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; 019 020import java.util.HashMap; 021import java.util.Map; 022 023/** 024 * Wraps a map in a context. 025 * <p>Each entry in the map is considered a variable name, value pair.</p> 026 */ 027public class MapContext implements JexlContext { 028 029 /** 030 * The wrapped variable map. 031 */ 032 private final Map<String, Object> map; 033 034 /** 035 * Creates a MapContext on an automatically allocated underlying HashMap. 036 */ 037 public MapContext() { 038 this(null); 039 } 040 041 /** 042 * Creates a MapContext wrapping an existing user provided map. 043 * 044 * @param vars the variable map 045 */ 046 public MapContext(final Map<String, Object> vars) { 047 map = vars == null ? new HashMap<>() : vars; 048 } 049 050 @Override 051 public boolean has(final String name) { 052 return map.containsKey(name); 053 } 054 055 @Override 056 public Object get(final String name) { 057 return map.get(name); 058 } 059 060 @Override 061 public void set(final String name, final Object value) { 062 map.put(name, value); 063 } 064 065 /** 066 * Clears all variables. 067 */ 068 public void clear() { 069 map.clear(); 070 } 071}