如何在下载中获得每秒的字节数？

Question

我想知道如何在下载中获得每秒字节 这是我到目前为止所得到的：

while ((count = in.read(data, 0, byteSize)) > -1) {
    downloaded += count;
    fout.write(data, 0, count);
    output.setText(formatFileSize(downloaded) + "/ " + formatFileSize(fileLength));
     // perSecond.setText(formatFileSize((long) speed)+"/s");
    progressbar.setValue((int) downloaded);

    if (downloaded >= fileLength) {
        System.out.println("Done!");
        JOptionPane.showMessageDialog(frame, "Done!", "Info", 1);
        progressbar.setValue(0);
        output.setText("");
        perSecond.setText("");
        return;
    }    

我到底该怎么做？

Answer 1

一个选项是创建一个更新UI的DownloadProgressTask类。

示例：

class DownloadProgressTask extends TimerTask
{
    // I'm not sure what types these guys are so change them accordingly
    private Object output;
    private Object progressbar;

    private long fileLength = 0;

    private AtomicLong downloaded = new AtomicLong();

    public DownloadProgressTask (Object output, Object progressbar, long fileLength)
    {
        this.output = output;
        this.progressbar = progressbar;

        this.fileLength = fileLength;
    }

    // Do your task here
    public void run()
    {
        int downloadedInt = (int) downloaded.get();
        output.setText(formatFileSize(downloadedInt) + "/ " + formatFileSize(fileLength));
        // perSecond.setText(formatFileSize((long) speed)+"/s");
        progressbar.setValue(downloadedInt);
    }

    public void updateDownloaded (long newVal)
    {
        downloaded.set(newVal);
    }
}

然后，在开始读取文件的while循环之前，您将安排此任务：

示例：

// Create Timer Object
Timer time = new Timer(); 

// Create the download task
DownloadProgressTask dt = new DownloadProgressTask(output, progressbar, fileLength); 

// schedule task to run now and every 1 second thereafter
time.schedule(dt, 0, 1000);

现在，你的while循环看起来像是：

while ((count = in.read(data, 0, byteSize)) > -1) {
    downloaded += count;
    fout.write(data, 0, count);

    // let the task know the update
    dt.updateDownloaded(downloaded);

    if (downloaded >= fileLength) {

        // cancel the task here
        dt.cancel();

        System.out.println("Done!");
        JOptionPane.showMessageDialog(frame, "Done!", "Info", 1);
        progressbar.setValue(0);
        output.setText("");
        perSecond.setText("");
        return;
    }
}