1/*
2 * Copyright (c) 2011 Oracle and/or its affiliates. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 *   - Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 *
11 *   - Redistributions in binary form must reproduce the above copyright
12 *     notice, this list of conditions and the following disclaimer in the
13 *     documentation and/or other materials provided with the distribution.
14 *
15 *   - Neither the name of Oracle nor the names of its
16 *     contributors may be used to endorse or promote products derived
17 *     from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * This source code is provided to illustrate the usage of a given feature
34 * or technique and has been deliberately simplified. Additional steps
35 * required for a production-quality application, such as security checks,
36 * input validation and proper error handling, might not be present in
37 * this sample code.
38 */
39
40
41import java.nio.ByteBuffer;
42import java.nio.channels.CompletionHandler;
43
44/**
45 * Handles a cycle of reading / writing on the {@code Client}.
46 */
47class ClientReader {
48    private final DataReader callback;
49    private final ChatServer chatServer;
50
51    ClientReader(ChatServer chatServer, DataReader callback) {
52        this.chatServer = chatServer;
53        this.callback = callback;
54    }
55
56    public boolean acceptsMessages() {
57        return callback.acceptsMessages();
58    }
59
60    /**
61     * Runs a cycle of doing a beforeRead action and then enqueuing a new
62     * read on the client. Handles closed channels and errors while reading.
63     * If the client is still connected a new round of actions are called.
64     */
65    public void run(final Client client) {
66        callback.beforeRead(client);
67        client.read(new CompletionHandler<Integer, ByteBuffer>() {
68            @Override
69            public void completed(Integer result, ByteBuffer buffer) {
70                // if result is negative or zero the connection has been closed or something gone wrong
71                if (result < 1) {
72                    client.close();
73                    System.out.println("Closing connection to " + client);
74                    chatServer.removeClient(client);
75                } else {
76                    callback.onData(client, buffer, result);
77                    // enqueue next round of actions
78                    client.run();
79                }
80            }
81
82            @Override
83            public void failed(Throwable exc, ByteBuffer buffer) {
84                client.close();
85                chatServer.removeClient(client);
86            }
87        });
88    }
89}
90