Display Some Messages On Output File In Display Head Function

Write a class named FileDisplay with the following methods:

1.) constructor: the class's constructor should take the name of a fil as an arugment.
2.) displayHead: This method should display only the first five lines of the file's contents

Here is the following code I have made so far

import java.io.*;
public class FileDisplay
{
private String filename;
 public FileDisplay(String Filename) throws IOException

[Code] ....

First, in my constructor I have taken in an argument and used that argument to open up an output file. Meanwhile, I'm trying to work n the displayhead method to print out information and to read data to. I haven't opened up my input file yet, but I'm not understand how can I read a print data to an output file. in

public void displayHead()
{FileWriter file=new FileWriter(Filename)}

do I make create another instance of the filewriter class to output data?

In simple words, suppose to I want to display some messages on my output file in the displayhead function. Since I already have opened up the file in the constructor, how do I combine that in this method...