Question

以下是start.mp4文件的SD卡路径。我能够以读取模式获取此文件，但无法在rw模式下打开。我也给了运行时权限。它引发了一个例外：

/storage/3263-6232/piyush/Download/start.mp4：open failed：EACCES（Permission denied）

这是代码：

//This is the sd-card path of the file which needs to be edited

String sdCardPath = "/storage/3263-6232/piyush/Download/start.mp4"; 
File file = new File(sdCardPath );
try{

RandomAccessFile rfs = new RandomAccessFile(file, "rw");

rfs.seek(file.length());
rfs.close();

} catch (IOException e) {
   e.printStackTrace();
}
In the above code I have taken sdcardpath to a file which exists in sdcard. Than after that whenever I tried to open that file in outputstream using RandomAccessFile it gives FilenotFound Exception:

/storage/3263-6232/piyush/Download/start.mp4: open failed: EACCES (Permission denied)

Answer 1

如果您使用的是Android 6及更高版本，则应该提出运行时权限请求那样：

    private void requestPermission() {

    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1);

    }

和你的onCreate：

public void onCreate(){
requestPermission();
}

仅在文件位于SD卡中的情况下才能在Fileoutputstream中打开文件

1 个答案: