CODEWITHSUNDEEP
javaswinginheritancejframe
Kevik
Kevik

Reputation: 9361

how to extend JFrame in a class that already extends Thread

I have a class that extends Thread, and need to extend JFrame on the same class. since multiple inheritance is not possible in Java, how do it use JFrame objects inside of a class that already extends Thread?

Upvotes: 2

Views: 7145

Answers (3)

Cyrille Ka
Cyrille Ka

Reputation: 15533

Instead of extending either JFrame or Thread, use composition, it is a lot less limiting:

public class MyApplication {
    JFrame applicationFrame;

    Thread someThread;

    MyApplication() {
        SwingUtilities.invokeLater(new Runnable() {
            @Override void run() {
                applicationFrame = new JFrame();

                // some more GUI initialization.
                applicationFrame.setVisible(true);
            }
        });

        someThread = new Thread(new Runnable() {
            @Override void run() {
                // do my work.
            }
        });

        someThread.start();
    }

    public static void main(String... args) {

        new MyApplication();
    }
}

Upvotes: 13

Hovercraft Full Of Eels
Hovercraft Full Of Eels

Reputation: 285430

You can use JFrames and Threads easily without extending them, and as has been suggested by most, you are usually better off not extending them. Extending them binds your class to the JFrame preventing you from later using it in a JPanel, JDialog, etc. Why restrict yourself like this if not necessary?

Upvotes: 2

Bracket
Bracket

Reputation: 432

Rather than extending Thread, can you make the class implement Runnable? This way, you could extend JFrame instead, pass it to a Thread.

public class MyFrameThread extends JFrame implements Runnable {

    @Override
    public void run() {
        ...
    }
}

public static void main(String... args) {
    Thread myThread = new Thread(new MyFrameThread());
    myThread.start();
    myThread.join();
}

Upvotes: 3

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