Java线程连接问题

Question

public void setGifImage(InputStream inputStream) {
        checkWidget();
        if (thread != null) {
            thread.stopRunning();
            try {
                thread.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        ImageLoader loader = new ImageLoader();

        try {
            loader.load(inputStream);
        } catch (Exception e) {
            this.image = null;
            return;
        }

        if (loader.data[0] != null){
            System.out.println("set to new picture");
            this.image = new Image(this.getDisplay(), loader.data[0]);
        }

        if (loader.data.length > 1) {
            System.out.println("start animation");
            thread = new GifThread(loader);
            thread.start();
        }else{
            System.out.println("paint static picture");
        }

        redraw();
    }

线程 :

private class GifThread extends Thread {

        private int imageNumber = 0;
        private ImageLoader loader = null;
        private boolean run = true;

        public GifThread(ImageLoader loader) {
            this.loader = loader;
        }

        public void run() {
            while (run) {
                int delayTime = loader.data[imageNumber].delayTime;
                try {
                    Thread.sleep(delayTime * 10);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                if (!GifCLabel.this.isDisposed()) {
                    // if a asynchronous thread is running, this new runnable will be queued
                    GifCLabel.this.getDisplay().asyncExec(new Runnable() {
                        public void run() {
                            if (!GifCLabel.this.isDisposed()) {
                                imageNumber = imageNumber == loader.data.length - 1 ? 0 : imageNumber + 1;
                                if (!GifCLabel.this.image.isDisposed())
                                    GifCLabel.this.image.dispose();
                                ImageData nextFrameData = loader.data[imageNumber];
                                System.out.println("set to frame " + imageNumber);
                                GifCLabel.this.image = new Image(GifCLabel.this.getDisplay(), nextFrameData);
                                GifCLabel.this.redraw();
                            } else
                                stopRunning();
                        }
                    });
                } else
                    stopRunning();
            }
        }

        public void stopRunning() {
            run = false;
        }
    }

输出 :

2011-08-10 03:44:24 DEBUG  - 日志服务Ready!
2011-08-10 03:44:28 DEBUG  - current is null
2011-08-10 03:44:28 DEBUG  - found : amarsoft.dbmp.function.ui.FunctionListPage@1079ff
2011-08-10 03:44:28 DEBUG  - can go back ? false
2011-08-10 03:44:28 DEBUG  - can go forward ? false
set to new picture
start animation
2011-08-10 03:44:28 DEBUG  - 尝试连接至 - jdbc:mysql://localhost:3306/credit 驱动配置：MySQL 驱动类：com.mysql.jdbc.Driver@1f7abae 连接属性：{user=root, password=root}
set to frame 1
set to frame 2
set to frame 3
set to frame 4
[amarsoft.dbmp.function.ui.FunctionListPage$1@29f93b, amarsoft.dbmp.function.ui.FunctionView$1@1a998c7]
set to new picture
paint static picture
set to frame 5

我想知道为什么线程在 thread.join() 之后仍然运行？据我所知， thread.join() 等待线程死亡，但你可以看到输出中的最后一行，线程在死亡后运行......

Answer 1

这里的问题是，您线程调用 getDisplay().asyncExec() ，它基本上将事件发送到 UI 线程以执行打印 “设置为框架” 的 Runnable。

最好使用 syncExec() 并检查 Runnable 内的 run 变量状态。

另一个提示：

1. 捕获 InterruptedException 而不执行任何操作并不是一个好主意。
2. stopRunnable() 内调用 interrupt，
3. 在 sleep 结束后检查 run 变量状态。

干杯，
最大限度