    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    }