Question

当用户按下Enter键时，当前行被发送到客户端。客户端有两个文本区域：一个用于接收来自服务器的文本，另一个用于输入文本。当用户按Enter键，当前行被发送到服务器。

当我运行程序时，客户端和服务器没有发送任何东西为什么??可以帮助吗？

client.java
package sheet4_q7_client;
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;

public class Sheet4_Q7_Client extends JFrame{
String s="";
/**
 * @param args the command line arguments
 */
private JTextArea jtaServer = new JTextArea();

// Text area for displaying client text
private JTextArea jtaClient = new JTextArea();

private PrintWriter output,output1,output2;

public static void main(String[] args) {
new Sheet4_Q7_Client();
}

public Sheet4_Q7_Client() {

// Place text area on the frame
setLayout(new GridLayout(2, 1));
JScrollPane jScrollPane1 = new JScrollPane(jtaServer);
JScrollPane jScrollPane2 = new JScrollPane(jtaClient);
jScrollPane1.setBorder(new TitledBorder("Server"));
jScrollPane2.setBorder(new TitledBorder("Client"));
add(jScrollPane2, BorderLayout.CENTER);
add(jScrollPane1, BorderLayout.CENTER);

jtaServer.setWrapStyleWord(true);
jtaServer.setLineWrap(true);
jtaClient.setWrapStyleWord(true);
jtaClient.setLineWrap(true);
//    jtaClient.setEditable(false);

setTitle("Exercise30_12Client");
setSize(500, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null); // Center the frame
setVisible(true); // It is necessary to show the frame here!

try {
  // Create a server socket
  Socket connectToServer = new Socket("localhost", 8000);

  //output = new
    //PrintWriter(connectToServer.getOutputStream());
  new SendThread(connectToServer).start();
  new ReceiveThread(connectToServer).start();
}
catch(IOException ex) {
  System.err.println(ex);
}

jtaServer.addKeyListener(new KeyAdapter() {
  public void keyPressed(KeyEvent e) {
     if (e.getKeyCode() == e.VK_BACK_SLASH) {
     s=jtaServer.getText().toString();

    }
  }
 });
}

class SendThread extends Thread  {
SendThread(Socket socket) {
  // Keep sending to the client
    try {
        output1 = new PrintWriter(socket.getOutputStream());
        output1.write(s);
        output1.flush();
    }
    catch(IOException ex) {
  System.err.println(ex);
        }
}
}

class ReceiveThread extends Thread {
 ReceiveThread(Socket socket) {
  // Keep receiving from the client
     try {
       Scanner input1 = new Scanner(socket.getInputStream());
        String s1=input1.nextLine();
        jtaServer.setText(s1);
    }
    catch(IOException ex) {
  System.err.println(ex);
        }
 }
 }
 }

server.java

package sheet4_q7_server;
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;

public class Sheet4_Q7_Server extends JFrame{
    String s="";
/**
 * @param args the command line arguments
 */
private JTextArea jtaServer = new JTextArea();

// Text area for displaying client text
private JTextArea jtaClient = new JTextArea();

private PrintWriter output,output1;

public static void main(String[] args) {
new Sheet4_Q7_Server();
}

public Sheet4_Q7_Server() {
// Place text area on the frame
setLayout(new GridLayout(2, 1));
JScrollPane jScrollPane1 = new JScrollPane(jtaServer);
JScrollPane jScrollPane2 = new JScrollPane(jtaClient);
jScrollPane1.setBorder(new TitledBorder("Server"));
jScrollPane2.setBorder(new TitledBorder("Client"));
add(jScrollPane1, BorderLayout.CENTER);
add(jScrollPane2, BorderLayout.CENTER);

jtaServer.setWrapStyleWord(true);
jtaServer.setLineWrap(true);
jtaClient.setWrapStyleWord(true);
jtaClient.setLineWrap(true);
//    jtaClient.setEditable(false);

setTitle("Exercise30_12Server");
setSize(500, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null); // Center the frame
setVisible(true); // It is necessary to show the frame here!

try {
  // Create a server socket
  ServerSocket serverSocket = new ServerSocket(8000);

  // Listen for a new connection request
  Socket connectToClient = serverSocket.accept();
  output = new
    PrintWriter(connectToClient.getOutputStream());
  new SendThread(connectToClient).start();
  new ReceiveThread(connectToClient).start();
}
catch(IOException ex) {
  System.err.println(ex);
}

jtaServer.addKeyListener(new KeyAdapter() {
  public void keyPressed(KeyEvent e) {
    if (e.getKeyCode() == e.VK_ENTER) {
      s=jtaServer.getText().toString();
      //System.out.print(s);
    }
  }
 });
 }

class SendThread extends Thread {
SendThread(Socket socket) {
  // Keep sending to the client
    try {
        output1 = new PrintWriter(socket.getOutputStream());
        output1.write(s);
        output1.flush();

    }
    catch(IOException ex) {
  System.err.println(ex);
        }
 }
 }

class ReceiveThread extends Thread {
ReceiveThread(Socket socket) {
  // Keep receiving from the client
    try {
       Scanner input1 = new Scanner(socket.getInputStream());
        String s1=input1.nextLine();
        jtaClient.setText(s1);
    }
    catch(IOException ex) {
  System.err.println(ex);
        }
}
}
}

Answer 1

看起来你发送和接收线程正在构造函数中执行它们的功能。

尝试改写run方法。

您可能还想在while循环中执行此操作，否则它只会执行一次。

在java中写一个程序，使两个用户可以聊天。

1 个答案: