilsBean) {
this.convertUtilsBean = convertUtilsBean;
this.propertyUtilsBean = propertyUtilsBean;
}
// --------------------------------------------------------- Public Methods
/**
* <p>Clone a bean based on the available property getters and setters,
* even if the bean class itself does not implement Cloneable.</p>
*
* <p>
* <strong>Note: this method creates a shallow clone.
* In other words, any objects referred to by the bean are shared with the clone
* rather than being cloned in turn.
* </p>
*
* @param bean Bean to be cloned
* @return the cloned bean
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InstantiationException if a new instance of the bean's
* class cannot be instantiated
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public Object cloneBean(Object bean)
throws IllegalAccessException, InstantiationException,
InvocationTargetException, NoSuchMethodException {
if (log.isDebugEnabled()) {
log.debug("Cloning bean: " + bean.getClass().getName());
}
Object newBean = null;
if (bean instanceof DynaBean) {
newBean = ((DynaBean) bean).getDynaClass().newInstance();
} else {
newBean = bean.getClass().newInstance();
}
getPropertyUtils().copyProperties(newBean, bean);
return (newBean);
}
/**
* <p>Copy property values from the origin bean to the destination bean
* for all cases where the property names are the same. For each
* property, a conversion is attempted as necessary. All combinations of
* standard JavaBeans and DynaBeans as origin and destination are
* supported. Properties that exist in the origin bean, but do not exist
* in the destination bean (or are read-only in the destination bean) are
* silently ignored.</p>
*
* <p>If the origin "bean" is actually a Map, it is assumed
* to contain String-valued <strong>simple property names as the keys, pointing at
* the corresponding property values that will be converted (if necessary)
* and set in the destination bean. <strong>Note that this method
* is intended to perform a "shallow copy" of the properties and so complex
* properties (for example, nested ones) will not be copied.</p>
*
* <p>This method differs from populate(), which
* was primarily designed for populating JavaBeans from the map of request
* parameters retrieved on an HTTP request, is that no scalar->indexed
* or indexed->scalar manipulations are performed. If the origin property
* is indexed, the destination property must be also.</p>
*
* <p>If you know that no type conversions are required, the
* <code>copyProperties() method in {@link PropertyUtils} will
* execute faster than this method.</p>
*
* <p>FIXME - Indexed and mapped properties that do not
* have getter and setter methods for the underlying array or Map are not
* copied by this method.</p>
*
* @param dest Destination bean whose properties are modified
* @param orig Origin bean whose properties are retrieved
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception IllegalArgumentException if the <code>dest or
* <code>orig argument is null or if the dest
* property type is different from the source type and the relevant
* converter has not been registered.
* @exception InvocationTargetException if the property accessor method
* throws an exception
*/
public void copyProperties(Object dest, Object orig)
throws IllegalAccessException, InvocationTargetException {
// Validate existence of the specified beans
if (dest == null) {
throw new IllegalArgumentException
("No destination bean specified");
}
if (orig == null) {
throw new IllegalArgumentException("No origin bean specified");
}
if (log.isDebugEnabled()) {
log.debug("BeanUtils.copyProperties(" + dest + ", " +
orig + ")");
}
// Copy the properties, converting as necessary
if (orig instanceof DynaBean) {
DynaProperty[] origDescriptors =
((DynaBean) orig).getDynaClass().getDynaProperties();
for (int i = 0; i < origDescriptors.length; i++) {
String name = origDescriptors[i].getName();
// Need to check isReadable() for WrapDynaBean
// (see Jira issue# BEANUTILS-61)
if (getPropertyUtils().isReadable(orig, name) &&
getPropertyUtils().isWriteable(dest, name)) {
Object value = ((DynaBean) orig).get(name);
copyProperty(dest, name, value);
}
}
} else if (orig instanceof Map) {
Iterator entries = ((Map) orig).entrySet().iterator();
while (entries.hasNext()) {
Map.Entry entry = (Map.Entry) entries.next();
String name = (String)entry.getKey();
if (getPropertyUtils().isWriteable(dest, name)) {
copyProperty(dest, name, entry.getValue());
}
}
} else /* if (orig is a standard JavaBean) */ {
PropertyDescriptor[] origDescriptors =
