java UDP传输

TCP通过 ServerSocket 和 Socket 来实现传输
UDP主要通过 DatagramSocket 和 DatagramPacket 来完成传输
直接上代码
服务器端：
public class UdpServer
{
private DatagramSocket server;
private DatagramPacket packet;
private byte[] b;
private String str;
public UdpServer()
{
Init();
}
private void Init()
{

b = new byte[1024];

receive();
}
private void receive()
{
try
{
server=new DatagramSocket(11111); //绑定11111端口
while(true)
{
packet = new DatagramPacket(b, b.length);
server.receive(packet); //接收数据包
int i = packet.getLength();
if(i>0) //数据包有内容，就打印出接收到的数据
{
str = new String(b, 0, i);
System.out.println("接收到的字符 == " + str);
packet = null;
}
}
}catch(SocketException e)
{
e.printStackTrace();
}catch(IOException e)
{
e.printStackTrace();
}finally
{
server.close();
}
}
public static void main(String[] args)
{
new UdpServer();
}
}
客户端：
public class UdpClient
{
private DatagramSocket client;
private DatagramPacket packet;
private byte b[];
public UdpClient()
{
Init();
}
private void Init()
{
b = new byte[1024];

send();
}
private void send()
{
try
{
client = new DatagramSocket();

b = "UDP数据发送".getBytes(); //发送给服务器端的数据

packet = new DatagramPacket(b, b.length, new InetSocketAddress("127.0.0.1", 11111)); //绑定服务器
client.send(packet); //发送数据包
} catch (SocketException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
} finally
{
client.close();
}
}
public static void main(String[] args)
{
new UdpClient();
}
}