Question

我在下面的代码中得到了MalformedURLexception，我不知道是什么导致它。

public void down(String url)
    {     try {
        URL url1 = new URL(url);


        HttpURLConnection urlConnection = (HttpURLConnection) url1.openConnection();
        urlConnection.setRequestMethod("GET");
        urlConnection.setDoOutput(true);
        urlConnection.connect();   
        File SDCardRoot = Environment.getExternalStorageDirectory();
        //create a new file, specifying the path, and the filename
        //which we want to save the file as.
        File file = new File(SDCardRoot,"somefile.ext");


        FileOutputStream fileOutput = new FileOutputStream(file);

        InputStream inputStream = urlConnection.getInputStream();

        int totalSize = urlConnection.getContentLength();
        int downloadedSize = 0;

        byte[] buffer = new byte[1024];
        int bufferLength = 0; //used to store a temporary size of the buffer

        while ( (bufferLength = inputStream.read(buffer)) > 0 ) {

                fileOutput.write(buffer, 0, bufferLength);
                //add up the size so we know how much is downloaded
                downloadedSize += bufferLength;
                //report progress


        }

        fileOutput.close();


    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();

    }
    }
}

它说未知的协议。阅读部分出现时连接完全正常，在此之前，代码甚至打印正确的文件大小。我试图下载的文件也有一个网址 http://download12.aomethin.com/blaa-blaa 如果我尝试添加www，请求将开始重定向。虽然我认为这可能是一个noobish但我也想知道如何获取该文件的名称并使用该名称保存文件而不是我选择的文件。

编辑：程序现在正在运行我只需要知道如何获得正确的文件名。并将其作为后台流程。

Answer 1

在主线程上下载不是一个好习惯;你应该在新的线程上实现它;因为在下载时，主线程正忙于下载文件。如果等待时间超过预期，系统将生成“无响应”错误。

为了做到这一点，您可以使用“TaskAsync”或“IntentService”，甚至可以创建新主题。但是，我建议[ TaskAsync ]，因为它很容易实现。

这是一个很好的做法，自己设置文件名：

public void downloadClicked() {
    InputStream in = null;
    FileOutputStream f = null;      
    try {
        String path ="ftp://administrator:password@131.164.140.118:21/MyShedule.zip";
        String targetFileName = "MyShedule.zip";

        URL u = new URL(path);
        URLConnection c =  u.openConnection();         

        c.setDoOutput(true);
        c.connect();
        String string = Environment.getExternalStorageDirectory().getPath().toString();

        in = c.getInputStream();

        f = new FileOutputStream(new File(string +"/kidsLibrary/"+ targetFileName));

        IOUtils.copy(in, f);

        } catch (MalformedURLException e) {
            Toast.makeText(KidsLibrary.this, e.toString(), Toast.LENGTH_LONG)
            .show();            
        } catch (ProtocolException e) {         
            Toast.makeText(KidsLibrary.this, e.toString(), Toast.LENGTH_LONG)
            .show();
        } catch (FileNotFoundException e) {        
            Toast.makeText(KidsLibrary.this, e.toString(), Toast.LENGTH_LONG)
            .show();
        } catch (IOException e) {           
            Toast.makeText(KidsLibrary.this, e.toString(), Toast.LENGTH_LONG)
            .show();
    } finally {
          IOUtils.closeQuietly(in);
          IOUtils.closeQuietly(f);
        }   
}

程序在android下载文件时冻结

1 个答案: