1 /*
2 * Copyright 2004-2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springmodules.validation.valang.functions;
18
19 import java.util.HashMap;
20 import java.util.Map;
21 import java.util.regex.Pattern;
22
23 /**
24 * Regular expression match function. Takes two arguments: the pattern as a string and the string
25 * to be matched. The toString method of the second parameter value is called to retrieve the
26 * string value. This function is not null-safe.
27 *
28 * @author Steven Devijver
29 * @since Sep 15, 2005
30 */
31 public class RegExFunction extends AbstractFunction {
32
33 private Map patternCache = null;
34
35 public RegExFunction(Function[] arguments, int line, int column) {
36 super(arguments, line, column);
37 definedExactNumberOfArguments(2);
38 patternCache = new HashMap();
39 }
40
41 protected Object doGetResult(Object target) throws Exception {
42 Object value = getArguments()[0].getResult(target);
43 if (value instanceof String) {
44 Pattern pattern = null;
45 if (patternCache.containsKey(value)) {
46 pattern = (Pattern) patternCache.get(value);
47 } else {
48 pattern = Pattern.compile((String) value);
49 patternCache.put(value, pattern);
50 }
51 String str = getArguments()[1].getResult(target).toString();
52 return pattern.matcher(str).matches() ? Boolean.TRUE : Boolean.FALSE;
53 } else {
54 throw new Exception("No String value for regular expression");
55 }
56 }
57
58 }