getPropertyUtils().getPropertyDescriptors(orig);
for (int i = 0; i < origDescriptors.length; i++) {
String name = origDescriptors[i].getName();
if ("class".equals(name)) {
continue; // No point in trying to set an object's class
}
if (getPropertyUtils().isReadable(orig, name) &&
getPropertyUtils().isWriteable(dest, name)) {
try {
Object value =
getPropertyUtils().getSimpleProperty(orig, name);
copyProperty(dest, name, value);
} catch (NoSuchMethodException e) {
// Should not happen
}
}
}
}
}
/**
* <p>Copy the specified property value to the specified destination bean,
* performing any type conversion that is required. If the specified
* bean does not have a property of the specified name, or the property
* is read only on the destination bean, return without
* doing anything. If you have custom destination property types, register
* {@link Converter}s for them by calling the <code>register()
* method of {@link ConvertUtils}.</p>
*
* <p>IMPLEMENTATION RESTRICTIONS:
* <ul>
* <li>Does not support destination properties that are indexed,
* but only an indexed setter (as opposed to an array setter)
* is available.</li>
* <li>Does not support destination properties that are mapped,
* but only a keyed setter (as opposed to a Map setter)
* is available.</li>
* <li>The desired property type of a mapped setter cannot be
* determined (since Maps support any data type), so no conversion
* will be performed.</li>
* </ul>
*
* @param bean Bean on which setting is to be performed
* @param name Property name (can be nested/indexed/mapped/combo)
* @param value Value to be set
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
*/
public void copyProperty(Object bean, String name, Object value)
throws IllegalAccessException, InvocationTargetException {
// Trace logging (if enabled)
if (log.isTraceEnabled()) {
StringBuffer sb = new StringBuffer(" copyProperty(");
sb.append(bean);
sb.append(", ");
sb.append(name);
sb.append(", ");
if (value == null) {
sb.append("<NULL>");
} else if (value instanceof String) {
sb.append((String) value);
} else if (value instanceof String[]) {
String[] values = (String[]) value;
sb.append('[');
for (int i = 0; i < values.length; i++) {
if (i > 0) {
sb.append(',');
}
sb.append(values[i]);
}
sb.append(']');
} else {
sb.append(value.toString());
}
sb.append(')');
log.trace(sb.toString());
}
// Resolve any nested expression to get the actual target bean
Object target = bean;
Resolver resolver = getPropertyUtils().getResolver();
while (resolver.hasNested(name)) {
try {
target = getPropertyUtils().getProperty(target, resolver.next(name));
name = resolver.remove(name);
} catch (NoSuchMethodException e) {
return; // Skip this property setter
}
}
if (log.isTraceEnabled()) {
log.trace(" Target bean = " + target);
log.trace(" Target name = " + name);
}
// Declare local variables we will require
String propName = resolver.getProperty(name); // Simple name of target property
Class type = null; // Java type of target property
int index = resolver.getIndex(name); // Indexed subscript value (if any)
String key = resolver.getKey(name); // Mapped key value (if any)
// Calculate the target property type
if (target instanceof DynaBean) {
DynaClass dynaClass = ((DynaBean) target).getDynaClass();
DynaProperty dynaProperty = dynaClass.getDynaProperty(propName);
if (dynaProperty == null) {
return; // Skip this property setter
}
type = dynaProperty.getType();
} else {
PropertyDescriptor descriptor = null;
try {
descriptor =
getPropertyUtils().getPropertyDescriptor(target, name);
if (descriptor == null) {
return; // Skip this property setter
}
} catch (NoSuchMethodException e) {
return; // Skip this property setter
}
type = descriptor.getPropertyType();
if (type == null) {
// Most likely an indexed setter on a POJB only
if (log.isTraceEnabled()) {
log.trace(" target type for property '" +
propName + "' is null, so skipping ths setter");
}
return;
}
}
if (log.isTraceEnabled()) {
log.trace(" target propName=" + propName + ", type=" +
type + ", index=" + index + ", key=" + key);
}
// Convert the specified value to the required type and store it
if (index >= 0) { // Destination must be indexed
value = convert(value, type.getComponentType());
try {
getPropertyUtils().setIndexedProperty(target, propName,
index, value);
} catch (NoSuchMethodException e) {
throw new InvocationTargetException
(e, "Cannot set " + propName);
}
} else if (key != null) { // Destination must be mapped
// Maps do not know what the preferred data type is,
// so perform no conversions at all
// FIXME - should we create or support a TypedMap?
