線程之間的通信？

Question

獲得了2個線程的程序。一個線程正在寫入一些東西到控制檯中。

public class Konsole extends Thread { 

    static int id = 0; 

    Client client; 

    public Konsole(Client client) { 
     this.client = client; 
    } 

    public void run() { 
     System.out.println("========= Konsole "+ ++id +" started"); 

    while(true) { 


     try { 

      String line = client.fromServer.readLine(); 

      client.commands.add(line); 
       System.out.println(line); 

       if(line == null) {break;} 


     } catch (IOException e) {} 

    } 

在Client類中退出公共靜態堆棧。 但是堆棧總是空的，Konsole無法訪問堆棧。 有人可以給我一個提示，爲什麼？

Client類

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.io.PrintWriter; 
import java.net.Socket; 
import java.net.UnknownHostException; 
import java.util.Stack; 
import java.util.StringTokenizer; 


public class Client extends Thread { 

    // Verbindungsvariablen 
    final String user = "user"; 
    final String pass = "pass"; 
    public String host = "localhost"; 
    int port = 21; 


    // PASV 
    int portNew; 
    String ipNew = ""; 

    public static Stack<String> commands = new Stack<String>(); 

    boolean lastCommand = false; 

    // Sockets 
    Socket serverSocket; 
    Socket pasvSocket; 
    PrintWriter writeCommands; 
    BufferedReader fromServer; 

    PrintWriter writePasvCommands; 
    BufferedReader fromPasvServer; 

    // Baut die Verbindung auf 
    public void connect() throws IOException { 

     try { 
      serverSocket = new Socket(host, port); 
      System.out.println("Baue Verbindung auf ..."); 
      fromServer = new BufferedReader(new InputStreamReader(
        serverSocket.getInputStream())); 
      writeCommands = new PrintWriter(serverSocket.getOutputStream(), 
        true); 
     } catch (UnknownHostException e) { 
      System.out.println("Host unbekannt!"); 
      e.printStackTrace(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

    } 

    public void USER() throws IOException { 
     writeCommands.print("USER " + user + "\n"); 
     writeCommands.flush(); 
    } 

    public void PASS() { 
     writeCommands.print("PASS " + pass +"\n"); 
     writeCommands.flush(); 
    } 

    public void NOOP() { 
     writeCommands.print("NOOP\n"); 
     writeCommands.flush(); 
    } 

    public void getStatus() { 
     Thread konsole = new Thread(new Konsole(this)); 
     konsole.start(); 
    } 

    // PASV anschalten 
    public void PASV() throws IOException, InterruptedException { 

     writeCommands.print("PASV\n"); 
     writeCommands.flush(); 
     //getPasvCon(); 


    } 
public void getPasvCon() throws IOException, InterruptedException { 
     System.out.println("!!!!!!"); 
     // Commands abholen 


     // IP Adresse holen 

     String pasv = commands.lastElement(); 
     String ipAndPort = pasv.substring(pasv.indexOf("(") + 1, 
       pasv.indexOf(")")); 

     StringTokenizer getIp = new StringTokenizer(ipAndPort); 

     // holt die IP 
     String ipNew = ""; // IP für den neuen Socket 
     for (int i = 0; i < 4; i++) { 
      if (i < 3) { 
       ipNew += (getIp.nextToken(",") + "."); 
      } else { 
       ipNew += (getIp.nextToken(",")); 

      } 
     } 


     Integer portTemp1 = new Integer(getIp.nextToken(",")); 
     Integer portTemp2 = new Integer (getIp.nextToken(",")); 
     portNew = (portTemp1 << 8)+ portTemp2; 


     try { 

      pasvSocket = new Socket(ipNew, portNew); 

     } catch (UnknownHostException e) { 
      System.out.println("Host unbekannt"); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     try { 
      fromPasvServer = new BufferedReader(new InputStreamReader(
        pasvSocket.getInputStream())); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     try { 
      writePasvCommands = new PrintWriter(pasvSocket.getOutputStream(), 
        true); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 




    } 

    public void LIST() throws IOException { 
    writeCommands.print("LIST\n"); 
    writeCommands.flush(); 

    } 


    public void run() { 
     try { 
      connect(); 

    //  getStatus(); 

     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     try { 
      USER(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     PASS(); 


     try { 
      PASV(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (InterruptedException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
    } 

    public Client() throws IOException { 

    } 



    public static void main(String[] args) throws IOException, InterruptedException { 
     Client test = new Client(); 
     Thread client = new Thread(test); 
     client.start(); 

     Thread.sleep(300); 


     Thread konsole = new Thread(new Konsole(test)); 
     konsole.start(); 



     Disrupter disrupt = new Disrupter(test); 
     disrupt.start(); 



    } 



} 

（靜態是毫無意義的，是不是？）

Answer 1

曾與Thread.sleep（）方法。感謝所有。