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.jexl3.internal.introspection;
019import java.util.Map;
020
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    /** The property value class. */
031    private final Class<?> valueClass;
032
033    /**
034     * Attempts to discover a MapSetExecutor.
035     *
036     * @param is the introspector
037     * @param clazz the class to find the set method from
038     * @param identifier the key to use as an argument to the get method
039     * @param value the value to use as argument in map.put(key,value)
040     * @return the executor if found, null otherwise
041     */
042    public static MapSetExecutor discover(final Introspector is,
043                                          final Class<?> clazz,
044                                          final Object identifier,
045                                          final Object value) {
046        if (Map.class.isAssignableFrom(clazz)) {
047            return new MapSetExecutor(clazz, MAP_SET, identifier, value);
048        }
049        return null;
050    }
051
052    /**
053     * Creates an instance.
054     * @param clazz the class the set method applies to
055     * @param method the method called through this executor
056     * @param key the key to use as 1st argument to the set method
057     * @param value the value to use as 2nd argument to the set method
058     */
059    private MapSetExecutor(final Class<?> clazz, final java.lang.reflect.Method method, final Object key, final Object value) {
060        super(clazz, method);
061        property = key;
062        valueClass = classOf(value);
063    }
064
065    @Override
066    public Object getTargetProperty() {
067        return property;
068    }
069
070    @Override
071    public Object invoke(final Object obj, final Object value) {
072        @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
073        final Map<Object,Object> map = ((Map<Object, Object>) obj);
074        map.put(property, value);
075        return value;
076    }
077
078    @Override
079    public Object tryInvoke(final Object obj, final Object key, final Object value) {
080        if (obj != null
081            && method != null
082            && objectClass.equals(obj.getClass())
083            && ((property == null && key == null)
084                || (property != null && key != null && property.getClass().equals(key.getClass())))
085            && valueClass.equals(classOf(value))) {
086            @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
087            final Map<Object,Object> map = ((Map<Object, Object>) obj);
088            map.put(key, value);
089            return value;
090        }
091        return TRY_FAILED;
092    }
093}