This example give you an example using java.text.DecimalFormat class to add leading zeros to a number. For a another method you can read the see the earlier example on How do I add leading zeros to a number?.

package org.kodejava.example.lang;

import java.text.DecimalFormat;
import java.text.NumberFormat;

public class NumberFormatLeadingZerosExample {
    public static void main(String[] args) {
	NumberFormat formatter = new DecimalFormat("0000000");
	String number = formatter.format(2500);
	
	System.out.println("Number with lading zeros: " + number);
    }
}