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    /**
020     * A readonly context wrapper.
021     * @since 2.1
022     */
023    public final class ReadonlyContext implements JexlContext {
024        /** The wrapped context. */
025        private final JexlContext wrapped;
026    
027        /**
028         * Creates a new readonly context.
029         * @param context the wrapped context
030         */
031        public ReadonlyContext(JexlContext context) {
032            wrapped = context;
033        }
034    
035        /** {@inheritDoc} */
036        public Object get(String name) {
037            return wrapped.get(name);
038        }
039    
040        /** 
041         * Will throw an UnsupportedOperationException when called; the JexlEngine deals with it appropriately.
042         * @param name the unused variable name
043         * @param value the unused variable value
044         */
045        public void set(String name, Object value) {
046            throw new UnsupportedOperationException("Not supported.");
047        }
048    
049        /** {@inheritDoc} */
050        public boolean has(String name) {
051            return wrapped.has(name);
052        }
053    }