生成几个不相同的数字

Random r = new Random();
  int temp[] ={0,0,0,0,0,0,0,0,0,0};
  String fourNum="";
  while(fourNum.length()!=9){
      int t = r.nextInt(9);
      if(temp[t]==0){
      fourNum+=t;
      temp[t]=1;
   }
  }
System.out.println(fourNum);