JAVA：JProgressbar & Files.copy 1 中有 Observer 和 Swingworker Class

Question

几个月前我写了一篇文章

但我想对 I 进行一些更改。现在我所有的代码都在 Swingworker class 中完成。但是我想使用 MVC 方法并使用观察者模式来更新视图中的变量。

现在我有这样的东西

    public class CopyFrame extends JFrame {

        private JTextarea textArea;
        private JProgresbar progresbar;

        public CopyFrame(){
            progresbar = new JProgresbar
            textArea = new JTextarea();
            progresbar.setMaximum(100));
            /*in this method I added the components correctly*/ 
            addComponentsCorrecty();

            new Task().execute();
        }


        class Task extends Swingworker<Void,Void>{
            /*Dp this 10 times*/
            Files.Copy(source, destination);
            progresbar.setValue(progresbar.getValue + 10);

            String info = String.format("%s is completed", source)

        textArea.setText(textArea.getText + "\n" + info)
        }
    }

我想创建这样的东西

public class CopyFrame extends JFrame {

    private JTextarea textArea;
    private JProgresbar progresbar;

    public CopyFrame(){
        progresbar = new JProgresbar
        textArea = new JTextarea();
        progresbar.setMaximum(100));
        /*in this method I added the components correctly*/ 
        addComponentsCorrecty();

        Task task = new Task();
        task.addObserver(this);
        task.execute
    }

    @Override
    public void update(){
        progresbar.setValue(progresbar.getValue +10);
        textArea.setText(textArea.getText + "\n" + task.getInfo)
    }   
}
class Task extends Swingworker<Void,Void> extends Observer{

        private String info;
        public Task(){
            doTask;
        }

        public void doTask(){
        /*Dp this 10 times*/
        Files.Copy(source, destination);
        info = String.format("%s is completed", source)
        setChanged();
        notifyObservers();
        }

        public String getInfo(){
            return info;
        }
}

我该怎么做？因为我不能从 2 classes 扩展。我想从另一个 class (TASK)

更新进度条

我最好的选择是什么

Answer 1

SwingWorker 以 PropertyChangeListener 的形式提供了一种观察者模式。

这会提供有关状态变化 (running/done/etc) 和进度变化的通知。

例如：

JProgressBar isn't progressing
How to use jProgress bar for ProcessBuilder process?
how to include a progress bar in a program of file transfer using sockets in java
Java - global, reusable loading dialog
JProgressBar won't update

有点厌倦了重写 PropertyChangeListener，我确实创建了一个简单的适配器，它提供了更直接的事件通知

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.SwingWorker;

public class SwingWorkerListener<W extends SwingWorker> implements PropertyChangeListener {

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        W worker = (W) evt.getSource();
        switch (evt.getPropertyName()) {
            case "state":
                workerStateChanged(worker);
                switch (worker.getState()) {
                    case STARTED:
                        workerStarted(worker);
                        break;
                    case DONE:
                        workerDone(worker);
                        break;
                }
                break;
            case "progress":
                workerProgressUpdated(worker);
                break;
        }
    }

    protected void workerProgressUpdated(W worker) {
    }

    protected void workerStateChanged(W worker) {
    }

    protected void workerStarted(W worker) {
    }

    protected void workerDone(W worker) {
    }

}

这允许我覆盖我真正感兴趣的方法并减少我必须继续编写的 repeated/boiler 板代码的数量

请记住，Swing 基础 "listeners" 实际上是观察者模式的一种形式 ;)

JAVA：JProgressbar & Files.copy 1 中有 Observer 和 Swingworker Class

JAVA: JProgressbar & Files.copy With Observer and Swingworker in 1 Class

java

copy

observer-pattern

extends

swingworker