Reads a line.
public String readLine()
Returns the next line from the input stream, or returns null if the end of the input stream is reached.
A line is defined as a sequence of characters followed by a carriage return (\r), a line feed (\n), or a carriage return immediately followed by a line feed. The resulting string does not contain the terminating carriage return and/or line feed.
Overrides Reader.readLine