how to fix: boolean array for random lottery number program. "can't convert int to boolean"

I need to make a random lottery generator for class with a boolean array. at first i made it with an int array and it worked perfectly fine but when i changed the int array to a bool array i got an error that says "Type mismatch: cannot convert from int to boolean". I'm wondering how to fix my code so this will work.

    int highestNumber, numsInLottery, randomNum;
    //int[] lottery = new int[numsInLottery];

    System.out.println("Welcome to the Lottery Number Generator!");
    System.out.println("How many numbers are in your lottery?");
    numsInLottery = TextIO.getInt();
    System.out.println("What is the highest number in your lottery?");
    highestNumber = TextIO.getInt();

    boolean[] lottery = new boolean[numsInLottery];

    for(int i = 0; i < numsInLottery; i++)
    {
        randomNum = (int)(Math.random() * highestNumber);
        for(int x = 0; x < i; x++ )
        {

            /*if (lottery[x] == randomNum)
            {
            randomNum = (int)(Math.random() * highestNumber);
            x = -1;
            }*/
        }   
        lottery[i] = randomNum;
        System.out.print(lottery[i] + " ");
    }

        //System.out.print(lottery[i] + " ");
    }
}