my_7_Boom

package Main;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;

public class Tester {
    public static void main(String[] args) throws FileNotFoundException {

        make7Boom("BoomTxt",1000);

    }
    public static void make7Boom(String fileName,int maxNumber) throws FileNotFoundException {

        File f=new File(fileName);
        PrintWriter pw=new PrintWriter(f);

        for(int count=1;count<maxNumber;count++){
            if(count%7==0 || has7(count))
                pw.println("Boom");
            else
                pw.println(count);
        }
        pw.close();
    }

    public static Boolean has7(int number){

        while(number>0){
            if (number%10==7)
                return true;
            number/=10;
        }
        return false;
    }
}