How To Select Random Values From A Given Range

I'm trying to create an android application which will generate random series of values (integer numbers in this case) in a given range (but NOT equal between them) and display the

Solution 1:

Random r = new Random(<a seed number>);

Set<Integer> mySet = new HashSet<Integer>();
while (mySet.size() < 5) {
   int idx = r.nextInt(<length of your data>)
   mySet.add(data[idx]);
}

data contains your range numbers.

String text = "";
for (Integer i : mySet) {
   text = text + i + ", "; 
}

set this text in your TextView.

Solution 2:

in the edit code:

int idx = r.nextInt();

needs to change to:

int idx = r.nextInt(data.length);

because you want to choose a random index from your data.

Solution 3:

If I understand this correctly, you all the numbers should be unique. You could fill a list with the range you want to draw from. Every time you have selected a value from it, you should remove it from the list so it won't be selected a second time. I hope this description is clear enough. If not, I will provide some code.

Solution 4:

int low = ...;
int high = ...;
List<Integer> choices = new LinkedList<Integer>();
for (int i = low; i <= high; i++) {
    choices.add(i);
} 

Collections.shuffle(choices);

int[] choices = newint[] {
  choices.get(0),
  choices.get(1),
  choices.get(2),
  choices.get(3),
  choices.get(4)
};

Solution 5:

finalStringBuilderbuilder=newStringBuilder();
finalRandomr=newRandom(System.currentTimeMillis());
final Set<Integer> numbers = newHashSet<Integer>();

public String getRandomNumbers(int count,int min, int max)
{
    if(count > (max - min) || (max < min))
        thrownewIllegalArgumentException("There is an error with the parameters provided");

    builder.setLength(0); //Clear StringBuilder
    numbers.clear(); //Clear the number listint i=0;
    while( i < count )
    {
        intaRandomNumber= (r.nextInt() % max) +min;

        if(numbers.contains(aRandomNumber)) // If we have seen this number alreadycontinue;
        else
        {
            i++;
            numbers.add(aRandomNumber);
            builder.append(aRandomNumber); //Add number to stringif( i < (count-1) )
                builder.append(", "); // Add a comma if it's not the last number
        }
    }

    Stringoutput= builder.toString();
    builder.setLength(0); //A polite clearing
    numbers.clear();

    return output;
}