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/* * Copyright 2002,2004 The Apache Software Foundation. * * Licensed 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.struts.faces.application; import java.util.Map; import javax.faces.el.PropertyNotFoundException; import javax.faces.el.PropertyResolver; import org.apache.commons.beanutils.DynaBean; import org.apache.commons.beanutils.DynaProperty; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.struts.action.DynaActionForm; /** * <p>Custom <code>PropertyResolver</code> implementation that adds support * for <code>DynaBean</code> property access to the facilities of the default * <code>PropertyResolver</code> provided by JavaServer Faces.</p> * * <p>This class implements the following specific rules:</p> * <ul> * <li>Indexed variants of each call are directly passed through to the * <code>PropertyResolver</code> instance that we are wrapping.</li> * <li>If the specified base object is an instance of * <code>DynaActionForm</code>, and the requested property name is * <code>map</code>, maintain compatibility with the way that JSP and * JSTL expressions can access this property: * <ul> * <li><code>getValue()</code> will return the result of calling * <code>getMap()</code> on the base object.</li> * <li><code>setValue()</code> will throw an exception, because the * map of property values is a read-only property of the * <code>DynaActionForm</code> class.</li> * <li><code>isReadOnly()</code> returns <code>true</code>.</li> * <li><code>getType()</code> returns the <code>Class</code> object * for <code>java.util.Map</code>.</li> * </ul></li> * <li>If the specified base object is an instance of * <code>DynaBean</code>, provide access to its named properties * as follows: * <ul> * <li><code>getValue()</code> will return the result of calling * <code>get()</code> on the base object.</li> * <li><code>setValue()</code> will call <code>set()</code> * on the base object.</li> * <li><code>isReadOnly()</code> returns <code>false</code> (because * the DynaBean APIs provide no mechanism to make this determination, * but most implementations will provide mutable properties).</li> * <li><code>getType()</code> returns the <code>Class</code> object * for the underlying dynamic property.</li> * </ul></li> * <li>Named variant calls with any other type of base object are * passed through to the <code>PropertyResolver</code> that we * are wrapping.</li> * </ul> * * @version $Rev: 54934 $ $Date: 2004-10-16 18:07:50 +0100 (Sat, 16 Oct 2004) $ */ public class PropertyResolverImpl extends PropertyResolver { // ------------------------------------------------------------ Constructor /** * <p>Construct a new <code>PropertyResolver</code> instance, wrapping the * specified instance using the Decorator pattern such that this class need * implement only the new functionality it supports, and not need to * re-implement the basic facilities. * * @param resolver The original resolver to be wrapped * * @exception NullPointerException if <code>resolver</code> * is <code>null</code> */ public PropertyResolverImpl(PropertyResolver resolver) { if (resolver == null) { throw new NullPointerException(); } if (log.isDebugEnabled()) { log.debug("Creating new instance, wrapping resolver " + resolver); } this.resolver = resolver; } // ----------------------------------------------------- Instance Variables /** * <p>The <code>Log</code> instance for this class.</p> */ private static final Log log = LogFactory.getLog(PropertyResolverImpl.class); /** * <p>The <code>PropertyResolver</code> instance that we are wrapping, * which will be used to perform operations on beans that are not * recognized by this class.</p> */ private PropertyResolver resolver = null; // ----------------------------------------------- PropertyResolver Methods /** * <p>Return the value of the property with the specified name from * the specified base object.</p> * * @param base The base object whose property value is to be returned * @param name Name of the property to be returned * * @exception NullPointerException if <code>base</code> or * <code>name</code> is <code>null</code> * @exception PropertyNotFoundException if the specified property name * does not exist, or is not readable */ public Object getValue(Object base, Object name) throws PropertyNotFoundException { if ((base == null) || (name == null)) { throw new NullPointerException(); } else if ((base instanceof DynaActionForm) && ("map".equals(name))) { if (log.isTraceEnabled()) { log.trace("Returning property map for DynaActionForm " + base + "'"); } return (((DynaActionForm) base).getMap()); } else if (base instanceof DynaBean) { if (getDynaProperty((DynaBean) base, name.toString()) == null) { throw new PropertyNotFoundException(name.toString()); } Object value = ((DynaBean) base).get(name.toString()); if (log.isTraceEnabled()) { log.trace("Returning dynamic property '" + name + "' for DynaBean '" + base + "' value '" + value + "'"); } return (value); } else { Object value = resolver.getValue(base, name); if (log.isTraceEnabled()) { log.trace( "Delegating get of property '" + name + "' for bean '" + base + "' value '" + value + "'"); } return (value); } } /** * <p>Return the value at the specified index of the specified * base object.</p> * * @param base The base object whose property value is to be returned * @param index Index of the value to return * * @exception IndexOutOfBoundsException if thrown by the underlying * access to the base object * @exception NullPointerException if <code>base</code> * is <code>null</code> * @exception PropertyNotFoundException if some other exception occurs */ public Object getValue(Object base, int index) throws PropertyNotFoundException { return (resolver.getValue(base, index)); } /** * <p>Set the specified value of the property with the specified name on * the specified base object.