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 splits a string into a list of strings given a regular expression for the separator. 024 */ 025 026public class splitFunction implements FilterFunction { 027 /** 028 * Check whether the given expression is valid for this function. 029 * 030 * @param expr - the expression consisting of a call to this function. 031 * @return true - if two or three arguments are passed to the function; false - otherwise. 032 */ 033 034 public boolean isValid(FunctionCallExpression expr) { 035 if ((expr.getNumArguments() >= 2) && (expr.getNumArguments() <= 3)) 036 return true; 037 038 return false; 039 } 040 041 042 /** 043 * Indicate that this function does not return a boolean value. 044 * 045 * @param expr - the expression consisting of a call to this function. 046 * @return false - indicating this filter function never evaluates to a boolean result. 047 */ 048 049 public boolean returnsBoolean(FunctionCallExpression expr) { 050 return false; 051 } 052 053 054 /** 055 * Evaluate the given expression for this function in the given context. A list of zero or more strings 056 * results from the evaluation. The result of the evaluation of the first argument is split with the regular 057 * expression which results from the evaluation of the second argument. If a third argument is given, it 058 * is an integer which limits the split. String#split() performs the split. 059 * <p/> 060 * The first two arguments must be Strings. If a third is given, it must be an Integer. 061 * 062 * @param expr - the expression consisting of a call to this function. 063 * @return List - a list of Strings resulting from the split. 064 */ 065 066 public Object evaluate(FunctionCallExpression expr, MessageEvaluationContext message_ctx) 067 throws javax.jms.JMSException { 068 String src; 069 String split_pat; 070 String[] result; 071 072 src = (String) expr.getArgument(0).evaluate(message_ctx); 073 split_pat = (String) expr.getArgument(1).evaluate(message_ctx); 074 075 if (expr.getNumArguments() > 2) { 076 Integer limit; 077 078 limit = (Integer) expr.getArgument(2).evaluate(message_ctx); 079 080 result = src.split(split_pat, limit.intValue()); 081 } else { 082 result = src.split(split_pat); 083 } 084 085 return java.util.Arrays.asList(result); 086 } 087}