Java中的SwingWorker

Question

我有个问题。我有一个JFrame。它将创建一个JDialog。当按下开按钮时JDialog，应将其丢弃并发送电子邮件。同时，我需要另一个JDialog以不确定的形式出现JProgressBar。发送电子邮件时，JDialog应将其丢弃（并重新创建一封信），或更改其内容。我现在已经失败了几个小时，所以我问enyone，他（或她）是否足够友善地为我编写一个可以满足我要求的伪代码。只是为了看看应该在SwingWorker类中包含什么（或者，如果您认为更好的话，可以使用多线程），JDialog应该在何时创建/处置（s）以及在哪里保留发送电子邮件...我知道我要在这里寻求完整的解决方案，但是我处于底线，已经失败了很多次……这是我的最后选择……

Answer 1

我做了一个简短的例子，希望对您有所帮助。基本上显示一个JFramewitha按钮：

JButton单击框架上的时，JDialog将出现一个JButton（另一个）（发送电子邮件）-这表示电子邮件对话框：

当JButton上emailDialog按下其配置的emailDialog，并创建一个新的JDialog将举行的进度（或在这种情况下，一个简单的JLabel）：

然后它创建并执行SwingWorker发送电子邮件和dispose()的JDialog当其完成并显示JOptionPane出发送的成功消息：

import java.awt.BorderLayout;

import java.awt.Dimension;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.*;

public class Test {

    public static void main(String[] args) throws Exception {

        SwingUtilities.invokeLater(new Runnable() {

            @Override

            public void run() {

                new Test().createAndShowUI();

            }

        });

    }

    private void createAndShowUI() {

        JFrame frame = new JFrame();

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        initComponents(frame);

        frame.setPreferredSize(new Dimension(300, 300));//testing purposes

        frame.pack();

        frame.setVisible(true);

    }

    private void initComponents(final JFrame frame) {

        final JDialog emailDialog = new JDialog(frame);

        emailDialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);

        emailDialog.setLayout(new BorderLayout());

        JButton sendMailBtn = new JButton("Send Email");

        sendMailBtn.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                //get content needed for email from old dialog

                //get rid of old dialog

                emailDialog.dispose();

                //create new dialog

                final JDialog emailProgressDialog = new JDialog(frame);

                emailProgressDialog.add(new JLabel("Mail in progress"));

                emailProgressDialog.pack();

                emailProgressDialog.setVisible(true);

                new Worker(emailProgressDialog).execute();

            }

        });

        emailDialog.add(sendMailBtn, BorderLayout.SOUTH);

        emailDialog.pack();

        JButton openDialog = new JButton("Open emailDialog");

        openDialog.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                emailDialog.setVisible(true);

            }

        });

        frame.getContentPane().add(openDialog);

    }

}

class Worker extends SwingWorker<String, Object> {

    private final JDialog dialog;

    Worker(JDialog dialog) {

        this.dialog = dialog;

    }

    @Override

    protected String doInBackground() throws Exception {

        Thread.sleep(2000);//simulate email sending

        return "DONE";

    }

    @Override

    protected void done() {

        super.done();

        dialog.dispose();

        JOptionPane.showMessageDialog(dialog.getOwner(), "Message sent", "Success", JOptionPane.INFORMATION_MESSAGE);

    }

}

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Answer 2

L＆F物质的输出（因为您对EDT的不确定性有待测试）

run:

JButton openDialog >>> Is there EDT ??? == true

Worker started >>> Is there EDT ??? == false

waiting 30seconds 

Worker endeded >>> Is there EDT ??? == false

before JOptionPane >>> Is there EDT ??? == false

org.pushingpixels.substance.api.UiThreadingViolationException: 

     Component creation must be done on Event Dispatch Thread

和另外200行有关详细信息

输出是 "correct container created out of EDT"

我将在另一家L＆F上进行测试，Nimbus可能存在问题，SystemLokkAndFeel在大多数情况下并不关心EDT上的重大错误（对EDT的敏感性完全不同），默认情况下，Metal在Windows平台上没有任何问题，对于Java6，那么您的示例也可以在第二基础上使用

