JTidy java API toConvert HTML to XHTML

I am using JTidy to convert from HTML to XHTML but I found in my XHTML file this tag  . Can i prevent it ?
this is my code

    //from html to xhtml
   try   
    {  
        fis = new FileInputStream(htmlFileName);  
    }  
    catch (java.io.FileNotFoundException e)   
    {  
        System.out.println("File not found: " + htmlFileName);  
    }  
        Tidy tidy = new Tidy(); 
        tidy.setShowWarnings(false);
        tidy.setXmlTags(false);
        tidy.setInputEncoding("UTF-8");
        tidy.setOutputEncoding("UTF-8");
        tidy.setXHTML(true);// 
        tidy.setMakeClean(true);
        Document xmlDoc = tidy.parseDOM(fis, null);  
    try  
    {  
        tidy.pprint(xmlDoc,new FileOutputStream("c.xhtml"));  
    }  
    catch(Exception e)  
    {  
    }

i created a function that parse the the xhtml code and remove the unwelcome tags and to add a link to the css File "tableStyle.css"

    public static  String xhtmlparser(){ 
    String Cleanline="";

    try { 
        // the file url
        FileInputStream fstream = new FileInputStream("c.xhtml");
        // Use DataInputStream to read binary NOT text.
        BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
        String strLine = null;
        int linescounter=0;
        while ((strLine = br.readLine()) != null)   {// read every line in the file             
            String m=strLine.replaceAll(" ", "");
            linescounter++;
            if(linescounter==5)
                m=m+"\n"+ "<link rel="+ "\"stylesheet\" "+"type="+ "\"text/css\" "+"href= " +"\"tableStyle.css\""+ "/>";
            Cleanline+=m+"\n";
        }

    }
    catch(IOException e){}

    return Cleanline;
}

but as a performance issue is it good?

by the way it works will