Saving Data on Android

Utility.kt
.
The code for the 
READ
 and 
DELETE
 button click events are similar to what you 
added for the 
WRITE
 button; these already exist in the sample project.
It’s time for the next step!
Saving Data on Android
Chapter 1: Using Files
raywenderlich.com
23

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Open 
InternalFileRepository.kt
 and locate 
addNote
. Then, add the following to the 
body of the method:
context.openFileOutput(note.fileName, Context.MODE_PRIVATE).use 
{ output -> 
  output.write(note.noteText.toByteArray()) 
}
This code opens the file in 
fileOutputStream
 using the 
Context.MODE_PRIVATE
 
flag; using this flag makes this file private to this app. The 
FileOutputStream
 is a 
Closeable
 resource so we can manage it using the 
use
 Kotlin function. The note’s 
text is converted to a 
ByteArray
 and written to the file.
Run the program. Enter 
Test.txt
 for the file name and some text for the note. When 
you’re ready, tap the 
WRITE
 button. If the write is successful, the 
EditText
 controls 
will clear. Otherwise, the stacktrace is printed to Logcat.
Now that you’ve learned how to read, write and delete files on the internal storage, 
wouldn’t it be nice to see a visual representation of the files in the file system?