从代码

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Font;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.*;

import javax.swing.plaf.FontUIResource;

public class Test {

    public static void main(String[] args) throws Exception {

        try {

            for (UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {

                if ("Nimbus".equals(info.getName())) {

                    UIManager.setLookAndFeel(info.getClassName());

                    UIManager.getLookAndFeelDefaults().put("nimbusOrange", (new Color(127, 255, 191)));

                    break;

                }

            }

        } catch (ClassNotFoundException ex) {

        } catch (InstantiationException ex) {

        } catch (IllegalAccessException ex) {

        } catch (javax.swing.UnsupportedLookAndFeelException ex) {

        }

        SwingUtilities.invokeLater(new Runnable() {

            @Override

            public void run() {

                /*try {

                    UIManager.setLookAndFeel(

                            "org.pushingpixels.substance.api.skin.SubstanceOfficeBlue2007LookAndFeel");

                    UIManager.getDefaults().put("Button.font", new FontUIResource(new Font("SansSerif", Font.BOLD, 24)));

                    UIManager.put("ComboBox.foreground", Color.green);

                } catch (Exception e) {

                }*/

                new Test().createAndShowUI();

            }

        });

    }

    private void createAndShowUI() {

        JFrame frame = new JFrame();

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        initComponents(frame);

        frame.setPreferredSize(new Dimension(300, 300));//testing purposes

        frame.pack();

        frame.setVisible(true);

    }

    private void initComponents(final JFrame frame) {

        final JDialog emailDialog = new JDialog(frame);

        emailDialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);

        emailDialog.setLayout(new BorderLayout());

        JButton sendMailBtn = new JButton("Send Email");

        sendMailBtn.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                //get content needed for email from old dialog

                //get rid of old dialog

                emailDialog.dispose();

                //create new dialog

                final JDialog emailProgressDialog = new JDialog(frame);

                emailProgressDialog.add(new JLabel("Mail in progress"));

                emailProgressDialog.pack();

                emailProgressDialog.setVisible(true);

                new Worker(emailProgressDialog, frame).execute();

            }

        });

        emailDialog.add(sendMailBtn, BorderLayout.SOUTH);

        emailDialog.pack();

        JButton openDialog = new JButton("Open emailDialog");

        openDialog.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                System.out.println("JButton openDialog >>> Is there EDT ??? == " + SwingUtilities.isEventDispatchThread());

                emailDialog.setVisible(true);

            }

        });

        frame.getContentPane().add(openDialog);

    }

}

class Worker extends SwingWorker<String, Object> {

    private final JDialog dialog;

    private final JFrame frame;

    Worker(JDialog dialog, JFrame frame) {

        this.dialog = dialog;

        this.frame = frame;

    }

    @Override

    protected String doInBackground() throws Exception {

        System.out.println("Worker started >>> Is there EDT ??? == " + SwingUtilities.isEventDispatchThread());

        System.out.println("waiting 30seconds ");

        Thread.sleep(30000);//simulate email sending

        System.out.println("Worker endeded >>> Is there EDT ??? == " + SwingUtilities.isEventDispatchThread());

        dialog.dispose();

        System.out.println("before JOptionPane >>> Is there EDT ??? == " + SwingUtilities.isEventDispatchThread());

        JOptionPane.showMessageDialog(frame, "Message sent", "Success", JOptionPane.INFORMATION_MESSAGE);

        System.out.println("before JOptionPane >>> Is there EDT ??? == " + SwingUtilities.isEventDispatchThread());

        return null;

    }

}

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Answer 3

只需done()在SwingWorker中重写该方法，然后将调用移至JOptionPane.showMessageDialog(frame, "Message sent", "Success", JOptionPane.INFORMATION_MESSAGE);该方法中。该方法done()一旦doInBackground()完成将被调用，并在EDT上运行。