Q:

java txt file is over writing when use file and formatter

So i have tried every thing but the files keeps over writing the first line, i am passing these methods to another class so the three arguments in method add_records are passed through a scanner. 
here is the creating/opening method : 
    public class Io_Files{

    private Formatter output;

public void open_file_normal(String filename) throws IOException
{
    {
        try
        {
            FileWriter fileWriter = new FileWriter(filename, true);
            output = new Formatter(filename);
        }
        catch(FileNotFoundException fileNotFoundException)
        {
            System.err.println("Error");
        }
    }
}

and here is the code for adding record method: 
    public void add_records(String a, String b, int c) throws       FileNotFoundException{

output.format ("[%s, %s, %d]%n", a, b, c);

} 

please if you are able to help provide some comments on why and where to put the code so i can learn too.
cheers

A:

Try using
output = new Formatter(fileWriter);

instead of 
output = new Formatter(filename);

