客戶機程式

import java.net.*;
import java.io.*;
public class SClient {
 public static void main(String args[])
 {
String s=null;
Socket c_socket;
DataInputStream in=null;
DataOutputStream out=null;
 
try{
c_socket=new Socket("localhost",4321);     //執行到這裡，立即向伺服器發起連線
in=new DataInputStream(c_socket.getInputStream());
out=new DataOutputStream(c_socket.getOutputStream());
while(true)   //通過迴圈，讀取資料輸入流讀取伺服器放在“線路”裡的資訊
{
s=in.readUTF();
if(s!=null) break;
}
out.writeUTF("我是客戶機，收到你返回的資訊！");
c_socket.close();
}
catch(IOException e){
s="無法連線";  
}
System.out.println("客戶機收到 :"+s);
 }
}
 

import java.io.*;
import java.net.*;
public class SServer {
 public static void main(String args[])
 {
ServerSocket s_socket=null;
Socket socket=null;
String s=null;
DataOutputStream out=null;
DataInputStream in=null;
 
try{
s_socket=new ServerSocket(4321); 
}catch(IOException e1){
System.out.println("ERROR:"+e1);
}
try{
socket=s_socket.accept();
in=new DataInputStream(socket.getInputStream());
out=new DataOutputStream(socket.getOutputStream());
out.writeUTF("你好，我是伺服器，連線成功！");
while(true)  //通過迴圈，通過資料輸入流，讀取客戶機放在“線路”裡的資訊
{
s=in.readUTF();
if(s!=null) break;
}
System.out.println("伺服器收到："+s);
socket.close();
}catch(IOException e)
{
System.out.println("ERROR "+e);
}
 
 }
}