Java FileWriter skip files

April 13, 2022

I have a package with files : "100.txt" ,"1000.txt", "10000.txt","100000.txt", "1000000.txt".
But when i launch my program, it skips 100 and 1000 txt files. Can you tell me why?

public void generateData(Path path) throws IOException {
        for (int i = 1; i <= 5; i++){
            for (int j = 100; j <= 1000000; j*=10){
                FileWriter fileWriter = new FileWriter(path.resolve(Integer.toString(i)).resolve(j + ".txt").toFile());
                Random random = new Random();
                for (int k = 0; k < j; k++){
                    int num = random.nextInt(10);
                    fileWriter.write(num);
                    fileWriter.write("\n");
                }
            }
        }
    }

>Solution :

I ran your code and everything seemed to run pretty well.

All files were printed:

100.txt
1000.txt
10000.txt
100000.txt
1000000.txt

One thing I noticed is that you don’t close your FileWriter after you’re done with it. Perhaps that is the problem.

Here is the full code I ran. I did remove the writing of the files into the numbered directories since those directories didn’t exist on my machine.

package forloop;

import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Random;

public class GenerateData {

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

        Path path = Paths.get("");

        generateData(path);
    }

    public static void generateData(Path path) throws IOException {
        for (int i = 1; i <= 5; i++){
            for (int j = 100; j <= 1000000; j*=10){
                FileWriter fileWriter = new FileWriter(path.resolve(j + ".txt").toFile());
                Random random = new Random();
                for (int k = 0; k < j; k++){
                    int num = random.nextInt(10);
                    fileWriter.write(num);
                    fileWriter.write("\n");
                }
                fileWriter.close();
            }
        }
    }
}