JDK6.0学习笔记（十三）nio开发

1. /**
2.  * nio开发
3.  * 通过参数指定的主机端口发送一段请求报文，然后读取和打印报文
4.  * 需要接受主机名和监听端口作为输入参数
5.  * */
7. import java.io.IOException;
8. import java.net.UnknownHostException;
9. import java.net.InetSocketAddress;
10. import java.nio.ByteBuffer;
11. import java.nio.CharBuffer;
12. import java.nio.channels.SocketChannel;
13. import java.nio.charset.Charset;
14. import java.nio.charset.CharsetDecoder;
15. import java.nio.charset.CharsetEncoder;
17. public class ReadURL {
18.     public static void main(String args[]) {
19.         String host = args[0];
20.         int port = Integer.parseInt(args[1]);
21.         SocketChannel channel = null;
23.         try {
24.             // Setup
25.             InetSocketAddress socketAddress = new InetSocketAddress(host, port);
26.             Charset charset = Charset.forName("UTF-8");
27.             CharsetDecoder decoder = charset.newDecoder();
28.             CharsetEncoder encoder = charset.newEncoder();
30.             // Allocate buffers
31.             ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
32.             CharBuffer charBuffer = CharBuffer.allocate(1024);
34.             // Connect
35.             channel = SocketChannel.open();
36.             channel.connect(socketAddress);
38.             // Send request
39.             String request = "GET / \r\n\r\n";
40.             channel.write(encoder.encode(CharBuffer.wrap(request)));
42.             // Read response
43.             while ((channel.read(buffer)) != -1) {
44.                 buffer.flip();
45.                 // Decode buffer
46.                 decoder.decode(buffer, charBuffer, false);
47.                 // Display
48.                 charBuffer.flip();
49.                 System.out.println(charBuffer);
50.                 buffer.clear();
51.                 charBuffer.clear();
52.             }
53.         } catch (UnknownHostException e) {
54.             System.err.println(e);
55.         } catch (IOException e) {
56.             System.err.println(e);
57.         } finally {
58.             if (channel != null) {
59.                 try {
60.                     channel.close();
61.                 } catch (IOException ignored) {
62.                 }
63.             }
64.         }
65.     }
66. }