Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)

今天遇到一个项目中用到Android 6.0的系统，但是有个文件是从Assert目录下写到SDCard中，但是AndroidMinifest.xml中已经加了文件的读权限和写权限，异常日志是在创建文件的时候报错了。

在API23+以上

1 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
2 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

还要在Java代码中请求权限：

 1     // Storage Permissions
 2     private static final int REQUEST_EXTERNAL_STORAGE = 1;
 3     private static String[] PERMISSIONS_STORAGE = {
 4             Manifest.permission.READ_EXTERNAL_STORAGE,
 5             Manifest.permission.WRITE_EXTERNAL_STORAGE };
 6
 7     /**
 8      * Checks if the app has permission to write to device storage
 9      *
10      * If the app does not has permission then the user will be prompted to
11      * grant permissions
12      *
13      * @param activity
14      */
15     public static void verifyStoragePermissions(Activity activity) {
16         // Check if we have write permission
17         int permission = ActivityCompat.checkSelfPermission(activity,
18                 Manifest.permission.WRITE_EXTERNAL_STORAGE);
19
20         if (permission != PackageManager.PERMISSION_GRANTED) {
21             // We don't have permission so prompt the user
22             ActivityCompat.requestPermissions(activity, PERMISSIONS_STORAGE,
23                     REQUEST_EXTERNAL_STORAGE);
24         }
25     }