Package: ListensTo

ListensTo

Coverage

1: /*
2: * *********************************************************************************************************************
3: *
4: * TheseFoolishThings: Miscellaneous utilities
5: * http://tidalwave.it/projects/thesefoolishthings
6: *
7: * Copyright (C) 2009 - 2024 by Tidalwave s.a.s. (http://tidalwave.it)
8: *
9: * *********************************************************************************************************************
10: *
11: * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
12: * the License. You may obtain a copy of the License at
13: *
14: * http://www.apache.org/licenses/LICENSE-2.0
15: *
16: * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
17: * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
18: * specific language governing permissions and limitations under the License.
19: *
20: * *********************************************************************************************************************
21: *
22: * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
23: * git clone https://github.com/tidalwave-it/thesefoolishthings-src
24: *
25: * *********************************************************************************************************************
26: */
27: package it.tidalwave.messagebus.annotation;
28:
29: import java.lang.annotation.Documented;
30: import java.lang.annotation.ElementType;
31: import java.lang.annotation.Retention;
32: import java.lang.annotation.RetentionPolicy;
33: import java.lang.annotation.Target;
34:
35: /***********************************************************************************************************************
36: *
37: * This annotation is used to write simpler code which uses a message bus. With the proper support, code that receives
38: * messages can be written as simple methods such as:
39: *
40: * <pre>
41: * private void onMessage (final @ListenTo Message message)
42: * {
43: * ...
44: * }
45: * </pre>
46: *
47: * Note that this annotation doesn't support any further semantics; for instance, <code>message</code> could be null or
48: * not, in function of the message bus implementation; nor you can make any assumption on the threading. The exact
49: * semantics are defined by further annotations (on the class containing the listener method), or by the build context
50: * (e.g. an annotation processor, AspectJ, etc...).
51: *
52: * Specific support must be used in order to have this annotation working. For instance, an annotation processor, or
53: * some facility which scans classes at runtime, or {@link it.tidalwave.messagebus.MessageBusHelper}.
54: *
55: * @author Fabrizio Giudici
56: *
57: **********************************************************************************************************************/
58: @Retention(RetentionPolicy.RUNTIME)
59: @Target(ElementType.PARAMETER)
60: @Documented
61: public @interface ListensTo
62: {
63: }