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 */ 017 018 package org.apache.commons.jexl2; 019 020 021 /** 022 * Represents a single JEXL expression. 023 * <p> 024 * This simple interface provides access to the underlying expression through 025 * {@link Expression#getExpression()}. 026 * </p> 027 * 028 * <p> 029 * An expression is different than a script - it is simply a reference of 030 * an expression. 031 * </p> 032 * 033 * @since 1.0 034 * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a> 035 * @version $Id: Expression.java 884175 2009-11-25 16:23:41Z henrib $ 036 */ 037 public interface Expression { 038 /** 039 * Evaluates the expression with the variables contained in the 040 * supplied {@link JexlContext}. 041 * 042 * @param context A JexlContext containing variables. 043 * @return The result of this evaluation 044 * @throws JexlException on any error 045 */ 046 Object evaluate(JexlContext context); 047 048 /** 049 * Returns the JEXL expression this Expression was created with. 050 * 051 * @return The JEXL expression to be evaluated 052 */ 053 String getExpression(); 054 055 /** 056 * Returns the JEXL expression by reconstructing it from the parsed tree. 057 * @return the JEXL expression 058 */ 059 String dump(); 060 }