</p> * * @param base The base object whose property value is to be set * @param name Name of the property to be set * @param value Value of the property to be set * * @exception NullPointerException if <code>base</code> or * <code>name</code> is <code>null</code> * @exception PropertyNotFoundException if the specified property name * does not exist, or is not writeable */ public void setValue(Object base, Object name, Object value) throws PropertyNotFoundException { if ((base == null) || (name == null)) { throw new NullPointerException(); } else if ((base instanceof DynaActionForm) && ("map".equals(name))) { throw new PropertyNotFoundException(name.toString()); } else if (base instanceof DynaBean) { if (log.isTraceEnabled()) { log.trace("setting dynamic property '" + name + "' for DynaBean '" + base + "' to '" + value + "'"); } if (getDynaProperty((DynaBean) base, name.toString()) == null) { throw new PropertyNotFoundException(name.toString()); } ((DynaBean) base).set(name.toString(), value); } else { if (log.isTraceEnabled()) { log.trace("Delegating set of property '" + name + "' for bean '" + base + "' to value '" + value + "'"); } resolver.setValue(base, name, value); } } /** * <p>Set the value at the specified index of the specified * base object.</p> * * @param base The base object whose property value is to be set * @param index Index of the value to set * @param value Value to be set * * @exception IndexOutOfBoundsException if thrown by the underlying * access to the base object * @exception NullPointerException if <code>base</code> * is <code>null</code> * @exception PropertyNotFoundException if some other exception occurs */ public void setValue(Object base, int index, Object value) throws PropertyNotFoundException { resolver.setValue(base, index, value); } /** * <p>Return <code>true</code> if the specified property of the specified * base object is known to be immutable; otherwise, return * <code>false</code>.</p> * * @param base The base object whose property is to analyzed * @param name Name of the property to be analyzed * * @exception NullPointerException if <code>base</code> or * <code>name</code> is <code>null</code> * @exception PropertyNotFoundException if the specified property name * does not exist */ public boolean isReadOnly(Object base, Object name) throws PropertyNotFoundException { if ((base == null) || (name == null)) { throw new NullPointerException(); } else if ((base instanceof DynaActionForm) && ("map".equals(name))) { return (true); } else if (base instanceof DynaBean) { if (getDynaProperty((DynaBean) base, name.toString()) == null) { throw new PropertyNotFoundException(name.toString()); } return (false); } else { return (resolver.isReadOnly(base, name.toString())); } } /** * <p>Return <code>true</code> if the value at the specified index of * the specified base object is known to be immutable; otherwise, * return <code>false</code>.</p> * * @param base The base object whose property is to analyzed * @param index Index of the value whose type is to be returned * * @exception IndexOutOfBoundsException if thrown by the underlying * accessed to the indexed property * @exception NullPointerException if <code>base</code> * is <code>null</code> * @exception PropertyNotFoundException if some other exception occurs */ public boolean isReadOnly(Object base, int index) throws PropertyNotFoundException { return (resolver.isReadOnly(base, index)); } /** * <p>Return the <code>java.lang.Class</code> representing the type of * the specified property of the specified base object, if it can be * determined; otherwise return <code>null</code>.</p> * * @param base The base object whose property is to analyzed * @param name Name of the property to be analyzed * * @exception NullPointerException if <code>base</code> or * <code>name</code> is <code>null</code> * @exception PropertyNotFoundException if the specified property name * does not exist */ public Class getType(Object base, Object name) throws PropertyNotFoundException { if ((base == null) || (name == null)) { throw new NullPointerException(); } else if ((base instanceof DynaActionForm) && ("map".equals(name))) { return (Map.class); } else if (base instanceof DynaBean) { DynaProperty dynaProperty = getDynaProperty((DynaBean) base, name.toString()); if (dynaProperty != null) { return (dynaProperty.getType()); } else { throw new PropertyNotFoundException(name.toString()); } } else { return (resolver.getType(base, name)); } } /** * <p>Return the <code>java.lang.Class</code> representing the type of * value at the specified index of the specified base object, or * <code>null</code> if this value is <code>null</code>.</p> * * @param base The base object whose property is to analyzed * @param index Index of the value whose type is to be returned * * @exception IndexOutOfBoundsException if thrown by the underlying * accessed to the indexed property * @exception NullPointerException if <code>base</code> * is <code>null</code> * @exception PropertyNotFoundException if some other exception occurs */ public Class getType(Object base, int index) throws PropertyNotFoundException { return (resolver.getType(base, index)); } // -------------------------------------------------------- Private Methods /** * <p>Return the <code>DynaProperty</code> describing the specified * property of the specified <code>DynaBean</code>, or <code>null</code> * if there is no such property defined on the underlying * <code>DynaClass</code>.</p> * * @param bean <code>DynaBean</code> to be checked * @param name Name of the property to be checked */ private DynaProperty getDynaProperty(DynaBean bean, String name) throws PropertyNotFoundException { DynaProperty dynaProperty = null; try { dynaProperty = bean.getDynaClass().getDynaProperty(name); } catch (IllegalArgumentException e) { ; } return (dynaProperty); } }