SwingWorkerProcessor.java Source code

Introduction

Here is the source code for SwingWorkerProcessor.java

Source

import java.awt.BorderLayout;
import java.awt.Container;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;

class SwingWorkerProcessor extends SwingWorker<Integer, Integer> {
    private final SwingWorkerFrame frame;
    private int iteration;
    private int intervalInMillis;

    public SwingWorkerProcessor(SwingWorkerFrame frame, int iteration, int intervalInMillis) {
        this.frame = frame;
        this.iteration = iteration;

        if (this.iteration <= 0) {
            this.iteration = 10;
        }
        this.intervalInMillis = intervalInMillis;
        if (this.intervalInMillis <= 0) {
            this.intervalInMillis = 1000;
        }
    }

    @Override
    protected Integer doInBackground() throws Exception {
        int sum = 0;
        for (int counter = 1; counter <= iteration; counter++) {
            sum = sum + counter;
            this.publish(counter);
            if (Thread.interrupted()) {
                throw new InterruptedException();
            }
            if (this.isCancelled()) {
                break;
            }
            Thread.sleep(intervalInMillis);
        }

        return sum;
    }

    @Override
    protected void process(List<Integer> data) {
        for (int counter : data) {
            frame.updateStatus(counter, iteration);
        }
    }

    @Override
    public void done() {
        try {
            frame.doneProcessing();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

class SwingWorkerFrame extends JFrame {
    String startMessage = "Please click the   start button...";
    JLabel statusLabel = new JLabel(startMessage);
    JButton startButton = new JButton("Start");
    JButton cancelButton = new JButton("Cancel");
    SwingWorkerProcessor processor;

    public SwingWorkerFrame() {
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        Container contentPane = this.getContentPane();
        cancelButton.setEnabled(false);

        contentPane.add(statusLabel, BorderLayout.NORTH);
        contentPane.add(startButton, BorderLayout.WEST);
        contentPane.add(cancelButton, BorderLayout.EAST);

        startButton.addActionListener(e -> startProcessing());
        cancelButton.addActionListener(e -> cancelProcessing());
    }

    public void setButtonStatus(boolean canStart) {
        if (canStart) {
            startButton.setEnabled(true);
            cancelButton.setEnabled(false);
        } else {
            startButton.setEnabled(false);
            cancelButton.setEnabled(true);
        }
    }

    public void startProcessing() {
        setButtonStatus(false);
        processor = new SwingWorkerProcessor(this, 10, 1000);
        processor.execute();
    }

    public void cancelProcessing() {
        processor.cancel(true);
        setButtonStatus(true);
    }

    public void updateStatus(int counter, int total) {
        String msg = "Processing " + counter + "  of  " + total;
        statusLabel.setText(msg);
    }

    public void doneProcessing() throws Exception {
        if (processor.isCancelled()) {
            statusLabel.setText("Process  cancelled ...");
        } else {
            int sum = processor.get();
            statusLabel.setText("Sum  is " + sum);
            setButtonStatus(true);
        }
    }
}

public class Main {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            SwingWorkerFrame frame = new SwingWorkerFrame();
            frame.pack();
            frame.setVisible(true);
        });
    }
}