/* $Id: SetTopRule.java 992060 2010-09-02 19:09:47Z simonetripodi $ * * 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.digester; import org.apache.commons.beanutils.MethodUtils; /** *

Rule implementation that calls a "set parent" method on the top (child) * object, passing the (top-1) (parent) object as an argument.

* *

This rule now supports more flexible method matching by default. * It is possible that this may break (some) code * written against release 1.1.1 or earlier. * See {@link #isExactMatch()} for more details.

*/ public class SetTopRule extends Rule { // ----------------------------------------------------------- Constructors /** * Construct a "set parent" rule with the specified method name. The * "set parent" method's argument type is assumed to be the class of the * parent object. * * @param digester The associated Digester * @param methodName Method name of the "set parent" method to call * * @deprecated The digester instance is now set in the {@link Digester#addRule} method. * Use {@link #SetTopRule(String methodName)} instead. */ @Deprecated public SetTopRule(Digester digester, String methodName) { this(methodName); } /** * Construct a "set parent" rule with the specified method name. * * @param digester The associated Digester * @param methodName Method name of the "set parent" method to call * @param paramType Java class of the "set parent" method's argument * (if you wish to use a primitive type, specify the corresonding * Java wrapper class instead, such as java.lang.Boolean * for a boolean parameter) * * @deprecated The digester instance is now set in the {@link Digester#addRule} method. * Use {@link #SetTopRule(String methodName, String paramType)} instead. */ @Deprecated public SetTopRule(Digester digester, String methodName, String paramType) { this(methodName, paramType); } /** * Construct a "set parent" rule with the specified method name. The * "set parent" method's argument type is assumed to be the class of the * parent object. * * @param methodName Method name of the "set parent" method to call */ public SetTopRule(String methodName) { this(methodName, null); } /** * Construct a "set parent" rule with the specified method name. * * @param methodName Method name of the "set parent" method to call * @param paramType Java class of the "set parent" method's argument * (if you wish to use a primitive type, specify the corresonding * Java wrapper class instead, such as java.lang.Boolean * for a boolean parameter) */ public SetTopRule(String methodName, String paramType) { this.methodName = methodName; this.paramType = paramType; } // ----------------------------------------------------- Instance Variables /** * The method name to call on the child object. */ protected String methodName = null; /** * The Java class name of the parameter type expected by the method. */ protected String paramType = null; /** * Should we use exact matching. Default is no. */ protected boolean useExactMatch = false; // --------------------------------------------------------- Public Methods /** *

Is exact matching being used.

* *

This rule uses org.apache.commons.beanutils.MethodUtils * to introspect the relevent objects so that the right method can be called. * Originally, MethodUtils.invokeExactMethod was used. * This matches methods very strictly * and so may not find a matching method when one exists. * This is still the behaviour when exact matching is enabled.

* *

When exact matching is disabled, MethodUtils.invokeMethod is used. * This method finds more methods but is less precise when there are several methods * with correct signatures. * So, if you want to choose an exact signature you might need to enable this property.

* *

The default setting is to disable exact matches.

* * @return true iff exact matching is enabled * @since Digester Release 1.1.1 */ public boolean isExactMatch() { return useExactMatch; } /** *

Set whether exact matching is enabled.

* *

See {@link #isExactMatch()}.

* * @param useExactMatch should this rule use exact method matching * @since Digester Release 1.1.1 */ public void setExactMatch(boolean useExactMatch) { this.useExactMatch = useExactMatch; } /** * Process the end of this element. */ @Override public void end() throws Exception { // Identify the objects to be used Object child = digester.peek(0); Object parent = digester.peek(1); if (digester.log.isDebugEnabled()) { if (child == null) { digester.log.debug("[SetTopRule]{" + digester.match + "} Call [NULL CHILD]." + methodName + "(" + parent + ")"); } else { digester.log.debug("[SetTopRule]{" + digester.match + "} Call " + child.getClass().getName() + "." + methodName + "(" + parent + ")"); } } // Call the specified method Class paramTypes[] = new Class[1]; if (paramType != null) { paramTypes[0] = digester.getClassLoader().loadClass(paramType); } else { paramTypes[0] = parent.getClass(); } if (useExactMatch) { MethodUtils.invokeExactMethod(child, methodName, new Object[]{ parent }, paramTypes); } else { MethodUtils.invokeMethod(child, methodName, new Object[]{ parent }, paramTypes); } } /** * Render a printable version of this Rule. */ @Override public String toString() { StringBuffer sb = new StringBuffer("SetTopRule["); sb.append("methodName="); sb.append(methodName); sb.append(", paramType="); sb.append(paramType); sb.append("]"); return (sb.toString()); } }