/* | |
* 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.click.service; | |
import java.io.IOException; | |
import java.io.Serializable; | |
import java.util.HashMap; | |
import java.util.Map; | |
import java.util.concurrent.ConcurrentHashMap; | |
import javax.servlet.ServletContext; | |
import org.apache.click.util.ClassLoaderCache; | |
import org.apache.click.util.PropertyUtils; | |
import org.mvel2.MVEL; | |
/** | |
* Provides an MVEL based property services. | |
*/ | |
public class MVELPropertyService implements PropertyService { | |
// Expression cache with support for multiple classloader caching | |
private static final ClassLoaderCache<Map<String, Serializable>> | |
EXPRESSION_CL_CACHE = new ClassLoaderCache<Map<String, Serializable>>(); | |
// Public Methods -------------------------------------------------------- | |
/** | |
* @see PropertyService#onInit(ServletContext) | |
* | |
* @param servletContext the application servlet context | |
* @throws IOException if an IO error occurs initializing the service | |
*/ | |
public void onInit(ServletContext servletContext) throws IOException { | |
} | |
/** | |
* @see PropertyService#onDestroy() | |
*/ | |
public void onDestroy() { | |
} | |
/** | |
* @see PropertyService#getValue(Object, String) | |
* | |
* @param source the source object | |
* @param name the name of the property | |
* @return the property value for the given source object and property name | |
*/ | |
public Object getValue(Object source, String name) { | |
return PropertyUtils.getValue(source, name); | |
} | |
/** | |
* @see PropertyService#getValue(Object, String, Map) | |
* | |
* @param source the source object | |
* @param name the name of the property | |
* @param cache the cache of reflected property Method objects, do NOT modify | |
* this cache | |
* @return the property value for the given source object and property name | |
*/ | |
public Object getValue(Object source, String name, Map<?, ?> cache) { | |
return PropertyUtils.getValue(source, name, cache); | |
} | |
/** | |
* Set the named property value on the target object using the MVEL library. | |
* | |
* @see PropertyService#setValue(Object, String, Object) | |
* | |
* @param target the target object to set the property of | |
* @param name the name of the property to set | |
* @param value the property value to set | |
*/ | |
public void setValue(Object target, String name, Object value) { | |
String expression = target.getClass().getSimpleName() + "." + name + " = value"; | |
Serializable compiledExpression = getExpressionCache().get(expression); | |
if (compiledExpression == null) { | |
compiledExpression = MVEL.compileExpression(expression); | |
getExpressionCache().put(expression, compiledExpression); | |
} | |
Map<String, Object> vars = new HashMap<String, Object>(); | |
vars.put(target.getClass().getSimpleName(), target); | |
vars.put("value", value); | |
MVEL.executeExpression(compiledExpression, vars); | |
} | |
// Private Methods -------------------------------------------------------- | |
private static Map<String, Serializable> getExpressionCache() { | |
Map<String, Serializable> expressionCache = EXPRESSION_CL_CACHE.get(); | |
if (expressionCache == null) { | |
expressionCache = new ConcurrentHashMap<String, Serializable>(); | |
EXPRESSION_CL_CACHE.put(expressionCache); | |
} | |
return expressionCache; | |
} | |
} |