| package org.apache.velocity.tools.view; |
| |
| /* |
| * 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 javax.servlet.http.HttpServletRequest; |
| import javax.servlet.http.HttpSession; |
| import javax.servlet.ServletContext; |
| import java.lang.reflect.InvocationTargetException; |
| |
| import org.slf4j.Logger; |
| |
| import org.apache.velocity.util.introspection.AbstractChainableUberspector; |
| import org.apache.velocity.util.introspection.Info; |
| import org.apache.velocity.util.introspection.Introspector; |
| import org.apache.velocity.util.introspection.VelPropertyGet; |
| import org.apache.velocity.util.introspection.VelPropertySet; |
| import org.apache.velocity.runtime.parser.node.AbstractExecutor; |
| import org.apache.velocity.runtime.parser.node.SetExecutor; |
| |
| /** |
| * <p>This custom uberspector allows getAttribute() and setAttribute() as standard |
| * getters and setters for the "request","session" and "application" keys. |
| * <p>It allows VTL statements like: |
| * <pre> |
| * #set($session.foo = 'youpi') |
| * session parameter 'foo' has value: $session.foo |
| * </pre> |
| * </p> |
| * <p>This uberspector requires Velocity 1.6+ ; to use it, you must specify <code>org.apache.velocity.tools.view.WebappUberspector</code> |
| * as the last uberspector to the <code>runtime.introspector.uberspect</code> property in you <code>velocity.properties</code> file.</p> |
| * |
| * <p>For instance:</p> |
| * |
| * <p><code>runtime.introspector.uberspect = org.apache.velocity.util.introspection.UberspectImpl,org.apache.velocity.tools.view.WebappUberspector</code></p> |
| * |
| * @author <a href="mailto:cbrisson@apache.org">Claude Brisson</a> |
| * @version $Id: WebappUberspector.java $ */ |
| |
| public class WebappUberspector extends AbstractChainableUberspector |
| { |
| |
| /** |
| * Property getter |
| * @param obj |
| * @param identifier |
| * @param i |
| * @return A Velocity Getter Method. |
| * @throws Exception |
| */ |
| public VelPropertyGet getPropertyGet(Object obj, String identifier, Info i) |
| { |
| if (obj == null) |
| { |
| return null; |
| } |
| VelPropertyGet ret = super.getPropertyGet(obj,identifier,i); |
| |
| if(ret == null) |
| { |
| Class claz = obj.getClass(); |
| if(obj instanceof HttpServletRequest |
| || obj instanceof HttpSession |
| || obj instanceof ServletContext) |
| { |
| AbstractExecutor executor = new GetAttributeExecutor(log, introspector, claz, identifier); |
| ret = executor.isAlive() ? new VelGetterImpl(executor) : null; |
| } |
| } |
| return ret; |
| } |
| |
| /** |
| * init method |
| */ |
| @Override |
| public void init() |
| { |
| super.init(); |
| |
| // we need our own introspector since the inner one is hidden by the Uberspect interface |
| introspector = new Introspector(log); |
| } |
| |
| /** |
| * Property setter |
| * @param obj |
| * @param identifier |
| * @param arg |
| * @param i |
| * @return A Velocity Setter method. |
| * @throws Exception |
| */ |
| public VelPropertySet getPropertySet(Object obj, String identifier, |
| Object arg, Info i) |
| { |
| if (obj == null) |
| { |
| return null; |
| } |
| VelPropertySet ret = super.getPropertySet(obj,identifier,arg,i); |
| |
| if(ret == null) { |
| Class claz = obj.getClass(); |
| if(obj instanceof HttpServletRequest |
| || obj instanceof HttpSession |
| || obj instanceof ServletContext) |
| { |
| SetExecutor executor = new SetAttributeExecutor(log, introspector, claz, arg, identifier); |
| ret = executor.isAlive() ? new VelSetterImpl(executor) : null; |
| } |
| } |
| return ret; |
| } |
| |
| |
| /** |
| * Executor for getAttribute(name) method. |
| */ |
| public class GetAttributeExecutor extends AbstractExecutor |
| { |
| private final Introspector introspector; |
| |
| // This is still threadsafe because this object is only read except in the C'tor. |
| private Object [] params; |
| |
| /** |
| * @param log |
| * @param introspector |
| * @param clazz |
| * @param property |
| */ |
| public GetAttributeExecutor(final Logger log, final Introspector introspector, |
| final Class clazz, final String property) |
| { |
| this.log = log; |
| this.introspector = introspector; |
| this.params = new Object[] { property }; |
| |
| discover(clazz); |
| } |
| |
| protected void discover(final Class clazz) |
| { |
| try |
| { |
| setMethod(introspector.getMethod(clazz, "getAttribute", params)); |
| } |
| /** |
| * pass through application level runtime exceptions |
| */ |
| catch( RuntimeException e ) |
| { |
| throw e; |
| } |
| catch(Exception e) |
| { |
| log.error("While looking for getAttribute('{}') method:", params[0], e); |
| } |
| } |
| |
| /** |
| * @see org.apache.velocity.runtime.parser.node.AbstractExecutor#execute(java.lang.Object) |
| */ |
| public Object execute(final Object o) |
| throws IllegalAccessException, InvocationTargetException |
| { |
| return isAlive() ? getMethod().invoke(o, params) : null; |
| } |
| } |
| |
| /** |
| * Executor for setAttribute(name,value) method |
| */ |
| public class SetAttributeExecutor extends SetExecutor |
| { |
| private final Introspector introspector; |
| private final String property; |
| |
| /** |
| * @param log |
| * @param introspector |
| * @param clazz |
| * @param arg |
| * @param property |
| */ |
| public SetAttributeExecutor(final Logger log, final Introspector introspector, |
| final Class clazz, final Object arg, final String property) |
| { |
| this.log = log; |
| this.introspector = introspector; |
| this.property = property; |
| |
| discover(clazz, arg); |
| } |
| |
| /** |
| * @param clazz |
| * @param arg |
| */ |
| protected void discover(final Class clazz, final Object arg) |
| { |
| Object [] params = new Object[] { property, arg }; |
| |
| try |
| { |
| setMethod(introspector.getMethod(clazz, "setAttribute", params)); |
| } |
| /** |
| * pass through application level runtime exceptions |
| */ |
| catch( RuntimeException e ) |
| { |
| throw e; |
| } |
| catch(Exception e) |
| { |
| log.error("While looking for put('{}') method:", params[0], e); |
| } |
| } |
| |
| /** |
| * @see org.apache.velocity.runtime.parser.node.SetExecutor#execute(java.lang.Object, java.lang.Object) |
| */ |
| public Object execute(final Object o, final Object value) |
| throws IllegalAccessException, InvocationTargetException |
| { |
| Object [] params; |
| |
| if (isAlive()) |
| { |
| params = new Object [] { property, value }; |
| return getMethod().invoke(o, params); |
| } |
| |
| return null; |
| } |
| } |
| } |