Check if key exists in Shared Preferences

Try contains(String key) Accorting to the Javadocs,

Checks whether the preferences contains a preference. Returns true if the preference exists in the preferences, otherwise false.

Every method for fetching values from SharedPreferences has default value which is returned in case the key does not exist

preferences = getSharedPreferences("text", 0);
String value = preferences.getString("unknown_key",null);
if (value == null) {
    // the key does not exist
} else {
    // handle the value
}

Try out

 SharedPreferences shf = getSharedPreferences("NAME_SharedPref", MODE_WORLD_READABLE);
    String strPref = shf.getString("SERVERIP", null);

    if(strPref != null) {
    // do some thing

    }