Question

Please Explain the following question in detail so that I can understand how to solve it:

Assume that you want to use both an input file called "myinput.txt" and an output file called "myoutput.txt" which are located in a folder called "mydata" on the g: drive.

In the program below, fill in all the missing details so that you can read a series of values (one by one) from the input file into the variable "num". Continue to read values and process them until you have processed the value 64(not 64 items, but an item whose value is 64). At the end you may print the total number of values read from the file to the output file. To do this you may have to declare additional variables, include statements to control reading from and writing to files, ect...

Program:
import java.util.Scanner;
import java.io.*;
public class Problem2 {
   public static void main(String[] args) throws IOException
   {
       int num;

       do{
       //read a value into num - you must show how you accomplish this.

       }while
      

   }
}

Answer 1

/**
* The java program that opens a input file called myinput.txt file and read the
* values from file . Then check if the value read from the file is not 64, then
* write the value to the myoutput.txt file. The process of reading and writing
* continues until the number read from file not 64. The program also counts
* the number of values read from file . Print the number of values read from file
* to console output.
*
* */
//Problem2.java
import java.util.Scanner;
import java.io.*;
public class Problem2 {
   public static void main(String[] args) throws IOException
   {
       int num;
      
       //Set input and output file paths
       //Note : D is drive name, If G drive available, then replace D with G letter
       String inputFileName="D:\\myinput.txt";
       String outputFileName="D:\\myoutput.txt";

       Scanner fileReader=null;
       PrintWriter writer=null;
       int count=0;

       final int SENTINAL=64;
       try
       {
           //Open Scanner object to read input file
           fileReader=new Scanner(new File(inputFileName));
           //Create an instance of PrintWriter object to write to output file
           writer=new PrintWriter(new File(outputFileName));
          
           //read values until num is not 64
           do
           {
               //read data from file
               num=fileReader.nextInt();
               //check if num is not 64 then increment the count by 1
               //write the value of num to output file
               if(num!=SENTINAL)
               {
                   count++;
                   writer.printf("%3d",num);
               }

           }while(num!=SENTINAL);
           //Print the count on console output
           System.out.println("Total numbers read from file :"+count);

       }
       catch(FileNotFoundException exp)
       {
           System.out.println(exp.getMessage());
       }
       finally
       {
           //close input and output objecs
           fileReader.close();
           writer.close();
       }                   
   }//end of main method
}//end of class

Sample Input file :

myinput.txt

25 35 45 55 75 85 64

Output of the program:

Total numbers read from file :6

myoutput.txt

25 35 45 55 75 85