java TCP和UDP 连接

我们先来讲讲UDP的连接

UDP分 发送端和接收端

UDP发送端(利用线程处理)

import java.io.*;
import java,net.*;

public class Send implements Runnable
{
private DatagramSocket ds;
public Send(DatagramSokcet ds)
{
this.ds=ds;
}
public void run()
{
try{
BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in));
String line = null;
while((line=bufr.readline())!=null)
{
byte[] buf = line.getBytes();
DatagramPacket dp = new DatagramPacket(buf,buf.length,InetAddress.getByName("127.0.0.1"),10000);
ds.send(dp);
if("over".equals(line))
break;

}
ds.close();
}catch(Exception e){}
}
}

UDP接收端

import java.io.*;
import java.net.*;
public class Rece implements Runnable
{
private DatagramSocket ds;
public Rece(DatagramSocket ds)
{
this.ds=ds;
}
public void run()
{
try{
while(true)
{
byte[] buf = new byte[1024];
DatagramPacket dp = new DatagramPacket(buf,buf.length);
ds.receive(dp);
String ip = dp.getAddress().getHostAddress();
int port = dp.getPort();
String text = new String (dp.getData(),0,dp.getLength());
if(text.equals("over"))
{
System.out.println(ip+"...退出"));
}
System.out.println(ip+":"+port+":"+text);
}
}catch(Exception e){}
}
}

总结： UDP连接是不安全的 且发送的数据有大小的限制

TCP连接：

TCP分服务端和客户端

最大的区别是服务端有ServerSocket Socket

而客户端只有Socket

先建立连接 才能传输数据至服务端