1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements.  See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License.  You may obtain a copy of the License at
8  *
9  *     http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 package nginx.unit.websocket.pojo;
18 
19 import java.lang.reflect.InvocationTargetException;
20 import java.lang.reflect.Method;
21 
22 import javax.websocket.DecodeException;
23 import javax.websocket.MessageHandler;
24 import javax.websocket.Session;
25 
26 import nginx.unit.websocket.WsSession;
27 
28 /**
29  * Common implementation code for the POJO whole message handlers. All the real
30  * work is done in this class and in the superclass.
31  *
32  * @param <T>   The type of message to handle
33  */
34 public abstract class PojoMessageHandlerWholeBase<T>
35         extends PojoMessageHandlerBase<T> implements MessageHandler.Whole<T> {
36 
PojoMessageHandlerWholeBase(Object pojo, Method method, Session session, Object[] params, int indexPayload, boolean convert, int indexSession, long maxMessageSize)37     public PojoMessageHandlerWholeBase(Object pojo, Method method,
38             Session session, Object[] params, int indexPayload,
39             boolean convert, int indexSession, long maxMessageSize) {
40         super(pojo, method, session, params, indexPayload, convert,
41                 indexSession, maxMessageSize);
42     }
43 
44 
45     @Override
onMessage(T message)46     public final void onMessage(T message) {
47 
48         if (params.length == 1 && params[0] instanceof DecodeException) {
49             ((WsSession) session).getLocal().onError(session,
50                     (DecodeException) params[0]);
51             return;
52         }
53 
54         // Can this message be decoded?
55         Object payload;
56         try {
57             payload = decode(message);
58         } catch (DecodeException de) {
59             ((WsSession) session).getLocal().onError(session, de);
60             return;
61         }
62 
63         if (payload == null) {
64             // Not decoded. Convert if required.
65             if (convert) {
66                 payload = convert(message);
67             } else {
68                 payload = message;
69             }
70         }
71 
72         Object[] parameters = params.clone();
73         if (indexSession != -1) {
74             parameters[indexSession] = session;
75         }
76         parameters[indexPayload] = payload;
77 
78         Object result = null;
79         try {
80             result = method.invoke(pojo, parameters);
81         } catch (IllegalAccessException | InvocationTargetException e) {
82             handlePojoMethodException(e);
83         }
84         processResult(result);
85     }
86 
convert(T message)87     protected Object convert(T message) {
88         return message;
89     }
90 
91 
decode(T message)92     protected abstract Object decode(T message) throws DecodeException;
onClose()93     protected abstract void onClose();
94 }
95