Question

This is a code snippet but basically what I want to do is read from a file named ‘listings.txt’ and write to a file named ‘overview.txt’. I want to take the information out of ‘listings.txt’ and put them into ‘overview.txt’ as is (I will figure out the rest later).

The file ‘overview.txt’ is created and appears to loop through the file ‘listings.txt’ and write to ‘overview.txt’. However, once I open the file ‘overview.txt’ it is empty.
Could someone go through a quick glance at my code and spot something erroneous?

package yesOverview;

import java.io.BufferedReader;
import java.io.*;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;


public class yesOverview {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        String strInput = "foo.bar";
        System.out.print("Please enter the listings file (the full path to the file): ");
        strInput = input.next();

        //This makes sure that the inputed file is listings.txt as required for KET1 task 2
        while (strInput.contains("listings.txt") == false) {
            System.out.print("Incorrect file. Please enter listings file(the full path to the file): ");
            strInput = input.next();
        }

        infos(strInput);
        input.close();
    }

    public static void infos(String strInput) {
        Scanner input2 = new Scanner(System.in);
        System.out.print("Please enter the overview.txt file (the full path to the file): ");
        String strInput2 = "foo.bar";
        strInput2 = input2.next();

        //This also makes sure that the overview.txt file is provided. 
        while (strInput2.contains("overview.txt") == false) {
            System.out.print("Incorrect file. Please enter overview file(the full path to the file): ");
            strInput2 = input2.next();
        }

        //Creates the file f then places it in the specified directory.
        File f = new File(strInput2);

        try {
            //Creates a printerwriter out that writes to the output file. 
            PrintWriter out = new PrintWriter(strInput2);
        } catch (FileNotFoundException ex) {
            Logger.getLogger(KETTask2Overview.class.getName()).log(Level.SEVERE, null, ex);
        }

        //String that holds the value of the next line. 
        String inputLine = "";

        //Creates the Buffered file reader / writer.  
        try {
            BufferedReader in = new BufferedReader(new FileReader(strInput));
            FileWriter fstream = new FileWriter(strInput2);
            BufferedWriter out = new BufferedWriter(fstream);
            while (in.readLine() != null) {
                out.write(in.read());
            }
            in.close();
        } catch (IOException e) {
            System.err.println("Error: " + e.getMessage());
        }

    }
}

Answer 1

Try this

Close the BufferedWriter stream (ie out.close() )

try and use nextLine() instead of next(), as next() only takes in a single word, but for a complete line use nextLine(), though this doesnt seem to be the problem here.

What i do when i have to read and write to files, i normally follow these steps

For Reading from a file

File f = new File("my.txt");
FileReader fr = new FileReader(f);
BufferedReader br  = new BufferedReader(fr);

String s = null;

while ((br.readLine())!=null) {

// Do whatever u want to do with the content of the file,eg print it on console using SysOut...etc

}

br.close();

For Writing to a file:

Boolean isDone = true;
Scanner scan = new Scanner(System.in);
File f = new File("my.txt");
FileWriter fr = new FileWriter(f);
BufferedWriter br  = new BufferedWriter(fr);

while (isDone) {

   if (!isDone) {

 br.write(new Scanner(System.in).nextLine());

 }


}