LineInputStream supports reading CRLF terminated lines that
contain only US-ASCII characters from an input stream. Provides
functionality that is similar to the deprecated
DataInputStream.readLine(). Expected use is to read
lines as String objects from an IMAP/SMTP/etc. stream.
This class also supports UTF-8 data by calling the appropriate
constructor. Or, if the System property mail.mime.allowutf8
is set to true, an attempt will be made to interpret the data as UTF-8,
falling back to treating it as an 8-bit charset if that fails.
Read a line containing only ASCII characters from the input
stream. A line is terminated by a CR or NL or CR-NL sequence.
A common error is a CR-CR-NL sequence, which will also terminate
The line terminator is not returned as part of the returned
String. Returns null if no data is available.