| package org.apache.commons.digester3; |
| |
| /* |
| * 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. |
| */ |
| |
| import static java.lang.System.arraycopy; |
| import static java.lang.String.format; |
| import static org.apache.commons.beanutils.ConstructorUtils.getAccessibleConstructor; |
| import static org.apache.commons.beanutils.ConvertUtils.convert; |
| |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.Method; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| |
| import net.sf.cglib.proxy.Callback; |
| import net.sf.cglib.proxy.Enhancer; |
| import net.sf.cglib.proxy.Factory; |
| import net.sf.cglib.proxy.MethodInterceptor; |
| import net.sf.cglib.proxy.MethodProxy; |
| |
| import org.xml.sax.Attributes; |
| import org.xml.sax.SAXException; |
| |
| /** |
| * 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 |
| { |
| private static class DeferredConstructionCallback implements MethodInterceptor |
| { |
| Constructor<?> constructor; |
| Object[] constructorArgs; |
| ArrayList<RecordedInvocation> invocations = new ArrayList<RecordedInvocation>(); |
| Object delegate; |
| |
| DeferredConstructionCallback( Constructor<?> constructor, Object[] constructorArgs ) |
| { |
| this.constructor = constructor; |
| this.constructorArgs = constructorArgs; |
| } |
| |
| public Object intercept( Object obj, Method method, Object[] args, MethodProxy proxy ) |
| throws Throwable |
| { |
| boolean hasDelegate = delegate != null; |
| if ( !hasDelegate ) |
| { |
| invocations.add( new RecordedInvocation( method, args ) ); |
| } |
| if ( hasDelegate ) |
| { |
| return proxy.invoke( delegate, args ); |
| } |
| return proxy.invokeSuper( obj, args ); |
| } |
| |
| void establishDelegate() |
| throws Exception |
| { |
| convertTo( constructor.getParameterTypes(), constructorArgs ); |
| delegate = constructor.newInstance( constructorArgs ); |
| for ( RecordedInvocation invocation : invocations ) |
| { |
| invocation.getInvokedMethod().invoke( delegate, invocation.getArguments() ); |
| } |
| constructor = null; |
| constructorArgs = null; |
| invocations = null; |
| } |
| } |
| |
| private static class ProxyManager |
| { |
| private final Class<?> clazz; |
| private final Constructor<?> constructor; |
| private final Object[] templateConstructorArguments; |
| private final Digester digester; |
| private final boolean hasDefaultConstructor; |
| private Factory factory; |
| |
| ProxyManager( Class<?> clazz, Constructor<?> constructor, Object[] constructorArguments, Digester digester ) |
| { |
| this.clazz = clazz; |
| hasDefaultConstructor = getAccessibleConstructor( clazz, new Class[0] ) != null; |
| this.constructor = constructor; |
| Class<?>[] argTypes = constructor.getParameterTypes(); |
| templateConstructorArguments = new Object[argTypes.length]; |
| if ( constructorArguments == null ) |
| { |
| for ( int i = 0; i < templateConstructorArguments.length; i++ ) |
| { |
| if ( argTypes[i].equals( boolean.class ) ) |
| { |
| templateConstructorArguments[i] = Boolean.FALSE; |
| continue; |
| } |
| if ( argTypes[i].isPrimitive() ) |
| { |
| templateConstructorArguments[i] = convert( "0", argTypes[i] ); |
| continue; |
| } |
| templateConstructorArguments[i] = null; |
| } |
| } |
| else |
| { |
| if ( constructorArguments.length != argTypes.length ) |
| { |
| throw new IllegalArgumentException( |
| format( "wrong number of constructor arguments specified: %s instead of %s", |
| constructorArguments.length, argTypes.length ) ); |
| } |
| arraycopy( constructorArguments, 0, templateConstructorArguments, 0, constructorArguments.length ); |
| } |
| convertTo( argTypes, templateConstructorArguments ); |
| this.digester = digester; |
| } |
| |
| Object createProxy() |
| { |
| Object[] constructorArguments = new Object[templateConstructorArguments.length]; |
| arraycopy( templateConstructorArguments, 0, constructorArguments, 0, constructorArguments.length ); |
| digester.pushParams( constructorArguments ); |
| |
| DeferredConstructionCallback callback = |
| new DeferredConstructionCallback( constructor, constructorArguments ); |
| |
| Object result; |
| |
| if ( factory == null ) |
| { |
| Enhancer enhancer = new Enhancer(); |
| enhancer.setSuperclass( clazz ); |
| enhancer.setCallback( callback ); |
| enhancer.setClassLoader( digester.getClassLoader() ); |
| enhancer.setInterceptDuringConstruction( false ); |
| if ( hasDefaultConstructor ) |
| { |
| result = enhancer.create(); |
| } |
| else |
| { |
| result = enhancer.create( constructor.getParameterTypes(), constructorArguments ); |
| } |
| factory = (Factory) result; |
| return result; |
| } |
| |
| if ( hasDefaultConstructor ) |
| { |
| result = factory.newInstance( callback ); |
| } |
| else |
| { |
| result = factory.newInstance( constructor.getParameterTypes(), |
| constructorArguments, new Callback[] { callback } ); |
| } |
| return result; |
| } |
| |
| void finalize( Object proxy ) |
| throws Exception |
| { |
| digester.popParams(); |
| ( (DeferredConstructionCallback) ( (Factory) proxy ).getCallback( 0 ) ).establishDelegate(); |
| } |
| } |
| |
| // ----------------------------------------------------------- Constructors |
| |
| /** |
| * 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 ); |
| this.clazz = clazz; |
| } |
| |
