Instances of this class are returned to applications for the purpose of sending user data for a HTTP POST or PUT
request. This class is used when the content-length will be specified in the header of the request. The semantics of
ByteArrayOutputStream are extended so that when close() is called, it is no longer possible to write additional data
to the stream. From this point the content length of the request is fixed and cannot change.
Resets the count field of this output stream to zero, so that all currently accumulated output in
the ouput stream is discarded. The output stream can be used again, reusing the already allocated buffer space.
If the output stream has been closed, then this method has no effect.