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.jexl;
019
020import org.apache.commons.jexl.context.HashMapContext;
021
022/**
023 *  Helper to create a context.  In the current implementation of JEXL, there
024 *  is one implementation of JexlContext - {@link HashMapContext}, and there
025 *  is no reason not to directly instantiate {@link HashMapContext} in your
026 *  own application.
027 *
028 *  @since 1.0
029 *  
030 *  @version $Id$
031 */
032public class JexlHelper {
033    /** singleton instance. */
034    protected static JexlHelper helper = new JexlHelper();
035
036    /** @return the single instance. */
037    protected static JexlHelper getInstance() {
038        return helper;
039    }
040
041    /**
042     * Returns a new {@link JexlContext}.
043     * @return a new JexlContext
044     */
045    public static JexlContext createContext() {
046        return getInstance().newContext();
047    }
048
049    /**
050     * Creates and returns a new {@link JexlContext}.  
051     * The current implementation creates a new instance of 
052     * {@link HashMapContext}.
053     * @return a new JexlContext
054     */
055    protected JexlContext newContext() {
056        return new HashMapContext();
057    }
058}