How do I append data to a text file?

Date: 2010-09-16. Category: Java I/O examples. Hits: 24K time(s).

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.*;

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();
        }
    }
}