udpserver.java

java入门经典教程 java入门经典教程 java入门经典教程

// 例8.3.2 UDPServer.java
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

public class UDPServer
{
	public static void main(String[] args)
	{
		try
		{
	     //创建一个DatagramSocket对象,指定端口号为8080,抛出SocketException
			DatagramSocket datagramSocket = new DatagramSocket(8080);
			
			String string = null;
			byte[] buffer = new byte[1024];
			
	//创建一个用来接收数据报的DatagramPacket对象，抛出UnknownHostException
			DatagramPacket datagramPacket = new DatagramPacket(buffer, 1024);

	//从网络中接收到一个数据报并放入指定的DatagramPacket中，抛出IOException
			datagramSocket.receive(datagramPacket);

	//从DatagramPacket中获取数据，并将其转换成字符串
string = new String(datagramPacket.getData(), 0, datagramPacket.getLength());
			System.out.println(string);
			
			// 关闭套接字，抛出IOException
			datagramSocket.close();
		} catch (SocketException es) {
			es.printStackTrace();
		} catch (IOException ex) {
			ex.printStackTrace();
		}
	}
}