Simplest example of using SharedPreferences in Android to store key-pair values.

SharedPreferencesExample.java

String message = "Hi";
static String fileName = "shared_string";
SharedPreferences sharedPreferences;
sharedPreferences = getSharedPreferences(fileName, MODE_PRIVATE);

//Inserting
SharedPreferences.Editor = sharedPreferences.edit();
editor.putString("message", message);
editor.commit();

//Retrieving
String defaultValue = "Nothing found";
String message = sharedPreferences.getString("message", defaultValue);