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 }