Java tutorial
/* $Id: ObjectCreateRule.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.xml.sax.Attributes; /** * Rule implementation that creates a new object and pushes it * onto the object stack. When the element is complete, the * object will be popped */ public class ObjectCreateRule extends Rule { // ----------------------------------------------------------- Constructors /** * Construct an object create rule with the specified class name. * * @param digester The associated Digester * @param className Java class name of the object to be created * * @deprecated The digester instance is now set in the {@link Digester#addRule} method. * Use {@link #ObjectCreateRule(String className)} instead. */ @Deprecated public ObjectCreateRule(Digester digester, String className) { this(className); } /** * Construct an object create rule with the specified class. * * @param digester The associated Digester * @param clazz Java class name of the object to be created * * @deprecated The digester instance is now set in the {@link Digester#addRule} method. * Use {@link #ObjectCreateRule(Class clazz)} instead. */ @Deprecated public ObjectCreateRule(Digester digester, Class<?> clazz) { this(clazz); } /** * Construct an object create rule with the specified class name and an * optional attribute name containing an override. * * @param digester The associated Digester * @param className Java class name of the object to be created * @param attributeName Attribute name which, if present, contains an * override of the class name to create * * @deprecated The digester instance is now set in the {@link Digester#addRule} method. * Use {@link #ObjectCreateRule(String className, String attributeName)} instead. */ @Deprecated public ObjectCreateRule(Digester digester, String className, String attributeName) { this(className, attributeName); } /** * Construct an object create rule with the specified class and an * optional attribute name containing an override. * * @param digester The associated Digester * @param attributeName Attribute name which, if present, contains an * @param clazz Java class name of the object to be created * override of the class name to create * * @deprecated The digester instance is now set in the {@link Digester#addRule} method. * Use {@link #ObjectCreateRule(String attributeName, Class clazz)} instead. */ @Deprecated public ObjectCreateRule(Digester digester, String attributeName, Class<?> clazz) { this(attributeName, clazz); } /** * Construct an object create rule with the specified class name. * * @param className Java class name of the object to be created */ public ObjectCreateRule(String className) { this(className, (String) null); } /** * Construct an object create rule with the specified class. * * @param clazz Java class name of the object to be created */ public ObjectCreateRule(Class<?> clazz) { this(clazz.getName(), (String) null); } /** * Construct an object create rule with the specified class name and an * optional attribute name containing an override. * * @param className Java class name of the object to be created * @param attributeName Attribute name which, if present, contains an * override of the class name to create */ public ObjectCreateRule(String className, String attributeName) { this.className = className; this.attributeName = attributeName; } /** * Construct an object create rule with the specified class and an * optional attribute name containing an override. * * @param attributeName Attribute name which, if present, contains an * @param clazz Java class name of the object to be created * override of the class name to create */ public ObjectCreateRule(String attributeName, Class<?> clazz) { this(clazz.getName(), attributeName); } // ----------------------------------------------------- Instance Variables /** * The attribute containing an override class name if it is present. */ protected String attributeName = null; /** * The Java class name of the object to be created. */ protected String className = null; // --------------------------------------------------------- Public Methods /** * Process the beginning of this element. * * @param attributes The attribute list of this element */ @Override public void begin(Attributes attributes) throws Exception { // Identify the name of the class to instantiate String realClassName = className; if (attributeName != null) { String value = attributes.getValue(attributeName); if (value != null) { realClassName = value; } } // Instantiate the new object and push it on the context stack Class<?> clazz = digester.getClassLoader().loadClass(realClassName); Object instance = clazz.newInstance(); digester.push(instance); } /** * Process the end of this element. */ @Override public void end() throws Exception { Object top = digester.pop(); } /** * Render a printable version of this Rule. */ @Override public String toString() { StringBuffer sb = new StringBuffer("ObjectCreateRule["); sb.append("className="); sb.append(className); sb.append(", attributeName="); sb.append(attributeName); sb.append("]"); return (sb.toString()); } }