org.apache.activemq.filter.function.replaceFunction Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.activemq.filter.function;
import org.apache.activemq.filter.FunctionCallExpression;
import org.apache.activemq.filter.MessageEvaluationContext;
/**
* Function which replaces regular expression matches in a source string to a replacement literal.
*
* For Example:
* REPLACE('1,2/3', '[,/]', ';') returns '1;2;3'
*/
public class replaceFunction implements FilterFunction {
/**
* Check whether the given expression is valid for this function.
*
* @param expr - the expression consisting of a call to this function.
* @return true - if three arguments are passed to the function; false - otherwise.
*/
public boolean isValid(FunctionCallExpression expr) {
if (expr.getNumArguments() == 3)
return true;
return false;
}
/**
* Indicate that this function does not return a boolean value.
*
* @param expr - the expression consisting of a call to this function.
* @return false - this filter function always evaluates to a string.
*/
public boolean returnsBoolean(FunctionCallExpression expr) {
return false;
}
/**
* Evaluate the given expression for this function in the given context. The result of the evaluation is a
* string with all matches of the regular expression, from the evaluation of the second argument, replaced by
* the string result from the evaluation of the third argument. Replacement is performed by
* String#replaceAll().
*
* Note that all three arguments must be Strings.
*
* @param expr - the expression consisting of a call to this function.
* @return String - the result of the replacement.
*/
public Object evaluate(FunctionCallExpression expr, MessageEvaluationContext message_ctx)
throws javax.jms.JMSException {
String src;
String match_regex;
String repl_lit;
String result;
src = (String) expr.getArgument(0).evaluate(message_ctx);
match_regex = (String) expr.getArgument(1).evaluate(message_ctx);
repl_lit = (String) expr.getArgument(2).evaluate(message_ctx);
result = src.replaceAll(match_regex, repl_lit);
return result;
}
}