How to find out which line separator BufferedReader#readLine() used to split the line?

Question

I am reading a file via the BufferedReader

String filename = ...
br = new BufferedReader( new FileInputStream(filename));
while (true) {
   String s = br.re         


        

Answer 1

Maybe you could use Scanner instead.

You can pass regular expressions to Scanner#useDelimiter() to set custom delimiter.

String regex="(\r)?\n";
String filename=....;
Scanner scan = new Scanner(new FileInputStream(filename));
scan.useDelimiter(Pattern.compile(regex));
while (scan.hasNext()) {
    String str= scan.next();
    // todo
}

You could use this code below to convert BufferedReader to Scanner

 new Scanner(bufferedReader);

Answer 2

After reading the java docs (I confess to being a pythonista), it seems that there isn't a clean way to determine the line-end encoding used in a specific file.

The best thing I can recommended is that you use BufferedReader.read() and iterate over every character in the file. Something like this:

String filename = ...
br = new BufferedReader( new FileInputStream(filename));
while (true) {
   String l = "";
   Char c = " ";
   while (true){
        c = br.read();
        if not c == "\n"{
            // do stuff, not sure what you want with the endl encoding
            // break to return endl-free line
        }
        if not c == "\r"{
            // do stuff, not sure what you want with the endl encoding
            // break to return endl-free line
            Char ctwo = ' '
            ctwo = br.read();
            if ctwo == "\n"{
                // do extra stuff since you know that you've got a \r\n
            }
        }
        else{
            l = l + c;
        }
   if (l == null) break;
   ...
   l = "";
}

Answer 3

If you happen to be reading this file into a Swing text component then you can just use the JTextComponent.read(...) method to load the file into the Document. Then you can use:

textComponent.getDocument().getProperty( DefaultEditorKit.EndOfLineStringProperty );

to get actual EOL string that was used in the file.