Is there a way to get a get linebreaks back after appending text file into a StringBuffer?

Question

In order to remove lines from a text file, I do the following:

 public void removeTagLine(String tag, String filename)
{
    try
    {
        BufferedReader br=new BufferedReader(new FileReader(filename));

        //String buffer to store contents of the file
        StringBuffer sb=new StringBuffer("");

        String line;

        while((line=br.readLine())!=null)
        {
            //Store each valid line in the string buffer
            if(!line.contains(tag))
                sb.append(line+"\n"); //here
        }
        br.close();

        FileWriter fw=new FileWriter(new File(filename));
        //Write entire string buffer into the file
        fw.write(sb.toString());
        fw.close();
    }
    catch (Exception e)
    {
        System.out.println("Something went horribly wrong: "+e.getMessage());
    }
}

This works exactly as I'd hope, except I lose all my newLines. It's worth noting that my newlines were done by doing

writer.newLine();

As you can see where I marked the comment //here , am adding a \n, yet the new file with the removed lines is still all in one line. What gives?

Answer 1

Use System.getProperty("line.separator"); instead of \n to avoid any platform dependency.

Line separators might vary depending on the OS used:

1. \n - *nix systems
2. \r\n - Windows systems