Question

我正在尝试通过LAN创建消息传递应用程序。在AppHost下，我正在为HostUI和HostConnect运行并发线程（一个用于显示UI，另一个用于接收/管理传入和传出连接）。我正在尝试将所有这些类编写为单例类。

我正在尝试使用JTextField(ipField)在HostUI setText()上显示服务器IP地址。然而，在setText()之后，尽管getText() ipField将返回新文本，但UI窗口不会显示更新的文本。

以下是三个类的代码：

APPHOST：

public class AppHost {
    public static AppHost instance;

    Thread[] threads = new Thread[2];
    final int CONNECTION = 0;
    final int UI = 1;
    ExecutorService executor = Executors.newFixedThreadPool(threads.length);

    public AppHost()
    {
        instance = this;
        //address = getHostIPAddress();
        threads[UI] = new Thread(new HostUI());
        threads[CONNECTION] = new Thread(new HostConnect());

        for (Thread t: threads) {
             executor.execute((Runnable) t);
             System.out.println("Running: "+t);
        }
    }
}

HostConnect：

public class HostConnect implements Runnable {
    public static HostConnect instance;
    private int port = 9000;
    InetAddress address; //Host Address. Server will be hosted here.
    ServerSocket server;
    Socket s;
    ObjectInputStream ois;
    ObjectOutputStream oos;

    public HostConnect()
    {   
        instance = this;
        try {
            server = new ServerSocket(port);
            System.out.println("Server Init Success.");
            address = getHostIPAddress();



        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

    public void run()
    {
        try{
            s = server.accept();
            ois = new ObjectInputStream(s.getInputStream());
            oos = new ObjectOutputStream(s.getOutputStream());

        }
        catch (Exception e)
        {
           e.printStackTrace(); 
        }

    }

    public InetAddress getHostIPAddress() 
    {
        try{
            InetAddress thisIP = InetAddress.getLocalHost();
            return thisIP;
        }
        catch(UnknownHostException e){
            return null;
        }

    }

    public InetAddress getAddress()
    {
        return address;

    }
}

HostUI：

public class HostUI extends javax.swing.JFrame implements Runnable {

    static HostUI instance;

    public HostUI() {
        initComponents();
        instance = this;
    }

    public void run() {
    new HostUI().setVisible(true);

    String addr = ""+HostConnect.instance.address;
    this.ipField.setText(addr);
    //System.out.println(ipField.getText());

}

Answer 1

与Swing组件（getter或setter）交互时，必须确保从Event Dispatch Thread调用方法。

如果没有，请使用invokeLater：

SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            ipField.setText(addr);
        }
});

Java JTextField在setText（）之后不更新文本

1 个答案: