java.io.IOException: open failed: EACCES (Permission denied)异常解决

1、首先检查Manifest.xml中是否添加这三个权限

<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

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

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

2、此时如果仍然不能解决问题的话，那么看一下你的系统版本是否到了6.0。

如果高于或等于6.0的话，那么就要在代码中加权限了，

存储权限

private static final int REQUEST_EXTERNAL_STORAGE = 1;
private static String[] PERMISSIONS_STORAGE = {
        Manifest.permission.READ_EXTERNAL_STORAGE,
        Manifest.permission.WRITE_EXTERNAL_STORAGE
};


/**
 *

检查应用程序是否允许写入存储设备

 *
 *

如果应用程序不允许那么会提示用户授予权限

 *
 * @param activity
 */
public static void verifyStoragePermissions(Activity activity) {
    // Check if we have write permission
    int permission = ActivityCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);


    if (permission != PackageManager.PERMISSION_GRANTED) {
        // We don't have permission so prompt the user
        ActivityCompat.requestPermissions(
                activity,
                PERMISSIONS_STORAGE,
                REQUEST_EXTERNAL_STORAGE
        );
    }
}