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ProstoCoder
Asked:2020-03-29 08:45:35 +0800 CST2020-03-29 08:45:35 +0800 CST

下载进度文件

  • 772

再会。我需要一种从特定路径同时下载多个文件到特定目录的方法。基本上，我知道该怎么做。最简单的方法是通过 FileUtils，但我需要监控进度。有没有进步的选择，也许是一些图书馆？我发现了很多很棒的 android 库，但我没有找到任何适用于桌面的库。

java

1 个回答

  1. Best Answer
    public class DownloadProgress {
    public static void main(String[] args) {
        final JProgressBar progressBar = new JProgressBar();

        JFrame frame = new JFrame();
        frame.setContentPane(progressBar);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setSize(300, 70);
        frame.setVisible(true);

        new Thread(() -> {
            try {
                URL url = new URL("http://gornostaev.su/media/files/data.zip");
                HttpURLConnection httpConnection = (HttpURLConnection) (url.openConnection());

                long fileSize = httpConnection.getContentLength();
                long chunkSize = fileSize / 100;

                try (BufferedInputStream in = new BufferedInputStream(httpConnection.getInputStream());
                     BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("data.zip"), 1024)) {

                    byte[] data = new byte[1024];
                    long downloaded = 0;
                    int read = 0;
                    while ((read = in.read(data, 0, 1024)) != -1) {
                        out.write(data, 0, read);

                        downloaded += read;

                        final int progress = (int) (downloaded / chunkSize);
                        SwingUtilities.invokeLater(() -> {
                            progressBar.setValue(progress);
                        });
                    }
                }
            }
            catch (FileNotFoundException exc) {}
            catch (IOException exc) {}

            SwingUtilities.invokeLater(() -> {
                progressBar.setString("Done");
                progressBar.setStringPainted(true);
            });
        }).start();        
    }
}
    • 1

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