使用WindowBuilder SWT時在Java中的多線程

Question

有人可以解釋爲什麼當我嘗試運行2個或更多線程時，此程序中的窗口凍結？

我希望能夠當兩個線程都運行在Hello按鈕點擊。 這是我的簡單項目。 任務類只打印出單詞「測試」。

public class Task extends Thread { 
public static boolean keepRun = true; 

public void run(){ 
    while(keepRun == true){ 
    System.out.println("Testing..."); 

    try { 
     Thread.sleep(1000); 
    }catch(InterruptedException e){}}; 
} 
} 

閉合類停止線程，當它在控制檯內鍵入停止。

import java.util.Scanner; 
public class Closing implements Runnable{ 
Scanner s = new Scanner(System.in); 
public void run() { 

    while (s.next().equals("stop")){ 
      System.out.println("Threads down"); 

      Task.keepRun =false; 

    try { 
     Thread.sleep(5000); 
    }catch(InterruptedException e){} 
    }; 

} 
} 

import org.eclipse.swt.widgets.Display; 
import org.eclipse.swt.widgets.Shell; 
import org.eclipse.swt.widgets.Button; 
import org.eclipse.swt.SWT; 
import org.eclipse.swt.events.SelectionAdapter; 
import org.eclipse.swt.events.SelectionEvent; 

這裏是主窗口類的位置。

public class Window { 

protected Shell shell; 

/** 
* Launch the application. 
* @param args 
*/ 
public static void main(String[] args) { 
    try { 
     Window window = new Window(); 
     window.open(); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
} 

/** 
* Open the window. 
*/ 
public void open() { 
    Display display = Display.getDefault(); 
    createContents(); 
    shell.open(); 
    shell.layout(); 
    while (!shell.isDisposed()) { 
     if (!display.readAndDispatch()) { 
      display.sleep(); 
     } 
    } 
} 

/** 
* Create contents of the window. 
*/ 
protected void createContents() { 
    shell = new Shell(); 
    shell.setSize(192, 208); 
    shell.setText("SWT Application"); 

    Button btnRun = new Button(shell, SWT.NONE); 
    btnRun.addSelectionListener(new SelectionAdapter() { 
     @Override 
     public void widgetSelected(SelectionEvent e) { 
      Task newTask = new Task(); 
      Closing closing = new Closing(); 
      newTask.start(); 
      closing.run(); 
     } 
    }); 
    btnRun.setBounds(50, 32, 75, 25); 
    btnRun.setText("Run"); 

    Button btnHello = new Button(shell, SWT.NONE); 
    btnHello.addSelectionListener(new SelectionAdapter() { 
     @Override 
     public void widgetSelected(SelectionEvent e) { 
      System.out.println("Hello"); 
     } 
    }); 
    btnHello.setBounds(50, 81, 75, 25); 
    btnHello.setText("Hello"); 

} 
} 

Answer 1

改寫這個：

Closing closing = new Closing(); 
newTask.start(); 
closing.run(); 

這樣：

Closing closing = new Closing(); 
newTask.start(); 
new Thread(closing).start(); 

看看這段代碼：

public class Closing implements Runnable{ 
    Scanner s = new Scanner(System.in); 
    public void run() { 

     while (s.next().equals("stop")){ 
      System.out.println("Threads down"); 

      Task.keepRun =false; 

      try { 
       Thread.sleep(5000); 
      }catch(InterruptedException e){} 
     }; 
    } 
} 

如果你打電話只是run();，Thread.sleep(5000);將受到線另一方面，當你創建一個新的線程時，sleep會影響到這個線程。