Question

Write a complete Java program, including comments in both the main program and in each method, which will do the following:

0. The main program starts by calling a method named introduction which prints out a description of what the program will do. This method is called just once.

     This method is not sent any parameters, and it does not return a value. The method should print your name. Then it prints several lines of output explaining what the program does (it should also say how to end the set of data—see step 4).

1. Then the main program asks the user to type in an integer value which the main program calls n; n could be positive, negative, or zero (see step 4). The main program prints the number n after it is read in. Use a negative value to end.

2. The main program calls a method named isiteven, sending it the integer value n as a parameter. The method determines whether or not n is even, sending the answer back to main. (Hint: if n is even, the remainder when n is divided by 2 is 0; this works for all even numbers, including 0.) You may return an integer (like 0 or 1) to represent even or odd, or return a character (like ‘e’ or ‘o’), or a boolean.

The main program prints the answer returned together with a message. For example, if you send 6, the method determines it is even, and the main program prints that 6 is an even number.

3a. If n is even, the main program calls a method named sumEvenSquares, sending n to the method as a parameter. The method computes the sum of the first n even squares (see below). The method returns this sum to the main program. Then the main program prints a message giving n and the sum of the first n even squares.

For example, if you send 4, then the sum of the first 4 even squares is 2*2 + 4*4 + 6*6 + 8*8 = 4+16+36+64 = 120.

Note the method computes the sum of the first n even squares- this will be: 2*2 + 4*4 + 6*6 + ... + (2n)*(2n), where n is the parameter value sent to the method. DO NOT use any other formula for calculating this value; use the sum of series.

b. However, if n is odd, the main program calls a method named sumOddNumbers, sending it n. The method computes the sum of the first n odd numbers (NOT n odd squares - see below). The method returns this sum to the main program. Then the main program prints a message giving n and the sum of the first n odd numbers.

For example, if you send 3, then the sum of the first 3 odd numbers is 1 + 3 + 5 = 9. For n=5, it is 1+3+5+7+9 = 25, etc. (Although this value will be equal to n squared, calculate it as a series; don’t just find n squared.)

Note the method computes the sum of the first n odd numbers- this will be: 1 + 3 + 5 + ... + (2n-1), where n is the parameter value sent to the method.

In either case, the main program calls one of two methods to compute a sum of terms, then prints the method's answer.

4. After calling a method to compute the appropriate sum and printing the result, the main program will skip a few lines and go back to step 1 (not step 0).   At step 1, if the user types in a negative value, the program will go to step 5.

5. At the end, print how many data values were entered and processed. (Make sure that this number is at least 8.)

DATA: Type in a total of at least 8 data values. Have at least four even numbers (make sure 0 is one of the even numbers) and four odd numbers; intersperse the values: odd, then 2 evens, then odd, etc. Have one value of each type that is between 10 and 20 (and the rest smaller).

     You will be judged on the quality of your data.

STYLE: Be sure that each method has a good comment explaining two things: exactly what parameter(s) the method will receive, and exactly what the method will do (and if it returns an answer or prints). Mention parameters by name in the comment.

OUTPUT: Send output to an external file. You will need to pass it as a parameter.

Here is some sample output (ignoring the introduction):

the original integer is 5

5 is an odd number

the sum of the first 5 odd numbers is 25

the original integer is 4

4 is an even number

the sum of the first 4 even numbers is 120

OPTIONAL: If the user enters a negative value, say this is no good, ask the user to type in a new value that is good (greater than or equal to 0). The program continues until the user enters a special value (not just any negative value) that signals the end.

Answer 1

The output filename is passed as an command line argument

..the program could be run from terminal as java Javaprogram.java file_name.txt....  

Or for netbeans IDE go to Run tab and then project configuration and then wirte the filename in agrument field in dialog box opened and then run the program

The java code snipped and screen shots has been attached below

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package javaprogram;

import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

/**
 *
 * @author vijay
 */
public class Javaprogram {

    /**
     * @param args the command line arguments
     */
   static BufferedWriter out; //object for writing to the file
    //this function has no parameter and has void return type..it simply prints the introduction of program
    public static void introduction() throws IOException //this function prints the introduction as given in question
    {
        out.write("Name : vijay \n The program is to take a input of integer "
                + "\nIf the input is -1(special integer) then program will terminate else \n If the "
                + "input is positive then  if it is even then it is displayed at the main that it is even "
                + "and then sum of even squares upto that even number is calculated \n...If"
                + "the number is odd then then again it is notifed and sum of first n odd numbers is calculated  "
                + " if the number is negative then it is asked to enter the another good value\n\n "   );
        
        
    }
    //this function accept  an integer parameter and returns whether the passed paramenter is even or odd
    public static char isiteven(int n)//this function  check whether the number is even or dd
    {
        if(n%2==0) //if remainder is 0 it is even
            return 'e'; //return 'e' which means even
        else
            return 'o';//return 'o' which means od 
        
    }
    //this function accepts an integer parameter n and returns the integer which is sum of first n even squares 
    public static int sumEvenSquares(int n) //this function calculates the sum of first n even squares
    {
        int sum=0;   //intialising the sum to 0
        for(int i=2;i<=2*n;i+=2) //traversing the loop from 2 to 2*n ..at an update of 2
        { 
            sum+=i*i;  //adding i*i to sum variable
        }
    return sum; //returning the calculated sum
    }
    
    //this function accepts an integer parameter n and returns the integer which is sum of first n odd numbers
    public static int sumOddNumbers(int n)
    {
        int sum=0;   //intialising the sum to 0
        for(int i=1;i<=2*n-1;i+=2)//traversing the loop from 1 to 2*n-1 ..at an update of 2
        {
            sum+=i; //adding i to sum variable
        }
        return sum; //returning the calculated sum
    }
    
    
    
    public static void main(String[] args) throws IOException {
        // TODO code application logic here
          String Filename=args[0];//taking file name as command line arguement
        FileWriter fout=new FileWriter(Filename); //creating FileWriter object to write on the file
        out=new BufferedWriter(fout); //intialising BufferedWriter object by passing object of FileWriter
          Scanner sc =new Scanner(System.in); //creating object of scanner class to take the inputs
        introduction(); //prints the introduction of the program
        int count=0 ; //count the number of inputs processed
        while(true)  //making a while loop to return the below statements for couple of times
        {
            System.out.println("Enter any integer...(-1 to terminate the program) \n");
            int n=sc.nextInt();//taking the input from stdin
            if(n==-1) //checking condition for termination
            {
                break; //break the loop if n=-1
            }
            count ++;
            out.write("The orignal integer is "+n+"\n");
            char typeOfInteger=isiteven(n);//calls isiteven method to check whether number is even or odd
        if(typeOfInteger=='e') //checking if number is even 
        {
            out.write(n + " is an even number \n");//printing the number is even
            int sum=sumEvenSquares(n);//calling sumEvenSquares function to calculate the sum of first n even squares
           out.write("The sum of first "+n +" even squares is "+sum+"\n");//printing the required sum
           
            
        }
        else
        {
            out.write(n + " is an odd number\n");//printing the number is odd
            int sum=sumOddNumbers(n);//calling sumOddNumbers function to calculate the sum of first n odd numbers
           out.write("The sum of first "+n +" odd numbers is "+sum+"\n");//printing the required sum
           
            
        }
            
            
            
            
        }
         out.write("The total data values eneterd and processed are :"+ count);//wirte the total input processed to the file
        out.close();//closing the stream
        
        
    
    }
    
}

Screenshot