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 */ 017package org.apache.activemq.filter.function; 018 019import org.apache.activemq.filter.FunctionCallExpression; 020import org.apache.activemq.filter.MessageEvaluationContext; 021 022/** 023 * Function which replaces regular expression matches in a source string to a replacement literal. 024 * <p/> 025 * For Example: 026 * REPLACE('1,2/3', '[,/]', ';') returns '1;2;3' 027 */ 028 029public class replaceFunction implements FilterFunction { 030 /** 031 * Check whether the given expression is valid for this function. 032 * 033 * @param expr - the expression consisting of a call to this function. 034 * @return true - if three arguments are passed to the function; false - otherwise. 035 */ 036 037 public boolean isValid(FunctionCallExpression expr) { 038 if (expr.getNumArguments() == 3) 039 return true; 040 041 return false; 042 } 043 044 045 /** 046 * Indicate that this function does not return a boolean value. 047 * 048 * @param expr - the expression consisting of a call to this function. 049 * @return false - this filter function always evaluates to a string. 050 */ 051 052 public boolean returnsBoolean(FunctionCallExpression expr) { 053 return false; 054 } 055 056 057 /** 058 * Evaluate the given expression for this function in the given context. The result of the evaluation is a 059 * string with all matches of the regular expression, from the evaluation of the second argument, replaced by 060 * the string result from the evaluation of the third argument. Replacement is performed by 061 * String#replaceAll(). 062 * <p/> 063 * Note that all three arguments must be Strings. 064 * 065 * @param expr - the expression consisting of a call to this function. 066 * @return String - the result of the replacement. 067 */ 068 069 public Object evaluate(FunctionCallExpression expr, MessageEvaluationContext message_ctx) 070 throws javax.jms.JMSException { 071 String src; 072 String match_regex; 073 String repl_lit; 074 String result; 075 076 src = (String) expr.getArgument(0).evaluate(message_ctx); 077 match_regex = (String) expr.getArgument(1).evaluate(message_ctx); 078 repl_lit = (String) expr.getArgument(2).evaluate(message_ctx); 079 080 result = src.replaceAll(match_regex, repl_lit); 081 082 return result; 083 } 084}