Android I/O- write file to storage

androidFileHandling.java

// find the root of the external storage
File root = android.os.Environment.getExternalStorageDirectory();
myRootFolder.append("\nExternal file system root: " + root);
//make a new directory
File dir = new File (root.getAbsolutePath() + "/testDownload");
dir.mkdirs();
File file = new File(dir, "testData.txt");

try {
FileOutputStream f = new FileOutputStream(file);
PrintWriter pw = new PrintWriter(f);
pw.println("Hello World");
pw.flush();
pw.close();
f.close(); //An error occurs if you do not implement a catch for this expression
} catch (Exception e) {
e.printStackTrace();
Log.i(LOG_TAG, "File not found. Probably a permissions issue");
}

myRootFolder.append("\n\nFile written to" + file);