Java – allows users to enter only positive integers (no decimals or strings)?

I know how to ask users to enter positive integers, but I don't know how to handle code to avoid input errors, such as decimal or string input

int seedValue;
  double angle,gunpowder;

  System.out.println("Please enter a positive integer seed value: ");
  seedValue = input.nextInt();

     while (seedValue <= 0) {  
        System.out.println("Please enter a positive integer seed value: ");
        seedValue = input.nextInt();
     }

     System.out.println("That target is " +
      threeDec.format(gen.nextDouble() * 1000) + "m away.");

Solution

This may be an approval:

>Using scanner Readline() reads the input as a string value; > Try using integer The parseInt method converts the string to int. if the input string contains decimals and invalid numbers, this method will throw numberformatexception. > If the input value was parsed correctly in the previous step, check whether it is negative