Java 新手 Socket问题 求帮助

//SocketDemo客户端部分
import java.io.*;
import java.net.*;
public class SocketDemo{
   Socket socket;
   BufferedReader bufferedreader,in;
   PrintStream printstream;
   public SocketDemo(){
      try{
      socket=new Socket("127.0.0.1",8888);
      bufferedreader=new BufferedReader(new InputStreamReader(socket.getInputStream()));
      printstream=new PrintStream(socket.getOutputStream(),true);
      in=new BufferedReader(new InputStreamReader(System.in));
      while(true){
      String s=in.readLine();
      printstream.print(s);
      System.out.println(bufferedreader.readLine());
      printstream.close();
      in.close();
      bufferedreader.close();
      socket.close();
         Thread.sleep(500);
      }
      
      }
      catch(IOException e){
         e.printStackTrace();}
      catch(InterruptedException e){}
      }
     public static void main(String args[]){
      new SocketDemo();
      }
   }
//SeverSocketDemo服务器部分 
import java.io.*;
import java.net.*;
public class SeverSocketDemo{
   ServerSocket serversocket;
   Socket socket;
   BufferedReader bufferedreader;
   PrintStream printstream;
   public SeverSocketDemo(){
      try{
      serversocket=new ServerSocket(8888);
      socket=serversocket.accept();
      printstream=new PrintStream(socket.getOutputStream(),true);
      bufferedreader=new BufferedReader(new InputStreamReader(socket.getInputStream()));
      while(true){
         String string=bufferedreader.readLine();
         System.out.println(string);
         printstream.print("Your message is arrival");
        printstream.close();
         bufferedreader.close(); 
         socket.close();
         Thread.sleep(500);
         }
     
      }catch(IOException e){System.out.println("客户端已经断开"+e);}
       
       catch(InterruptedException e){System.out.println("线程出错");}
       }
      public static void main(String args[]){
         new SeverSocketDemo();
         } 
   }
      问题是为甚吗 服务器部分不显示 客户端的字符串呢？？？？？？