Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)-优快云博客

在Android API级别23及以上，除了在AndroidManifest.xml中声明权限，还需要在运行时通过JAVA代码请求权限。错误'Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)'表明缺少必要的运行时权限，解决方法是在相关方法前调用权限请求。

在API23+以上，不止要在AndroidManifest.xml里面添加权限

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     }