Java Marks Sheet --Easy

Easy Just Copy This Code and save It Compile It and Run IT!!!

import java.io.*;
public class PRAC4
{
 public static void main (String []args)throws IOException
 {
 int roll_no;
 String full_name;
 String grade;
 String section;
 Double sdt;
 Double sfc;
 Double db;
 Double cs;
Double total;
 Double average;
 System.out.println("--------------");
 System.out.println("Inputs");
 System.out.println("--------------");
 System.out.println("Enter Roll No :");
 roll_no=readInteger();
 System.out.println("Enter Student Full Name");
 full_name=readString();
 System.out.println("Enter Student Grade :");
 grade=readString();
 System.out.println("Enter Student Section :");
 section=readString();
 System.out.println("OBTAINED MARKS :");
 System.out.println("--------------");
 System.out.println("Enter SDT :");
 sdt=readDouble();
 System.out.println("Enter SFC :");
 sfc=readDouble();
 System.out.println("Enter DB :");
 db=readDouble();
 System.out.println("Enter CS :");
 cs=readDouble();
 total=sdt+sfc+cs+db;
 average=total/4;
 System.out.println("Enter Full Name :"+full_name);
 System.out.println("--------------");
 System.out.println("Grade :"+grade);
 System.out.println("--------------");
 System.out.println("Section :"+section);
 System.out.println("--------------");
 System.out.println("SDT :"+sdt);
 System.out.println("--------------");
 System.out.println("SFC :"+sfc);
 System.out.println("--------------");
 System.out.println("DB :"+db);
 System.out.println("--------------");
 System.out.println("CS :"+cs);
 System.out.println("--------------");
 System.out.println("Sum :" +total);
 System.out.println("--------------");
 System.out.println("Percentage :"+average);
 System.out.println("--------------");
 }
 public static int readInteger()throws IOException
 {
 InputStreamReader isr=new InputStreamReader (System.in);//Bridge
 BufferedReader br=new BufferedReader (isr);//way
 String tmp=br.readLine(); return (Integer.parseInt(tmp));
 }
 public static Double readDouble()throws IOException
 {
 InputStreamReader isr=new InputStreamReader (System.in);//Bridge
 BufferedReader br=new BufferedReader (isr);//way
 String tmp=br.readLine(); return (Double.parseDouble(tmp));
 }
 public static String readString()throws IOException
 {
 InputStreamReader isr=new InputStreamReader (System.in);//Bridge
 BufferedReader br=new BufferedReader (isr);//way
 String tmp=br.readLine(); return ((tmp));
 }
 }