try {
getPropertyUtils().setMappedProperty(target, propName,
key, value);
} catch (NoSuchMethodException e) {
throw new InvocationTargetException
(e, "Cannot set " + propName);
}
} else { // Destination must be simple
value = convert(value, type);
try {
getPropertyUtils().setSimpleProperty(target, propName, value);
} catch (NoSuchMethodException e) {
throw new InvocationTargetException
(e, "Cannot set " + propName);
}
}
}
/**
* <p>Return the entire set of properties for which the specified bean
* provides a read method. This map contains the to <code>String
* converted property values for all properties for which a read method
* is provided (i.e. where the getReadMethod() returns non-null).</p>
*
* <p>This map can be fed back to a call to
* <code>BeanUtils.populate() to reconsitute the same set of
* properties, modulo differences for read-only and write-only
* properties, but only if there are no indexed properties.</p>
*
* <p>Warning: if any of the bean property implementations
* contain (directly or indirectly) a call to this method then
* a stack overflow may result. For example:
* <code> * class MyBean
* {
* public Map getParameterMap()
* {
* BeanUtils.describe(this);
* }
* }
* </pre>
* will result in an infinite regression when <code>getParametersMap
* is called. It is recommended that such methods are given alternative
* names (for example, <code>parametersMap).
* </p>
* @param bean Bean whose properties are to be extracted
* @return Map of property descriptors
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public Map describe(Object bean)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
if (bean == null) {
// return (Collections.EMPTY_MAP);
return (new java.util.HashMap());
}
if (log.isDebugEnabled()) {
log.debug("Describing bean: " + bean.getClass().getName());
}
Map description = new HashMap();
if (bean instanceof DynaBean) {
DynaProperty[] descriptors =
((DynaBean) bean).getDynaClass().getDynaProperties();
for (int i = 0; i < descriptors.length; i++) {
String name = descriptors[i].getName();
description.put(name, getProperty(bean, name));
}
} else {
PropertyDescriptor[] descriptors =
getPropertyUtils().getPropertyDescriptors(bean);
Class clazz = bean.getClass();
for (int i = 0; i < descriptors.length; i++) {
String name = descriptors[i].getName();
if (getPropertyUtils().getReadMethod(clazz, descriptors[i]) != null) {
description.put(name, getProperty(bean, name));
}
}
}
return (description);
}
/**
* Return the value of the specified array property of the specified
* bean, as a String array.
*
* @param bean Bean whose property is to be extracted
* @param name Name of the property to be extracted
* @return The array property value
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String[] getArrayProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
Object value = getPropertyUtils().getProperty(bean, name);
if (value == null) {
return (null);
} else if (value instanceof Collection) {
ArrayList values = new ArrayList();
Iterator items = ((Collection) value).iterator();
while (items.hasNext()) {
Object item = items.next();
if (item == null) {
values.add((String) null);
} else {
// convert to string using convert utils
values.add(getConvertUtils().convert(item));
}
}
return ((String[]) values.toArray(new String[values.size()]));
} else if (value.getClass().isArray()) {
int n = Array.getLength(value);
String[] results = new String[n];
for (int i = 0; i < n; i++) {
Object item = Array.get(value, i);
if (item == null) {
results[i] = null;
} else {
// convert to string using convert utils
results[i] = getConvertUtils().convert(item);
}
}
return (results);
} else {
String[] results = new String[1];
results[0] = getConvertUtils().convert(value);
return (results);
}
}
/**
* Return the value of the specified indexed property of the specified
* bean, as a String. The zero-relative index of the
* required value must be included (in square brackets) as a suffix to
* the property name, or <code>IllegalArgumentException will be
* thrown.
