Question

怎么了家伙。我在这里遇到了问题。文件正在运行但存在逻辑错误。我将我的Android应用程序连接到这个java应用程序。我试图在JFrame列表中发送多条消息，但是在JFrame运行时它没有显示。它就像这样

（JFRAME仍然没有显示）我连接到java app

（JFRAME仍然没有显示）发送一些消息，它在println中显示然后我关闭我的Android应用程序

JFrame从java app显示我发送的消息。（消息存储在JList中）

我希望它像是，当JFrame显示时，我想要追加Jlist中的值。请参阅此代码。这是使用

的代码

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import javax.swing.JList;


public class frmTestList extends JFrame {
public static final int portNumber = 60123;
private JPanel contentPane;
 static String data;
 static DefaultListModel model = new DefaultListModel();
/**
 * Launch the application.
 */
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {

             frmTestList frame = new frmTestList();
                frame.setVisible(true);
                try {


                     ServerSocket serverSocket = null;
                    serverSocket = new ServerSocket(portNumber);
                    Socket socket = serverSocket.accept();
                     BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

                       while((data = br.readLine()) != null ){

                        System.out.println("Message from the client: " + data);
                        model.addElement(data);
                       }
                } catch (Exception e) {
                    e.printStackTrace();
                }
        }
    });
}

/**
 * Create the frame.
 */
public frmTestList() {


    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 450, 300);
    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    contentPane.setLayout(new BorderLayout(0, 0));
    setContentPane(contentPane);

    JList list = new JList(model);
    contentPane.add(list, BorderLayout.CENTER);


}




}

Android代码：

import android.app.Activity;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class MainActivity extends Activity {

Socket socket = null;
public String debuggingString = "DEBUG";
public String hostname = ""; // <-- my ipv4 is here
public int portNumber = 60123;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    new Thread() {
        @Override
        public void run() {

            try {
                //connecting
                Log.e(debuggingString, "Attempting to connect to server");
                socket = new Socket(hostname, portNumber);

                //Send message to server
                BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
                bw.write("this is a message from the client");
                bw.newLine();
                bw.flush();

                //Receive message from server
                BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                System.out.println("Message from server: " + br.readLine());
            } catch (
                    Exception e
                    )

            {
                Log.e(debuggingString, e.getMessage());
            }
        }

    }.start();
}

;

public void sendMessage(View v) {
    EditText editText = (EditText) findViewById(R.id.editText);

    BufferedWriter bw = null;

    try {
        bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
        bw.write(editText.getText().toString());
        bw.newLine();
        bw.flush();
    } catch (Exception e) {
        Log.e(debuggingString, e.getMessage());
    }
}
}

先谢谢你们！

Answer 1

更新：进一步思考后，我猜：你的问题可能是

A）您的服务器位于那里并等待来自客户端的输入。含义：它循环播放＆＃34;新输入＆＃34; ...可能直到客户关闭连接。

和/或

B）你的＆＃34;服务器＆＃34;尝试在接受的同一个线程内更新UI。所以，试试：

 BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
 String line = null;
 while( (line = br.readLine() ) != null) {
   System.out.println("Message from server: " + br.readLine());
   EventQueue.invokeLater(new Runnable() {
     public void run() {
      model.addElement(line);
   }

最后：如果这些想法没有成功;你应该退一步 - 通过简化设置（通过将Android从图片中删除）：在JFrame中创建客户端套接字，同时让一个进程成为客户端/服务器。这将使调试/实验更容易。只有当它工作时，将客户端...移动到另一个JVM，然后移动到＆＃34; Android＆＃34;。

换句话说：退一步，从一个非常简单的客户端/服务器测试开始，该测试可以在一个类中完成所有操作。如果有效，继续前进。

Answer 2

您的JFrame未显示的原因是您从Event Dispatching Thread执行所有套接字读取。这样做会锁定所有UI更新。将套接字读取操作移动到其自己的Thread，并在更新JList模型时调用invokeLater。

public static void main(String[] args) {
    frmTestList frame = new frmTestList();

    EventQueue.invokeLater(new Runnable() {
        public void run() {
            frame.setVisible(true);
        }
    });

    Runnable runnable = new Runnable() {
        public void run() {
             try {
                 ServerSocket serverSocket = new ServerSocket(portNumber);
                 Socket socket = serverSocket.accept();
                 BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

                 while((data = br.readLine()) != null ) {
                     EventQueue.invokeLater(new Runnable() {
                         public void run() {
                             model.addElement(data);
                         }
                     });
                 }
             } catch (Exception e) {
                e.printStackTrace();
             } 
        }
    };
    new Thread(runnable).start();
}

运行“while”循环后，我的JFrame出现了。我希望JFrame在运行时显示

2 个答案: