In the Code below i have a program using multi dimensional arrays. I have a quick question on "How to" ad a checking system so my random class does not generate the same "type" of horse twice. For instance right now i have my program pick a random color with the name stallion i do not want it to pick blue twice

Main Class

String[][] horses = {{"Black ","White ","Gray ","Old ","Young ",
                             "Pink ","Yellow ","Brown ","Orange ","Cyan ", 
                             "Purple ","Tan ","Cerulean ","Silver ","Gold ", 
                             "Red ","Green ","Blue ","Maroon ","Marigold ", 
                             "Iron ","Paper ","Wood ","Zinc ","Metal "},
                             {"Stallion"}
                           };
                         
      String[][] horsePlace = {{pickRand.get(horses[0]), pickRand.get(horses[0]),  pickRand.get(horses[0])
                              , pickRand.get(horses[0]), pickRand.get(horses[0]), pickRand.get(horses[0])},
                              {pickRand.get(horses[1]), pickRand.get(horses[1]), pickRand.get(horses[1]),
                               pickRand.get(horses[1]), pickRand.get(horses[1])}};

Random Class

import java.util.Random;
class pickRand {
    public static String get (String[] array) {
        Random generator = new Random();
        int rnd = generator.nextInt(array.length);
        return array[rnd];
    }
}

keep an array, or a list with types you've already added.
when you create a new one, check in that array or list whether it already exists, if not, add it to the list, if it does, ignore it and create a new one.

for future reference, when you say: this is my main method, you may want to show the complete code you have in the main method, that might be easier for us.