Question

java question: Write a program that reads in data from a text file named in.txt. Compute the sum of all the valid integers in the input file. Likewise, compute the sum of all the valid doubles in the input file. Write the former to an output file called int_total.txt, and write the latter to an output file called double_total.txt. B) Write a program that converts the Java source code from the next-line brace style to the end-of-line brace style. For example, the following Java source in (a) uses the next-line brace style. Your program converts it to the end-of-line brace style in (b).

(a) Next-line brace style public class Test { public static void main(String[] args) { // Some statements } }

(b) End-of-line brace style public class Test { public static void main(String[] args) { // Some statements } }

Java class files must be named after the class. (For example, for a class called Test, the file must be called Test.java.) Thus the original code will be in a file called ClassName.java (fill in ClassName with whatever test class you use). Preserve the original code style by writing it to a file called ClassName_newlinebraces.java. Write the end-of-line brace style to ClassName.java.

Answer 1

A.

// Java program to calculate the sum of all valid ints and doubles from a file and output the result to 2 output files
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;

public class FileSum {

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

       double dblTotal = 0;
       int intTotal = 0;
       File file = new File("in.txt"); // provide full path to file
       // check if file exists
       if(file.exists())
       {
           Scanner fileScan = new Scanner(file); // open the input file
           // read till the end of file
           while(fileScan.hasNext()) {
              
               if(fileScan.hasNextInt()) // if next element read is an integer
                   intTotal += fileScan.nextInt(); // read and add the integer to intTotal
               else if(fileScan.hasNextDouble()) // if next element read is a double
                   dblTotal += fileScan.nextDouble(); // read and add the double to dblTotal
               else // if neither integer nor double, read and discard the next element as string
                   fileScan.next();
           }
           fileScan.close(); // close the input file
           // create and open 2 output files
           PrintWriter intWriter = new PrintWriter("int_total.txt");
           PrintWriter dblWriter = new PrintWriter("double_total.txt");
          
           // output the sum of all valid integers
           intWriter.write("Sum of all valid integers in file in.txt : "+intTotal);
           // output the sum of all valid doubles
           dblWriter.write("Sum of all valid doubles in file in.txt: "+dblTotal);
          
           // close the output files
           intWriter.close();
           dblWriter.close();
       }else
           System.out.println("Unable to open file in.txt");

   }

}

//end of program

Output:

Input file:

Output File: