| /* $Id$ |
| * |
| * 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.tomcat.util.digester; |
| |
| import org.xml.sax.Attributes; |
| |
| |
| /** |
| * <p>Rule implementation that uses an {@link ObjectCreationFactory} to create |
| * a new object which it pushes onto the object stack. When the element is |
| * complete, the object will be popped.</p> |
| * |
| * <p>This rule is intended in situations where the element's attributes are |
| * needed before the object can be created. A common senario is for the |
| * ObjectCreationFactory implementation to use the attributes as parameters |
| * in a call to either a factory method or to a non-empty constructor. |
| */ |
| |
| public class FactoryCreateRule extends Rule { |
| |
| // ----------------------------------------------------------- Fields |
| |
| /** Should exceptions thrown by the factory be ignored? */ |
| private boolean ignoreCreateExceptions; |
| /** Stock to manage */ |
| private ArrayStack exceptionIgnoredStack; |
| |
| // ----------------------------------------------------------- Constructors |
| |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class name to create an {@link ObjectCreationFactory} which will |
| * then be used to create an object and push it on the stack. |
| * |
| * @param digester The associated Digester |
| * @param className Java class name of the object creation factory class |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #FactoryCreateRule(String className)} instead. |
| */ |
| public FactoryCreateRule(Digester digester, String className) { |
| |
| this(className); |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class to create an {@link ObjectCreationFactory} which will |
| * then be used to create an object and push it on the stack. |
| * |
| * @param digester The associated Digester |
| * @param clazz Java class name of the object creation factory class |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #FactoryCreateRule(Class clazz)} instead. |
| */ |
| public FactoryCreateRule(Digester digester, Class clazz) { |
| |
| this(clazz); |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class name (possibly overridden by the specified attribute if present) |
| * to create an {@link ObjectCreationFactory}, which will then be used |
| * to instantiate an object instance and push it onto the stack. |
| * |
| * @param digester The associated Digester |
| * @param className Default Java class name of the factory class |
| * @param attributeName Attribute name which, if present, contains an |
| * override of the class name of the object creation factory to create. |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #FactoryCreateRule(String className, String attributeName)} instead. |
| */ |
| public FactoryCreateRule(Digester digester, |
| String className, String attributeName) { |
| |
| this(className, attributeName); |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class (possibly overridden by the specified attribute if present) |
| * to create an {@link ObjectCreationFactory}, which will then be used |
| * to instantiate an object instance and push it onto the stack. |
| * |
| * @param digester The associated Digester |
| * @param clazz Default Java class name of the factory class |
| * @param attributeName Attribute name which, if present, contains an |
| * override of the class name of the object creation factory to create. |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #FactoryCreateRule(Class clazz, String attributeName)} instead. |
| */ |
| public FactoryCreateRule(Digester digester, |
| Class clazz, String attributeName) { |
| |
| this(clazz, attributeName); |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule using the given, already instantiated, |
| * {@link ObjectCreationFactory}. |
| * |
| * @param digester The associated Digester |
| * @param creationFactory called on to create the object. |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #FactoryCreateRule(ObjectCreationFactory creationFactory)} instead. |
| */ |
| public FactoryCreateRule(Digester digester, |
| ObjectCreationFactory creationFactory) { |
| |
| this(creationFactory); |
| |
| } |
| |
| /** |
| * <p>Construct a factory create rule that will use the specified |
| * class name to create an {@link ObjectCreationFactory} which will |
| * then be used to create an object and push it on the stack.</p> |
| * |
| * <p>Exceptions thrown during the object creation process will be propagated.</p> |
| * |
| * @param className Java class name of the object creation factory class |
| */ |
| public FactoryCreateRule(String className) { |
| |
| this(className, false); |
| |
| } |
| |
| |
| /** |
| * <p>Construct a factory create rule that will use the specified |
| * class to create an {@link ObjectCreationFactory} which will |
| * then be used to create an object and push it on the stack.</p> |
| * |
| * <p>Exceptions thrown during the object creation process will be propagated.</p> |
| * |