*
* @param bean Bean whose property is to be extracted
* @param name <code>propertyname[index] of the property value
* to be extracted
* @return The indexed property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String getIndexedProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
Object value = getPropertyUtils().getIndexedProperty(bean, name);
return (getConvertUtils().convert(value));
}
/**
* Return the value of the specified indexed property of the specified
* bean, as a String. The index is specified as a method parameter and
* must *not* be included in the property name expression
*
* @param bean Bean whose property is to be extracted
* @param name Simple property name of the property value to be extracted
* @param index Index of the property value to be extracted
* @return The indexed property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String getIndexedProperty(Object bean,
String name, int index)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
Object value = getPropertyUtils().getIndexedProperty(bean, name, index);
return (getConvertUtils().convert(value));
}
/**
* Return the value of the specified indexed property of the specified
* bean, as a String. The String-valued key of the required value
* must be included (in parentheses) as a suffix to
* the property name, or <code>IllegalArgumentException will be
* thrown.
*
* @param bean Bean whose property is to be extracted
* @param name <code>propertyname(index) of the property value
* to be extracted
* @return The mapped property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String getMappedProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
Object value = getPropertyUtils().getMappedProperty(bean, name);
return (getConvertUtils().convert(value));
}
/**
* Return the value of the specified mapped property of the specified
* bean, as a String. The key is specified as a method parameter and
* must *not* be included in the property name expression
*
* @param bean Bean whose property is to be extracted
* @param name Simple property name of the property value to be extracted
* @param key Lookup key of the property value to be extracted
* @return The mapped property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String getMappedProperty(Object bean,
String name, String key)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
Object value = getPropertyUtils().getMappedProperty(bean, name, key);
return (getConvertUtils().convert(value));
}
/**
* Return the value of the (possibly nested) property of the specified
* name, for the specified bean, as a String.
*
* @param bean Bean whose property is to be extracted
* @param name Possibly nested name of the property to be extracted
* @return The nested property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception IllegalArgumentException if a nested reference to a
* property returns null
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String getNestedProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
Object value = getPropertyUtils().getNestedProperty(bean, name);
return (getConvertUtils().convert(value));
}
/**
* Return the value of the specified property of the specified bean,
* no matter which property reference format is used, as a String.
*
* @param bean Bean whose property is to be extracted
* @param name Possibly indexed and/or nested name of the property
* to be extracted
* @return The property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String getProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
return (getNestedProperty(bean, name));
}
/**
* Return the value of the specified simple property of the specified
* bean, converted to a String.
*
* @param bean Bean whose property is to be extracted
* @param name Name of the property to be extracted
* @return The property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
* @exception NoSuchMethodException if an accessor method for this
* property cannot be found
*/
public String getSimpleProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {
Object value = getPropertyUtils().getSimpleProperty(bean, name);
return (getConvertUtils().convert(value));
}
/**
* <p>Populate the JavaBeans properties of the specified bean, based on
* the specified name/value pairs. This method uses Java reflection APIs
* to identify corresponding "property setter" method names, and deals
* with setter arguments of type <code>String, boolean,
* <code>int, long, float, and
* <code>double. In addition, array setters for these types (or the
* corresponding primitive types) can also be identified.</p>
*
* <p>The particular setter method to be called for each property is
* determined using the usual JavaBeans introspection mechanisms. Thus,
* you may identify custom setter methods using a BeanInfo class that is
* associated with the class of the bean itself. If no such BeanInfo
* class is available, the standard method name conversion ("set" plus
* the capitalized name of the property in question) is used.</p>
*
* <p>NOTE: It is contrary to the JavaBeans Specification
* to have more than one setter method (with different argument
* signatures) for the same property.</p>
*
* <p>WARNING - The logic of this method is customized
* for extracting String-based request parameters from an HTTP request.
* It is probably not what you want for general property copying with
* type conversion. For that purpose, check out the
* <code>copyProperties() method instead.
*
* @param bean JavaBean whose properties are being populated
* @param properties Map keyed by property name, with the
* corresponding (String or String[]) value(s) to be set
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
*/
public void populate(Object bean, Map properties)
throws IllegalAccessException, InvocationTargetException {
// Do nothing unless both arguments have been specified
if ((bean == null) || (properties == null)) {
return;
}
if (log.isDebugEnabled()) {
log.debug("BeanUtils.populate(" + bean + ", " +
properties + ")");
}
// Loop through the property name/value pairs to be set
Iterator entries = properties.entrySet().iterator();
while (entries.hasNext()) {
// Identify the property name and value(s) to be assigned
Map.Entry entry = (Map.Entry)entries.next();
String name = (String) entry.getKey();
if (name == null) {
continue;
}
// Perform the assignment for this property
setProperty(bean, name, entry.getValue());
}
}
/**
* <p>Set the specified property value, performing type conversions as
* required to conform to the type of the destination property.</p>
*
* <p>If the property is read only then the method returns
* without throwing an exception.</p>
*
* <p>If null is passed into a property expecting a primitive value,
* then this will be converted as if it were a <code>null string.