| /** |
| * 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 ); |
| this.clazz = clazz; |
| } |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| /** |
| * The attribute containing an override class name if it is present. |
| */ |
| protected String attributeName = null; |
| |
| /** |
| * The Java class of the object to be created. |
| */ |
| protected Class<?> clazz = null; |
| |
| /** |
| * The Java class name of the object to be created. |
| */ |
| protected String className = null; |
| |
| /** |
| * The constructor argument types. |
| * |
| * @since 3.2 |
| */ |
| private Class<?>[] constructorArgumentTypes; |
| |
| /** |
| * The explictly specified default constructor arguments which may be overridden by CallParamRules. |
| * |
| * @since 3.2 |
| */ |
| private Object[] defaultConstructorArguments; |
| |
| /** |
| * Helper object for managing proxies. |
| * |
| * @since 3.2 |
| */ |
| private ProxyManager proxyManager; |
| |
| // --------------------------------------------------------- Public Methods |
| |
| /** |
| * Allows users to specify constructor argument types. |
| * |
| * @param constructorArgumentTypes the constructor argument types |
| * @since 3.2 |
| */ |
| public void setConstructorArgumentTypes( Class<?>... constructorArgumentTypes ) |
| { |
| if ( constructorArgumentTypes == null ) |
| { |
| throw new IllegalArgumentException( "Parameter 'constructorArgumentTypes' must not be null" ); |
| } |
| |
| this.constructorArgumentTypes = constructorArgumentTypes; |
| } |
| |
| /** |
| * Allows users to specify default constructor arguments. If a default/no-arg constructor is not available |
| * for the target class, these arguments will be used to create the proxy object. For any argument |
| * not supplied by a {@link CallParamRule}, the corresponding item from this array will be used |
| * to construct the final object as well. |
| * |
| * @param constructorArguments the default constructor arguments. |
| * @since 3.2 |
| */ |
| public void setDefaultConstructorArguments( Object... constructorArguments ) |
| { |
| if ( constructorArguments == null ) |
| { |
| throw new IllegalArgumentException( "Parameter 'constructorArguments' must not be null" ); |
| } |
| |
| this.defaultConstructorArguments = constructorArguments; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void begin( String namespace, String name, Attributes attributes ) |
| throws Exception |
| { |
| Class<?> clazz = this.clazz; |
| |
| if ( clazz == null ) |
| { |
| // Identify the name of the class to instantiate |
| String realClassName = className; |
| if ( attributeName != null ) |
| { |
| String value = attributes.getValue( attributeName ); |
| if ( value != null ) |
| { |
| realClassName = value; |
| } |
| } |
| if ( getDigester().getLogger().isDebugEnabled() ) |
| { |
| getDigester().getLogger().debug( format( "[ObjectCreateRule]{%s} New '%s'", |
| getDigester().getMatch(), |
| realClassName ) ); |
| } |
| |
| // Instantiate the new object and push it on the context stack |
| clazz = getDigester().getClassLoader().loadClass( realClassName ); |
| } |
| Object instance; |
| if ( constructorArgumentTypes == null || constructorArgumentTypes.length == 0 ) |
| { |
| if ( getDigester().getLogger().isDebugEnabled() ) |
| { |
| getDigester() |
| .getLogger() |
| .debug( format( "[ObjectCreateRule]{%s} New '%s' using default empty constructor", |
| getDigester().getMatch(), |
| clazz.getName() ) ); |
| } |
| |
| instance = clazz.newInstance(); |
| } |
| else |
| { |
| if ( proxyManager == null ) |
| { |
| Constructor<?> constructor = getAccessibleConstructor( clazz, constructorArgumentTypes ); |
| |
| if ( constructor == null ) |
| { |
| throw new SAXException( |
| format( "[ObjectCreateRule]{%s} Class '%s' does not have a construcor with types %s", |
| getDigester().getMatch(), |
| clazz.getName(), |
| Arrays.toString( constructorArgumentTypes ) ) ); |
| } |
| proxyManager = new ProxyManager( clazz, constructor, defaultConstructorArguments, getDigester() ); |
| } |
| instance = proxyManager.createProxy(); |
| } |
| getDigester().push( instance ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void end( String namespace, String name ) |
| throws Exception |
| { |
| Object top = getDigester().pop(); |
| |
| if ( proxyManager != null ) |
| { |
| proxyManager.finalize( top ); |
| } |
| |
| if ( getDigester().getLogger().isDebugEnabled() ) |
| { |
| getDigester().getLogger().debug( format( "[ObjectCreateRule]{%s} Pop '%s'", |
| getDigester().getMatch(), |
| top.getClass().getName() ) ); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() |
| { |
| return format( "ObjectCreateRule[className=%s, attributeName=%s]", className, attributeName ); |
| } |
| |
| private static void convertTo( Class<?>[] types, Object[] array ) |
| { |
| if ( array.length != types.length ) |
| { |
| throw new IllegalArgumentException(); |
| } |
| // this piece of code is adapted from CallMethodRule |
| for ( int i = 0; i < array.length; i++ ) |
| { |
| // convert nulls and convert stringy parameters for non-stringy param types |
| if ( array[i] == null |
| || ( array[i] instanceof String && !String.class.isAssignableFrom( types[i] ) ) ) |
| { |
| array[i] = convert( (String) array[i], types[i] ); |
| } |
| } |
| } |
| |
| } |