Writing dummy data to the selected file of external storage android

See more:

Mobile

Android

file

In the below mentioned code I am writing dummy data to all files present in external storage and renaming to "abc.txt". But what I want is to write dummy data to only that file which I select and rename that particular file. How do I do?

File[] files = root.listFiles();
for ( File f : files ) {
if (f.isDirectory())
continue;
FileChannel rwChannel = new RandomAccessFile(f, "rw").getChannel();
int numBytes = (int)rwChannel.size();
ByteBuffer buffer = rwChannel.map(FileChannel.MapMode.READ_WRITE, 0, numBytes);
System.out.println("buffer"+buffer);
byte[] randomBytes = new byte[numBytes];
new Random().nextBytes(randomBytes);
buffer.put(randomBytes);
rwChannel.write(buffer);
rwChannel.close();
}
File root1 = android.os.Environment.getExternalStorageDirectory();
File[] files1 = root.listFiles();
for ( File f : files ) {
if (f.isDirectory())
continue;
File myFile1 = new File(root,"abc.txt");
f.renameTo(myFile1);
}