Write multiple lines in a text file ( java)

Question

This following code is to run a command in cmd and to produce a text file with the output from the command line. The code below shows the correct information in the output window in Eclipse, but only one last line is printed in the text file. Can anyone help me with this?

import java.io.*;

public class TextFile {
public static void main(String[] args) throws IOException {
    try {
        Process p = Runtime.getRuntime().exec("git log");

        BufferedReader in = new BufferedReader(
                new InputStreamReader(p.getInputStream()));
        BufferedWriter writer = null;

        String line = null;
        while ((line = in.readLine()) != null) {

            writer = new BufferedWriter(new FileWriter("textfile.txt"));
            writer.write(line);
            System.out.println(line);

            writer.close();
        }

    } catch (IOException e) {
        e.printStackTrace();

    }

   }
}

Answer 1

As stated in other answer, problem is that you are creating BufferedWriter instance inside while loop and that is why only last line is getting printed in file.

One of the better way to write this program using try-with-resources -

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;

public class TextFile {

    public static void main(String[] args) throws IOException {
        try {
            Process p = Runtime.getRuntime().exec("git log");

            try (BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
                    BufferedWriter writer = new BufferedWriter(new FileWriter("textfile.txt"))) {

                String line = null;
                while ((line = in.readLine()) != null) {
                    writer.write(line);
                    writer.newLine();
                    System.out.println(line);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();

        }
    }
}