How do I append data to a text file?

One of the common task related to a text file is to append or add some contents to the file. It really simple to do this in Java using a FileWriter class. This class has a constructor that accept a boolean parameter call append. By setting this value to true a new data will be appended at the end of the file when we write a new data to it. Let’s see an example.

package org.kodejava.example.io;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class AppendFileExample {
    public static void main(String[] args) {
        File file = new File("user.txt");

        try {
            FileWriter writer = new FileWriter(file, true);
            writer.write("username=kodejava;password=secret"
                    + System.getProperty("line.separator"));
            writer.flush();
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}