Largest Digit in a Single Integer Value 
The following program returns largest Digit in a Single Integer 
Ex: Input 7896 
Output: 9
public class LargestDigit {
	public static void main(String[] args) {

		System.out.println(new LargestDigit().getLargestDigit(7896));
	}

	public int getLargestDigit(int number) {
		int max;
		if (number / 100 == 0) {
			if (number % 10 > (number / 10) % 10) {
				max = number % 10;
			} else
				max = (number / 10) % 10;
		} else if (number % 10 > number % 100)
			max = number % 10;
		else
			max = number % 100;

		return max / 10;
	}
}

Result:
Ouput: 9