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
018package org.apache.commons.jexl2.internal;
019import java.util.Map;
020import java.lang.reflect.InvocationTargetException;
021/**
022 * Specialized executor to set a property in a Map.
023 * @since 2.0
024 */
025public 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}