string - writing in text file in java -

i have text file contained large number of words, , want divide words writing ** every 4 words. did until adding first ** ( first 4 words) , have difficulties in putting other stars.

here code until (i using java)

import java.io.*;  public class insert {   public static void main(string args[]){      try {        insert in = new insert();        int tc=4;         in.insertstringinfile (new file("d:/users//im080828/desktop/souad/project/reduction/weight/outdata/d.txt"), tc, "**");        }      catch (exception e) {        e.printstacktrace();        }  }    public void insertstringinfile(file infile, int lineno, string linetobeinserted)     throws exception {  // temp file  file outfile = new file("$$$$$$$$.tmp");   // input  fileinputstream fis  = new fileinputstream(infile);  bufferedreader in = new bufferedreader      (new inputstreamreader(fis));   // output           fileoutputstream fos = new fileoutputstream(outfile);  printwriter out = new printwriter(fos);   string thisline = "";  int =1;  while ((thisline = in.readline()) != null) {    if(i == lineno) out.println(linetobeinserted);    out.println(thisline);    i++;    } out.flush(); out.close(); in.close();  infile.delete(); outfile.renameto(infile);  } } 

please.. give me ideas

thanks :)

when if (i == lineno) true if (i==4), behavior normal. need use modulo operator if ((i % lineno) == 0) star every lines. http://www.dreamincode.net/forums/topic/273783-the-use-of-the-modulo-operator/