Playing video from app cache dir

问题:

Can anyone explain why downloading/playing a video from my applications cache directory does not work, but downloading/playing the same video from my sdcard does work?

Note: this video is being downloaded. I am saving to memory before calling VideoView.setVideoPath(...).

// Works
File file = new File(Environment.getExternalStorageDirectory(), "vid-test.3gp");

// Does not work
File file = new File(getCacheDir(), "vid-test.3gp");

In each case the file in question does exist.

If I attempt to call VideoView.setVideoURI(...) and "stream" the video to my VideoView, it is hit and miss whether or not it will work.

Can anyone explain this behavior?

回答1:

It's probably a permission issue. Here is a working snipped:

InputStream in = connection.getInputStream();

File file = new File(getApplicationContext().getCacheDir() ,fileName);

if(!file.exists()){
    file.setReadable(true);

    file.createNewFile();


    if (file.canWrite()){

        FileOutputStream out = new FileOutputStream(file);   

        byte[] buffer = new byte[1024];
        int len1 = 0;
        while ( (len1 = in.read(buffer)) > 0 ) {
            out.write(buffer,0, len1);
        }

        out.close();
    }

    in.close();

    Runtime.getRuntime().exec("chmod 755 "+getCacheDir() +"/"+ fileName);                       

}