Exception 'open failed: EACCES (Permission denied)' on Android

Question

I am getting

open failed: EACCES (Permission denied)

on the line OutputStream myOutput = new FileOutputStream

Answer 1

In my case I was using a file picker library which returned the path to external storage but it started from /root/. And even with the WRITE_EXTERNAL_STORAGE permission granted at runtime I still got error EACCES (Permission denied).
So use Environment.getExternalStorageDirectory() to get the correct path to external storage.

Example:
Cannot write: /root/storage/emulated/0/newfile.txt
Can write: /storage/emulated/0/newfile.txt

boolean externalStorageWritable = isExternalStorageWritable();
File file = new File(filePath);
boolean canWrite = file.canWrite();
boolean isFile = file.isFile();
long usableSpace = file.getUsableSpace();

Log.d(TAG, "externalStorageWritable: " + externalStorageWritable);
Log.d(TAG, "filePath: " + filePath);
Log.d(TAG, "canWrite: " + canWrite);
Log.d(TAG, "isFile: " + isFile);
Log.d(TAG, "usableSpace: " + usableSpace);

/* Checks if external storage is available for read and write */
public boolean isExternalStorageWritable() {
    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state)) {
        return true;
    }
    return false;
}

Output 1:

externalStorageWritable: true
filePath: /root/storage/emulated/0/newfile.txt
isFile: false
usableSpace: 0

Output 2:

externalStorageWritable: true
filePath: /storage/emulated/0/newfile.txt
isFile: true
usableSpace: 1331007488