*
* <p>WARNING - The logic of this method is customized
* to meet the needs of <code>populate(), and is probably not what
* you want for general property copying with type conversion. For that
* purpose, check out the <code>copyProperty() method instead.
*
* <p>WARNING - PLEASE do not modify the behavior of this
* method without consulting with the Struts developer community. There
* are some subtleties to its functionality that are not documented in the
* Javadoc description above, yet are vital to the way that Struts utilizes
* this method.</p>
*
* @param bean Bean on which setting is to be performed
* @param name Property name (can be nested/indexed/mapped/combo)
* @param value Value to be set
*
* @exception IllegalAccessException if the caller does not have
* access to the property accessor method
* @exception InvocationTargetException if the property accessor method
* throws an exception
*/
public void setProperty(Object bean, String name, Object value)
throws IllegalAccessException, InvocationTargetException {
// Trace logging (if enabled)
if (log.isTraceEnabled()) {
StringBuffer sb = new StringBuffer(" setProperty(");
sb.append(bean);
sb.append(", ");
sb.append(name);
sb.append(", ");
if (value == null) {
sb.append("<NULL>");
} else if (value instanceof String) {
sb.append((String) value);
} else if (value instanceof String[]) {
String[] values = (String[]) value;
sb.append('[');
for (int i = 0; i < values.length; i++) {
if (i > 0) {
sb.append(',');
}
sb.append(values[i]);
}
sb.append(']');
} else {
sb.append(value.toString());
}
sb.append(')');
log.trace(sb.toString());
}
// Resolve any nested expression to get the actual target bean
Object target = bean;
Resolver resolver = getPropertyUtils().getResolver();
while (resolver.hasNested(name)) {
try {
target = getPropertyUtils().getProperty(target, resolver.next(name));
name = resolver.remove(name);
} catch (NoSuchMethodException e) {
return; // Skip this property setter
}
}
if (log.isTraceEnabled()) {
log.trace(" Target bean = " + target);
log.trace(" Target name = " + name);
}
// Declare local variables we will require
String propName = resolver.getProperty(name); // Simple name of target property
Class type = null; // Java type of target property
int index = resolver.getIndex(name); // Indexed subscript value (if any)
String key = resolver.getKey(name); // Mapped key value (if any)
// Calculate the property type
if (target instanceof DynaBean) {
DynaClass dynaClass = ((DynaBean) target).getDynaClass();
DynaProperty dynaProperty = dynaClass.getDynaProperty(propName);
if (dynaProperty == null) {
return; // Skip this property setter
}
type = dynaProperty.getType();
} else if (target instanceof Map) {
type = Object.class;
} else if (target != null && target.getClass().isArray() && index >= 0) {
type = Array.get(target, index).getClass();
} else {
PropertyDescriptor descriptor = null;
try {
descriptor =
getPropertyUtils().getPropertyDescriptor(target, name);
if (descriptor == null) {
return; // Skip this property setter
}
} catch (NoSuchMethodException e) {
return; // Skip this property setter
}
if (descriptor instanceof MappedPropertyDescriptor) {
if (((MappedPropertyDescriptor) descriptor).getMappedWriteMethod() == null) {
if (log.isDebugEnabled()) {
log.debug("Skipping read-only property");
}
return; // Read-only, skip this property setter
}
type = ((MappedPropertyDescriptor) descriptor).
getMappedPropertyType();
} else if (index >= 0 && descriptor instanceof IndexedPropertyDescriptor) {
if (((IndexedPropertyDescriptor) descriptor).getIndexedWriteMethod() == null) {
if (log.isDebugEnabled()) {
log.debug("Skipping read-only property");
}
return; // Read-only, skip this property setter
}
type = ((IndexedPropertyDescriptor) descriptor).
