mkdir() works while inside internal flash storage, but not SD card?

Question

I am currently building a file management app that allows the user to browse the file system of their device. The user starts off in the root directory / of the

Answer 1

Try with this. It works fine for me.

final String NEW_FOLDER_NAME = "TestFolder";

String extStore = System.getenv("EXTERNAL_STORAGE");
File f_exts = new File(extStore, NEW_FOLDER_NAME);

String secStore = System.getenv("SECONDARY_STORAGE");
File f_secs = new File(secStore, NEW_FOLDER_NAME);

testPath(f_exts);

textPath(f_secs);

and change boolean value in testPath function as follows

boolean success;
if(path.exists()) {
    // already created
    success = true;
} else {
    success = path.mkdir();
}

If folder already exists, path.mkdir() method return false.

and done.!!!

reference from this question.