本文实例讲述了Java使用Socket通信传输文件的方法。分享给大家供大家参考,具体如下:
前面几篇文章介绍了使用Java的Socket编程和NIO包在Socket中的应用,这篇文章说说怎样利用Socket编程来实现简单的文件传输。
这里由于前面一片文章介绍了NIO在Socket中的应用,所以这里在读写文件的时候也继续使用NIO包,所以代码看起来会比直接使用流的方式稍微复杂一点点。
下面的示例演示了客户端向服务器端发送一个文件,服务器作为响应给客户端回发一个文件。这里准备两个文件E:/test/server_send.log和E:/test/client.send.log文件,在测试完毕后在客户端和服务器相同目录下会多出两个文件E:/test/server_receive.log和E:/test/client.receive.log文件。
下面首先来看看Server类,主要关注其中的sendFile和receiveFile方法。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
package com.googlecode.garbagecan.test.socket.nio; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.ClosedChannelException; import java.nio.channels.FileChannel; import java.nio.channels.SelectionKey; import java.nio.channels.Selector; import java.nio.channels.ServerSocketChannel; import java.nio.channels.SocketChannel; import java.util.Iterator; import java.util.logging.Level; import java.util.logging.Logger; public class MyServer4 { private final static Logger logger = Logger.getLogger(MyServer4. class .getName()); public static void main(String[] args) { Selector selector = null ; ServerSocketChannel serverSocketChannel = null ; try { // Selector for incoming time requests selector = Selector.open(); // Create a new server socket and set to non blocking mode serverSocketChannel = ServerSocketChannel.open(); serverSocketChannel.configureBlocking( false ); // Bind the server socket to the local host and port serverSocketChannel.socket().setReuseAddress( true ); serverSocketChannel.socket().bind( new InetSocketAddress( 10000 )); // Register accepts on the server socket with the selector. This // step tells the selector that the socket wants to be put on the // ready list when accept operations occur, so allowing multiplexed // non-blocking I/O to take place. serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); // Here's where everything happens. The select method will // return when any operations registered above have occurred, the // thread has been interrupted, etc. while (selector.select() > 0 ) { // Someone is ready for I/O, get the ready keys Iterator<SelectionKey> it = selector.selectedKeys().iterator(); // Walk through the ready keys collection and process date requests. while (it.hasNext()) { SelectionKey readyKey = it.next(); it.remove(); // The key indexes into the selector so you // can retrieve the socket that's ready for I/O doit((ServerSocketChannel) readyKey.channel()); } } } catch (ClosedChannelException ex) { logger.log(Level.SEVERE, null , ex); } catch (IOException ex) { logger.log(Level.SEVERE, null , ex); } finally { try { selector.close(); } catch (Exception ex) {} try { serverSocketChannel.close(); } catch (Exception ex) {} } } private static void doit( final ServerSocketChannel serverSocketChannel) throws IOException { SocketChannel socketChannel = null ; try { socketChannel = serverSocketChannel.accept(); receiveFile(socketChannel, new File( "E:/test/server_receive.log" )); sendFile(socketChannel, new File( "E:/test/server_send.log" )); } finally { try { socketChannel.close(); } catch (Exception ex) {} } } private static void receiveFile(SocketChannel socketChannel, File file) throws IOException { FileOutputStream fos = null ; FileChannel channel = null ; try { fos = new FileOutputStream(file); channel = fos.getChannel(); ByteBuffer buffer = ByteBuffer.allocateDirect( 1024 ); int size = 0 ; while ((size = socketChannel.read(buffer)) != - 1 ) { buffer.flip(); if (size > 0 ) { buffer.limit(size); channel.write(buffer); buffer.clear(); } } } finally { try { channel.close(); } catch (Exception ex) {} try { fos.close(); } catch (Exception ex) {} } } private static void sendFile(SocketChannel socketChannel, File file) throws IOException { FileInputStream fis = null ; FileChannel channel = null ; try { fis = new FileInputStream(file); channel = fis.getChannel(); ByteBuffer buffer = ByteBuffer.allocateDirect( 1024 ); int size = 0 ; while ((size = channel.read(buffer)) != - 1 ) { buffer.rewind(); buffer.limit(size); socketChannel.write(buffer); buffer.clear(); } socketChannel.socket().shutdownOutput(); } finally { try { channel.close(); } catch (Exception ex) {} try { fis.close(); } catch (Exception ex) {} } } } |
下面是Client程序代码,也主要关注sendFile和receiveFile方法
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
package com.googlecode.garbagecan.test.socket.nio; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; import java.nio.channels.SocketChannel; import java.util.logging.Level; import java.util.logging.Logger; public class MyClient4 { private final static Logger logger = Logger.getLogger(MyClient4. class .getName()); public static void main(String[] args) throws Exception { new Thread( new MyRunnable()).start(); } private static final class MyRunnable implements Runnable { public void run() { SocketChannel socketChannel = null ; try { socketChannel = SocketChannel.open(); SocketAddress socketAddress = new InetSocketAddress( "localhost" , 10000 ); socketChannel.connect(socketAddress); sendFile(socketChannel, new File( "E:/test/client_send.log" )); receiveFile(socketChannel, new File( "E:/test/client_receive.log" )); } catch (Exception ex) { logger.log(Level.SEVERE, null , ex); } finally { try { socketChannel.close(); } catch (Exception ex) {} } } private void sendFile(SocketChannel socketChannel, File file) throws IOException { FileInputStream fis = null ; FileChannel channel = null ; try { fis = new FileInputStream(file); channel = fis.getChannel(); ByteBuffer buffer = ByteBuffer.allocateDirect( 1024 ); int size = 0 ; while ((size = channel.read(buffer)) != - 1 ) { buffer.rewind(); buffer.limit(size); socketChannel.write(buffer); buffer.clear(); } socketChannel.socket().shutdownOutput(); } finally { try { channel.close(); } catch (Exception ex) {} try { fis.close(); } catch (Exception ex) {} } } private void receiveFile(SocketChannel socketChannel, File file) throws IOException { FileOutputStream fos = null ; FileChannel channel = null ; try { fos = new FileOutputStream(file); channel = fos.getChannel(); ByteBuffer buffer = ByteBuffer.allocateDirect( 1024 ); int size = 0 ; while ((size = socketChannel.read(buffer)) != - 1 ) { buffer.flip(); if (size > 0 ) { buffer.limit(size); channel.write(buffer); buffer.clear(); } } } finally { try { channel.close(); } catch (Exception ex) {} try { fos.close(); } catch (Exception ex) {} } } } } |
首先运行MyServer4类启动监听,然后运行MyClient4类来向服务器发送文件以及接受服务器响应文件。运行完后,分别检查服务器和客户端接收到的文件。
希望本文所述对大家java程序设计有所帮助。