The PipedReader class is used to read the contents of a pipe as a stream of characters. This class is used generally to read text.
PipedReader class must be connected to the same PipedWriter and are used by different threads.

The PipedWriter class is used to write java pipe as a stream of characters. This class is used generally for writing text. Generally PipedWriter is connected to a PipedReader and used by different threads.