| * @param clazz Java class name of the object creation factory class |
| */ |
| public FactoryCreateRule(Class clazz) { |
| |
| this(clazz, false); |
| |
| } |
| |
| |
| /** |
| * <p>Construct a factory create rule that will use the specified |
| * class name (possibly overridden by the specified attribute if present) |
| * to create an {@link ObjectCreationFactory}, which will then be used |
| * to instantiate an object instance and push it onto the stack.</p> |
| * |
| * <p>Exceptions thrown during the object creation process will be propagated.</p> |
| * |
| * @param className Default Java class name of the factory class |
| * @param attributeName Attribute name which, if present, contains an |
| * override of the class name of the object creation factory to create. |
| */ |
| public FactoryCreateRule(String className, String attributeName) { |
| |
| this(className, attributeName, false); |
| |
| } |
| |
| |
| /** |
| * <p>Construct a factory create rule that will use the specified |
| * class (possibly overridden by the specified attribute if present) |
| * to create an {@link ObjectCreationFactory}, which will then be used |
| * to instantiate an object instance and push it onto the stack.</p> |
| * |
| * <p>Exceptions thrown during the object creation process will be propagated.</p> |
| * |
| * @param clazz Default Java class name of the factory class |
| * @param attributeName Attribute name which, if present, contains an |
| * override of the class name of the object creation factory to create. |
| */ |
| public FactoryCreateRule(Class clazz, String attributeName) { |
| |
| this(clazz, attributeName, false); |
| |
| } |
| |
| |
| /** |
| * <p>Construct a factory create rule using the given, already instantiated, |
| * {@link ObjectCreationFactory}.</p> |
| * |
| * <p>Exceptions thrown during the object creation process will be propagated.</p> |
| * |
| * @param creationFactory called on to create the object. |
| */ |
| public FactoryCreateRule(ObjectCreationFactory creationFactory) { |
| |
| this(creationFactory, false); |
| |
| } |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class name to create an {@link ObjectCreationFactory} which will |
| * then be used to create an object and push it on the stack. |
| * |
| * @param className Java class name of the object creation factory class |
| * @param ignoreCreateExceptions if true, exceptions thrown by the object |
| * creation factory |
| * will be ignored. |
| */ |
| public FactoryCreateRule(String className, boolean ignoreCreateExceptions) { |
| |
| this(className, null, ignoreCreateExceptions); |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class to create an {@link ObjectCreationFactory} which will |
| * then be used to create an object and push it on the stack. |
| * |
| * @param clazz Java class name of the object creation factory class |
| * @param ignoreCreateExceptions if true, exceptions thrown by the |
| * object creation factory |
| * will be ignored. |
| */ |
| public FactoryCreateRule(Class clazz, boolean ignoreCreateExceptions) { |
| |
| this(clazz, null, ignoreCreateExceptions); |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class name (possibly overridden by the specified attribute if present) |
| * to create an {@link ObjectCreationFactory}, which will then be used |
| * to instantiate an object instance and push it onto the stack. |
| * |
| * @param className Default Java class name of the factory class |
| * @param attributeName Attribute name which, if present, contains an |
| * override of the class name of the object creation factory to create. |
| * @param ignoreCreateExceptions if true, exceptions thrown by the object |
| * creation factory will be ignored. |
| */ |
| public FactoryCreateRule( |
| String className, |
| String attributeName, |
| boolean ignoreCreateExceptions) { |
| |
| this.className = className; |
| this.attributeName = attributeName; |
| this.ignoreCreateExceptions = ignoreCreateExceptions; |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule that will use the specified |
| * class (possibly overridden by the specified attribute if present) |
| * to create an {@link ObjectCreationFactory}, which will then be used |
| * to instantiate an object instance and push it onto the stack. |
| * |
| * @param clazz Default Java class name of the factory class |
| * @param attributeName Attribute name which, if present, contains an |
| * override of the class name of the object creation factory to create. |
| * @param ignoreCreateExceptions if true, exceptions thrown by the object |
| * creation factory will be ignored. |
| */ |
| public FactoryCreateRule( |
| Class clazz, |
| String attributeName, |
| boolean ignoreCreateExceptions) { |
| |
| this(clazz.getName(), attributeName, ignoreCreateExceptions); |
| |
| } |
| |
| |
| /** |
| * Construct a factory create rule using the given, already instantiated, |
| * {@link ObjectCreationFactory}. |
| * |
| * @param creationFactory called on to create the object. |
