001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.jexl2.internal;
019 import java.util.Map;
020 import java.lang.reflect.InvocationTargetException;
021 /**
022 * Specialized executor to set a property in a Map.
023 * @since 2.0
024 */
025 public final class MapSetExecutor extends AbstractExecutor.Set {
026 /** The java.util.map.put method used as an active marker in MapSet. */
027 private static final java.lang.reflect.Method MAP_SET = initMarker(Map.class, "put", Object.class, Object.class);
028 /** The property. */
029 private final Object property;
030
031 /**
032 * Creates an instance checking for the Map interface.
033 *@param is the introspector
034 *@param clazz the class that might implement the map interface
035 *@param key the key to use as argument in map.put(key,value)
036 *@param value the value to use as argument in map.put(key,value)
037 */
038 public MapSetExecutor(Introspector is, Class<?> clazz, Object key, Object value) {
039 super(clazz, discover(clazz));
040 property = key;
041 }
042
043 /** {@inheritDoc} */
044 @Override
045 public Object getTargetProperty() {
046 return property;
047 }
048
049 /** {@inheritDoc} */
050 @Override
051 public Object execute(final Object obj, Object value)
052 throws IllegalAccessException, InvocationTargetException {
053 @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
054 final Map<Object,Object> map = ((Map<Object, Object>) obj);
055 map.put(property, value);
056 return value;
057 }
058
059 /** {@inheritDoc} */
060 @Override
061 public Object tryExecute(final Object obj, Object key, Object value) {
062 if (obj != null && method != null
063 && objectClass.equals(obj.getClass())
064 && (key == null || property.getClass().equals(key.getClass()))) {
065 @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
066 final Map<Object,Object> map = ((Map<Object, Object>) obj);
067 map.put(key, value);
068 return value;
069 }
070 return TRY_FAILED;
071 }
072
073 /**
074 * Finds the method to perform 'set' on a map.
075 * @param clazz the class to introspect
076 * @return a marker method, map.get
077 */
078 static java.lang.reflect.Method discover(Class<?> clazz) {
079 return (Map.class.isAssignableFrom(clazz))? MAP_SET : null;
080 }
081 }