连接JProgressBar与下载过程

问题描述

限时删除！！

我有以下代码。我不能让它工作。

我不得不提到网址正在重定向。我的意思是 url = http://www.thissite.com 并重定向到 http://www.othersite.com 。但是我想要使用初始的 url 。

  public void download（String address，String localFileName，JProgressBar progress）{
 OutputStream out = null; 
 URLConnection conn = null; 
 InputStream in = null; 
 
 try {
 
 URL url = new URL（address）; 
 
 
 
 //打开本地文件系统上目标文件的输出流
 out = new BufferedOutputStream（new FileOutputStream（/ MusicDownloads /+ localFileName） ）; 
 conn = url.openConnection（）; 
 
 in = conn.getInputStream（）; 
 
 int length = conn.getContentLength（）; //找出文件多久，任何好的网络服务器应该提供这个信息
 int current = 0; 
 progress.setMaximum（length）; //我们要得到这么多字节
 progress.setValue（0）; //我们已经得到0个字节到目前为止
 
 //获取数据
 byte [] buffer = new byte [1024]; 
 int numRead = 0; 
 
 while（（numRead = in.read（buffer））！= -1）{
 current = 0; 
 out.write（buffer，current，numRead）; 
 
 current + = numRead; //我们已经进步了一点，所以更新当前
 
 progress.setValue（current）; //告诉进度我们有多远
 
 
} 
 //完成！只需要清理
} catch（异常异常）{
 exception.printStackTrace（）; 
} finally {
 try {
 if（in！= null）{
 in.close（）; 
} 
 if（out！= null）{
 out.close（）; 
} 
} catch（IOException ioe）{
 //不应该发生，如果你不是
 //愚弄，可能会添加一些日志记录;）
 
} 
} 
  

解决方案

使用。

I have the below code. I can't make it work.

I have to mention that the URL is redirecting. I mean that url = http://www.thissite.com and redirects to http://www.othersite.com. But I want to get it work with the initial url.

 public void download(String address, String localFileName, JProgressBar progress ) {
    OutputStream out = null;
    URLConnection conn = null;
    InputStream in = null;

    try {

          URL url = new URL(address);



        // Open an output stream to the destination file on our local filesystem
        out = new BufferedOutputStream(new FileOutputStream("/MusicDownloads/"+localFileName));
        conn = url.openConnection();

        in = conn.getInputStream();

        int length = conn.getContentLength(); //find out how long the file is, any good webserver should provide this info
         int current = 0;
          progress.setMaximum(length); //we're going to get this many bytes
          progress.setValue(0); //we've gotten 0 bytes so far

        // Get the data
        byte[] buffer = new byte[1024];
        int numRead = 0;

        while ((numRead = in.read(buffer)) != -1) {
            current=0;
            out.write(buffer, current, numRead);

              current += numRead; //we've progressed a little so update current

            progress.setValue(current); //tell progress how far we are


        }
        // Done! Just clean up and get out
    } catch (Exception exception) {
        exception.printStackTrace();
    } finally {
        try {
            if (in != null) {
                in.close();
            }
            if (out != null) {
                out.close();
            }
        } catch (IOException ioe) {
            // Shouldn't happen, maybe add some logging here if you are not
            // fooling around ;)
        }
    }
}

解决方案

Use a ProgressMonitorInputStream instead.

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