| * @param ignoreCreateExceptions if true, exceptions thrown by the object |
| * creation factory will be ignored. |
| */ |
| public FactoryCreateRule( |
| ObjectCreationFactory creationFactory, |
| boolean ignoreCreateExceptions) { |
| |
| this.creationFactory = creationFactory; |
| this.ignoreCreateExceptions = ignoreCreateExceptions; |
| } |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| |
| /** |
| * The attribute containing an override class name if it is present. |
| */ |
| protected String attributeName = null; |
| |
| |
| /** |
| * The Java class name of the ObjectCreationFactory to be created. |
| * This class must have a no-arguments constructor. |
| */ |
| protected String className = null; |
| |
| |
| /** |
| * The object creation factory we will use to instantiate objects |
| * as required based on the attributes specified in the matched XML |
| * element. |
| */ |
| protected ObjectCreationFactory creationFactory = null; |
| |
| |
| // --------------------------------------------------------- Public Methods |
| |
| |
| /** |
| * Process the beginning of this element. |
| * |
| * @param attributes The attribute list of this element |
| */ |
| public void begin(String namespace, String name, Attributes attributes) throws Exception { |
| |
| if (ignoreCreateExceptions) { |
| |
| if (exceptionIgnoredStack == null) { |
| exceptionIgnoredStack = new ArrayStack(); |
| } |
| |
| try { |
| Object instance = getFactory(attributes).createObject(attributes); |
| |
| if (digester.log.isDebugEnabled()) { |
| digester.log.debug("[FactoryCreateRule]{" + digester.match + |
| "} New " + instance.getClass().getName()); |
| } |
| digester.push(instance); |
| exceptionIgnoredStack.push(Boolean.FALSE); |
| |
| } catch (Exception e) { |
| // log message and error |
| if (digester.log.isInfoEnabled()) { |
| digester.log.info("[FactoryCreateRule] Create exception ignored: " + |
| ((e.getMessage() == null) ? e.getClass().getName() : e.getMessage())); |
| if (digester.log.isDebugEnabled()) { |
| digester.log.debug("[FactoryCreateRule] Ignored exception:", e); |
| } |
| } |
| exceptionIgnoredStack.push(Boolean.TRUE); |
| } |
| |
| } else { |
| Object instance = getFactory(attributes).createObject(attributes); |
| |
| if (digester.log.isDebugEnabled()) { |
| digester.log.debug("[FactoryCreateRule]{" + digester.match + |
| "} New " + instance.getClass().getName()); |
| } |
| digester.push(instance); |
| } |
| } |
| |
| |
| /** |
| * Process the end of this element. |
| */ |
| public void end(String namespace, String name) throws Exception { |
| |
| // check if object was created |
| // this only happens if an exception was thrown and we're ignoring them |
| if ( |
| ignoreCreateExceptions && |
| exceptionIgnoredStack != null && |
| !(exceptionIgnoredStack.empty())) { |
| |
| if (((Boolean) exceptionIgnoredStack.pop()).booleanValue()) { |
| // creation exception was ignored |
| // nothing was put onto the stack |
| if (digester.log.isTraceEnabled()) { |
| digester.log.trace("[FactoryCreateRule] No creation so no push so no pop"); |
| } |
| return; |
| } |
| } |
| |
| Object top = digester.pop(); |
| if (digester.log.isDebugEnabled()) { |
| digester.log.debug("[FactoryCreateRule]{" + digester.match + |
| "} Pop " + top.getClass().getName()); |
| } |
| |
| } |
| |
| |
| /** |
| * Clean up after parsing is complete. |
| */ |
| public void finish() throws Exception { |
| |
| if (attributeName != null) { |
| creationFactory = null; |
| } |
| |
| } |
| |
| |
| /** |
| * Render a printable version of this Rule. |
| */ |
| public String toString() { |
| |
| StringBuffer sb = new StringBuffer("FactoryCreateRule["); |
| sb.append("className="); |
| sb.append(className); |
| sb.append(", attributeName="); |
| sb.append(attributeName); |
| if (creationFactory != null) { |
| sb.append(", creationFactory="); |
| sb.append(creationFactory); |
| } |
| sb.append("]"); |
| return (sb.toString()); |
| |
| } |
| |
| |
| // ------------------------------------------------------ Protected Methods |
| |
| |
| /** |
| * Return an instance of our associated object creation factory, |
| * creating one if necessary. |
| * |
| * @param attributes Attributes passed to our factory creation element |
| * |
| * @exception Exception if any error occurs |
| */ |
| protected ObjectCreationFactory getFactory(Attributes attributes) |
| throws Exception { |
| |
| if (creationFactory == null) { |
| String realClassName = className; |
| if (attributeName != null) { |
| String value = attributes.getValue(attributeName); |
| if (value != null) { |
| realClassName = value; |
| } |
| } |
| if (digester.log.isDebugEnabled()) { |
| digester.log.debug("[FactoryCreateRule]{" + digester.match + |
| "} New factory " + realClassName); |
| } |
| Class clazz = digester.getClassLoader().loadClass(realClassName); |
| creationFactory = (ObjectCreationFactory) |
| clazz.newInstance(); |
| creationFactory.setDigester(digester); |
| } |
| return (creationFactory); |
| |
| } |
| } |