/*
* Copyright 2004-2005 the original author or authors.
*
* Licensed 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.springmodules.validation.valang.functions;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;
/**
* Regular expression match function. Takes two arguments: the pattern as a string and the string
* to be matched. The toString method of the second parameter value is called to retrieve the
* string value. This function is not null-safe.
*
* @author Steven Devijver
* @since Sep 15, 2005
*/
public class RegExFunction extends AbstractFunction {
private Map patternCache = null;
public RegExFunction(Function[] arguments, int line, int column) {
super(arguments, line, column);
definedExactNumberOfArguments(2);
patternCache = new HashMap();
}
protected Object doGetResult(Object target) throws Exception {
Object value = getArguments()[0].getResult(target);
if (value instanceof String) {
Pattern pattern = null;
if (patternCache.containsKey(value)) {
pattern = (Pattern) patternCache.get(value);
} else {
pattern = Pattern.compile((String) value);
patternCache.put(value, pattern);
}
String str = getArguments()[1].getResult(target).toString();
return pattern.matcher(str).matches() ? Boolean.TRUE : Boolean.FALSE;
} else {
throw new Exception("No String value for regular expression");
}
}
}