Question

• (Write/read data) Write a Program in BlueJ to create a file name Excersise12_15.txt if it does not exist. Write 100 integers created randomly into the file using text I/O. Integers are separated by spaces in the file. Read data back from the file and display the data in increasing order.
• After writing the file to disk, the input file should be read into an array, sorted using the static Arrays.sort() method from the Java API and then displayed in the terminal window with each of the numbers on a separate line
• Sorting of arrays: however for this option read the input file into an array of 100 elements and sort the array using either a selection or insertion sort before writing the list of numbers to the terminal window

Answer 1

Code:

import java.util.*;
import java.io.*;

public class Exercise_12_15 {
        /** Main method */
        public static void main(String[] args) throws Exception {
                File file = new File("Exercise12_15.txt");
                if (file.exists()) {
                        System.out.println("File already exists");
                        System.exit(0);
                }

                try (
=                       PrintWriter output = new PrintWriter(file);
                ) {
                        for (int i = 0; i < 100; i++) {
                                output.print(((int)(Math.random() * 500) + 1));
                                output.print(" ");
                        }
                }

                ArrayList<Integer> list = new ArrayList<>();

                try(
                        Scanner input = new Scanner(file);
                ) {
                        while (input.hasNext()) {
                                list.add(input.nextInt());
                        }
                }

                Collections.sort(list);

                System.out.print(list.toString());
                System.out.println();
        }
}

Let me know if you have any doubts or if you need anything to change. 

If you are satisfied with the solution, please leave a +ve feedback : ) Let me know for any help with any other questions.

Thank You!
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