random - Java RandomGenerator no reponse to be repeated twice in a row -

i need output random number relate repose. pick 1 need generate random number no number repeated twice in row. know have store previous value not know start. here code.

private string pickdefaultresponse() {     // pick random number index in default response list.     // number between 0 (inclusive) , size of list (exclusive).     int previndex;     int newindex;     int index = randomgenerator.nextint(defaultresponses.size());      return defaultresponses.get(index);                  } 

previndex must not inside method, keep @ class level.

private int previndex = -1;  private string pickdefaultresponse() {     int index = 0;     {         index = randomgenerator.nextint(defaultresponses.size());     } while( index == previndex );     previndex = index;     return defaultresponses.get(index);                 }