如何将文件指针重置为Java中的文件开头？

public class FiFo {
    public static void main(String[] args) 
    {
        FileReader file1=new FileReader("d:testfilesFILE1.txt");
        FileReader file2=new FileReader("d:testfilesFILE2.txt");
        try{
            String s1,s2;
            while((s1=file1.data.readLine())!=null){
                System.out.println("s1: "+s1);
                while((s2=file2.data.readLine())!=null){
                    System.out.println("s2: "+s2);
                }
            }
            file1.closeFile();
            file2.closeFile();
        }catch (IOException e) {
            e.printStackTrace();
        }
    }
}

class FileReader {
    BufferedReader data;
    DataInputStream in;

    public FileReader(String fileName)
    {
        try{
            FileInputStream fstream = new FileInputStream(fileName);
            data = new BufferedReader(new InputStreamReader(fstream));
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    } 

    public void closeFile()
    {
        try{
            in.close();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}