01: /*
02: * Copyright 2001-2004 The Apache Software Foundation
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
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: package org.apache.commons.collections.functors;
17:
18: import java.io.Serializable;
19:
20: import org.apache.commons.collections.Closure;
21: import org.apache.commons.collections.FunctorException;
22:
23: /**
24: * Closure implementation that always throws an exception.
25: *
26: * @since Commons Collections 3.0
27: * @version $Revision: 348444 $ $Date: 2005-11-23 14:06:56 +0000 (Wed, 23 Nov 2005) $
28: *
29: * @author Stephen Colebourne
30: */
31: public final class ExceptionClosure implements Closure, Serializable {
32:
33: /** Serial version UID */
34: private static final long serialVersionUID = 7179106032121985545L;
35:
36: /** Singleton predicate instance */
37: public static final Closure INSTANCE = new ExceptionClosure();
38:
39: /**
40: * Factory returning the singleton instance.
41: *
42: * @return the singleton instance
43: * @since Commons Collections 3.1
44: */
45: public static Closure getInstance() {
46: return INSTANCE;
47: }
48:
49: /**
50: * Restricted constructor.
51: */
52: private ExceptionClosure() {
53: super ();
54: }
55:
56: /**
57: * Always throw an exception.
58: *
59: * @param input the input object
60: * @throws FunctorException always
61: */
62: public void execute(Object input) {
63: throw new FunctorException("ExceptionClosure invoked");
64: }
65:
66: }
|