Question

1.      Create 100 text files automatically; in each file write a random number from 1 to 10. Use outputstreams (fileoutputstream, buffredwriter….)

2.      Read the content of the 100 files and combine them into a 1 single file.

3.      Write java code to do the following:

a.      To write the following text into a text file EEEESAAA@23SDCFSAWERF%WASDFGHWERTRQW

b.      Read the file using a java program

c.      Find how many D’s in the file

d.      Extract the text between the @ and the #

1. Create 100 text files automatically; in each file write a random number from 1 to 10. Use outputstreams (fileoutputstream, buffredwriter….)

2. Read the content of the 100 files and combine them into a 1 single file.

3. Write java code to do the following:

a. To write the following text into a text file EEEESAAA@23SDCFSAWERF%WASDFGHWERTRQW

b. Read the file using a java program

c. Find how many D’s in the file

d. Extract the text between the @ and the #

all of this in a single program

Answer 1

Find the code for the above question below, read the comments provided in the code for better understanding. If found helpful please do upvote this.
Please refer to the screenshot of the code to understand the indentation of the code.

Copyable code

import java.util.Random;

import java.io.*;

public class fileread {

    public static void main(String args[]) {

        int count = 100;// numbe rof files to create

        // Part 1

        // run a loop for 100 times so as to create 100 files

        for (int i = 1; i <= count; i++) {

            // get random integer between 1 to 10

            Random rand = new Random();

            int randomVal = rand.nextInt(10) + 1;

            // craete file name file1.txt , file2.txt and so on

            try (BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("file" + i + ".txt"))) {

                // write the random variable value into the file

                bufferedWriter.write("" + randomVal);

            } catch (IOException e) {

                // show error if any

                System.out.println("Error : " + e.getMessage());

            }

        }

        System.out.println(count + " files created");

        // Part 2

        // run a loop for 100 times so as to read the 100 files

        String combinedData = "";

        for (int i = 1; i <= count; i++) {

            // rwad the files

            try (BufferedReader bufferedReader = new BufferedReader(new FileReader("file" + i + ".txt"))) {

                combinedData += bufferedReader.readLine() + "\n";

            } catch (IOException e) {

                // show error if any

                System.out.println("Error : " + e.getMessage());

            }

        }

        // now write teh combineddata into the file100.txt

        try (BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("file" + count + ".txt"))) {

            // write the cobined data into the file

            bufferedWriter.write(combinedData);

        } catch (IOException e) {

            // show error if any

            System.out.println("Error : " + e.getMessage());

        }

        System.out.println("Combined data of all files written in file" + count + ".txt");

        // /Question 3

        try (BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("file_ques3.txt"))) {

            // write the value into the file

            bufferedWriter.write("EEEESAAA@23SDCFSAWERF%WASDFGHWERTRQW");

        } catch (IOException e) {

            // show error if any

            System.out.println("Error : " + e.getMessage());

        }

        // read the file content

        try (BufferedReader bufferedReader = new BufferedReader(new FileReader("file_ques3.txt"))) {

            String fileData = bufferedReader.readLine();

            // count number of D's in it

            int dCount = 0;

            for (int i = 0; i < fileData.length(); i++)

                if (fileData.charAt(i) == 'D')

                    dCount++;

            System.out.println("Number of D's int the file : " + dCount);

            // Extract the text between the @ and the #

            String extractedText = fileData.substring(fileData.indexOf('@')+1, fileData.indexOf('%'));

            System.out.println("Extracted Text : " + extractedText);

        } catch (IOException e) {

            // show error if any

            System.out.println("Error : " + e.getMessage());

        }

    }

}

Screenshot of code

Output

Files Created