JFrame opens over and over again

Question

I'm having troubles with this program. Everything works, but the program keeps opening the JFrame over and over again (and obviously, I only want just one JFrame to be opened). What is wrong with my code?

Thank you in advance, Stefan

 import java.util.*;
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;

public class ColoredWords {
  JFrame frame;
  JPanel controlPanel, wordsPanel;
  JButton match, nomatch;

  ColoredWords() {

    SwingUtilities.invokeLater( new Runnable() {
      @Override
      public void run() {
        frame = new JFrame("Colored Words Experiment");
        wordsPanel = new JPanel();
        controlPanel = new JPanel();
        frame.setLayout(new BorderLayout());
        frame.add(wordsPanel, BorderLayout.NORTH);
        frame.add(controlPanel, BorderLayout.SOUTH);
        frame.setSize(1000, 600);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
        match = new JButton("Matching");
        nomatch = new JButton("Non-Matching");
        controlPanel.add(match, BorderLayout.WEST);
        controlPanel.add(nomatch, BorderLayout.CENTER);
        ClicksReporter clicksreporter;
        clicksreporter =  new ClicksReporter();
        match.addActionListener(clicksreporter);
        nomatch.addActionListener(clicksreporter);
      }
    } );
  }


  class ClicksReporter extends ColoredWords implements ActionListener {
    Labeling labeling = new Labeling();
    public void actionPerformed(ActionEvent e) { 
      if (e.getActionCommand().equals("Matching")) {
        wordsPanel.add(labeling);
      } else if (e.getActionCommand().equals("Non-Matching")) {
        wordsPanel.add(labeling);
      }
    }
  }


  public static void main(String[] arg) {
    new ColoredWords();
  }
}

class Labeling extends JPanel {
  JLabel[] labelsList = new JLabel[20];
  int i = 0;

  public Labeling() {
    while (i < 5) {  
      labelsList[i] =  new JLabel("black");
      setLayout(new FlowLayout(FlowLayout.CENTER, 10, 10));
      labelsList[i].setOpaque(true);
      labelsList[i].setBackground(Color.white);
      add(labelsList[i]);
      i++;
    }
  }
}

I recommend you to read [The use of multiple JFrames, Good/Bad Practice?](http://stackoverflow.com/questions/9554636/the-use-of-multiple-jframes-good-bad-practice). Instead use a [Card Layout](http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html#card). — Frakcool, Oct 20 '14 at 17:08

score 1 · Accepted Answer · answered Oct 20 '14 at 15:45

The problem is when you instantiate ClicksReporter inside main(). This is because it inherits the constructor of ColoredWords, calling it when instantiated. To avoid this, you can take the program code out of the constructor and into another method, say, execute() or run(). You can then adjust your program accordingly to call this method in main().

score 0 · Answer 2 · answered Oct 20 '14 at 15:48

Your ColoredWords constructor calls clicksreporter = new ClicksReporter(); but ClicksReporter inherits ColoredWords, so the constructor of ColoredWords gets called, wich will again execute clicksreporter = new ClicksReporter(); and so on... You get stuck in an infinite loop. Try to remove inheritance.

score 0 · Answer 3 · answered Oct 20 '14 at 15:48

You create a new JFrame in your ColoredWords constructor.
You create a new ClicksReporter in your ColoredWords constructor.
ClicksReporter extends ColoredWords.

That means every ColoredWords construction leads to another ColoredWords construction, which also creates a JFrame.

JFrame opens over and over again

3 Answers3