| package org.apache.velocity.runtime.parser.node; |
| |
| /* |
| * 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 org.apache.commons.lang3.StringUtils; |
| import org.apache.velocity.exception.VelocityException; |
| import org.apache.velocity.util.introspection.Introspector; |
| import org.slf4j.Logger; |
| |
| import java.lang.reflect.Field; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Modifier; |
| |
| /** |
| * Executor for setting public fields in objects |
| * |
| * @author <a href="mailto:henning@apache.org">Henning P. Schmiedehausen</a> |
| * @author <a href="mailto:cdauth@cdauth.eu">Candid Dauth</a> |
| */ |
| public class SetPublicFieldExecutor |
| extends SetExecutor |
| { |
| private final Introspector introspector; |
| |
| /** |
| * Field to be accessed |
| */ |
| private Field field = null; |
| |
| /** |
| * @param log |
| * @param introspector |
| * @param clazz |
| * @param property |
| * @param arg |
| */ |
| public SetPublicFieldExecutor(final Logger log, final Introspector introspector, |
| final Class clazz, final String property, final Object arg) |
| { |
| this.log = log; |
| this.introspector = introspector; |
| |
| // Don't allow passing in the empty string or null because |
| // it will either fail with a StringIndexOutOfBounds error |
| // or the introspector will get confused. |
| if (StringUtils.isNotEmpty(property)) |
| { |
| discover(clazz, property, arg); |
| } |
| } |
| |
| public boolean isAlive() { |
| return getField() != null; |
| } |
| |
| /** |
| * @return The current field. |
| */ |
| public Field getField() |
| { |
| return field; |
| } |
| |
| /** |
| * @param field |
| */ |
| protected void setField(final Field field) |
| { |
| this.field = field; |
| } |
| |
| /** |
| * @return The current introspector. |
| */ |
| protected Introspector getIntrospector() |
| { |
| return this.introspector; |
| } |
| |
| /** |
| * @param clazz |
| * @param property |
| * @param arg |
| */ |
| protected void discover(final Class clazz, final String property, final Object arg) |
| { |
| try |
| { |
| Field field = introspector.getField(clazz, property); |
| if(!Modifier.isFinal(field.getModifiers())) |
| { |
| setField(field); |
| } |
| } |
| /** |
| * pass through application level runtime exceptions |
| */ |
| catch( RuntimeException e ) |
| { |
| throw e; |
| } |
| catch(Exception e) |
| { |
| String msg = "Exception while looking for public field '" + property; |
| log.error(msg, e); |
| throw new VelocityException(msg, e); |
| } |
| } |
| |
| /** |
| * Execute method against context. |
| * @param o |
| * @param value |
| * @return The value of the invocation. |
| * @throws IllegalAccessException |
| * @throws InvocationTargetException |
| */ |
| public Object execute(final Object o, final Object value) |
| throws IllegalAccessException, InvocationTargetException |
| { |
| if (isAlive()) |
| { |
| Object oldValue = getField().get(o); |
| getField().set(o, value); |
| return oldValue; |
| } |
| else |
| return null; |
| } |
| } |