getIndexedPropertyType();
} else if (key != null) {
if (descriptor.getReadMethod() == null) {
if (log.isDebugEnabled()) {
log.debug("Skipping read-only property");
}
return; // Read-only, skip this property setter
}
type = (value == null) ? Object.class : value.getClass();
} else {
if (descriptor.getWriteMethod() == null) {
if (log.isDebugEnabled()) {
log.debug("Skipping read-only property");
}
return; // Read-only, skip this property setter
}
type = descriptor.getPropertyType();
}
}
// Convert the specified value to the required type
Object newValue = null;
if (type.isArray() && (index < 0)) { // Scalar value into array
if (value == null) {
String[] values = new String[1];
values[0] = null;
newValue = getConvertUtils().convert(values, type);
} else if (value instanceof String) {
newValue = getConvertUtils().convert(value, type);
} else if (value instanceof String[]) {
newValue = getConvertUtils().convert((String[]) value, type);
} else {
newValue = convert(value, type);
}
} else if (type.isArray()) { // Indexed value into array
if (value instanceof String || value == null) {
newValue = getConvertUtils().convert((String) value,
type.getComponentType());
} else if (value instanceof String[]) {
newValue = getConvertUtils().convert(((String[]) value)[0],
type.getComponentType());
} else {
newValue = convert(value, type.getComponentType());
}
} else { // Value into scalar
if (value instanceof String) {
newValue = getConvertUtils().convert((String) value, type);
} else if (value instanceof String[]) {
newValue = getConvertUtils().convert(((String[]) value)[0],
type);
} else {
newValue = convert(value, type);
}
}
// Invoke the setter method
try {
getPropertyUtils().setProperty(target, name, newValue);
} catch (NoSuchMethodException e) {
throw new InvocationTargetException
(e, "Cannot set " + propName);
}
}
/**
* Gets the <code>ConvertUtilsBean instance used to perform the conversions.
*
* @return The ConvertUtils bean instance
*/
public ConvertUtilsBean getConvertUtils() {
return convertUtilsBean;
}
/**
* Gets the <code>PropertyUtilsBean instance used to access properties.
*
* @return The ConvertUtils bean instance
*/
public PropertyUtilsBean getPropertyUtils() {
return propertyUtilsBean;
}
/**
* If we're running on JDK 1.4 or later, initialize the cause for the given throwable.
*
* @param throwable The throwable.
* @param cause The cause of the throwable.
* @return true if the cause was initialized, otherwise false.
* @since 1.8.0
*/
public boolean initCause(Throwable throwable, Throwable cause) {
if (INIT_CAUSE_METHOD != null && cause != null) {
try {
INIT_CAUSE_METHOD.invoke(throwable, new Object[] { cause });
return true;
} catch (Throwable e) {
return false; // can't initialize cause
}
}
return false;
}
/**
* <p>Convert the value to an object of the specified class (if
* possible).</p>
*
* @param value Value to be converted (may be null)
* @param type Class of the value to be converted to
* @return The converted value
*
* @exception ConversionException if thrown by an underlying Converter
* @since 1.8.0
*/
protected Object convert(Object value, Class type) {
Converter converter = getConvertUtils().lookup(type);
if (converter != null) {
log.trace(" USING CONVERTER " + converter);
return converter.convert(type, value);
} else {
return value;
}
}
/**
* Returns a <code>Method allowing access to
* {@link Throwable#initCause(Throwable)} method of {@link Throwable},
* or <code>null if the method
* does not exist.
*
* @return A <code>Method for Throwable.initCause, or
* <code>null if unavailable.
*/
private static Method getInitCauseMethod() {
try {
Class[] paramsClasses = new Class[] { Throwable.class };
return Throwable.class.getMethod("initCause", paramsClasses);
} catch (NoSuchMethodException e) {
Log log = LogFactory.getLog(BeanUtils.class);
if (log.isWarnEnabled()) {
log.warn("Throwable does not have initCause() method in JDK 1.3");
}
return null;
} catch (Throwable e) {
Log log = LogFactory.getLog(BeanUtils.class);
if (log.isWarnEnabled()) {
log.warn("Error getting the Throwable initCause() method", e);
}
return null;
}
}
}
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