    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    package org.apache.commons.jexl2;
    018
    019    import java.util.HashMap;
    020    import java.util.Map;
    021
    022    /**
    023     * Wraps a map in a context.
    024     * <p>Each entry in the map is considered a variable name, value pair.</p>
    025     */
    026    public class MapContext implements JexlContext {
    027        /**
    028         * The wrapped variable map.
    029         */
    030        protected final Map<String, Object> map;
    031
    032        /**
    033         * Creates a MapContext on an automatically allocated underlying HashMap.
    034         */
    035        public MapContext() {
    036            this(null);
    037        }
    038
    039        /**
    040         * Creates a MapContext wrapping an existing user provided map.
    041         * @param vars the variable map
    042         */
    043        public MapContext(Map<String, Object> vars) {
    044            super();
    045            map = vars == null ? new HashMap<String, Object>() : vars;
    046        }
    047
    048        /** {@inheritDoc} */
    049        public boolean has(String name) {
    050            return map.containsKey(name);
    051        }
    052
    053        /** {@inheritDoc} */
    054        public Object get(String name) {
    055            return map.get(name);
    056        }
    057
    058        /** {@inheritDoc} */
    059        public void set(String name, Object value) {
    060            map.put(name, value);
    061        }
    062    }