Java IO.pdf - Nguyen Dang Binh

Figure 8.1. Data moving between threads with piped streams
public class PipedInputStream extends InputStream
public class PipedOutputStream extends OutputStream
The PipedInputStream class has two constructors:
public PipedInputStream()
public PipedInputStream(PipedOutputStream source) throws IOException
Java I/O
The no-argument constructor creates a piped input stream that is not yet connected to a piped
output stream. The second constructor creates a piped input stream that's connected to the
piped output stream source.
The PipedOutputStream class also has two constructors:
public PipedOutputStream(PipedInputStream sink) throws IOException
public PipedOutputStream()
The no-argument constructor creates a piped output stream that is not yet connected to a piped
input stream. The second constructor creates a piped output stream that's connected to the
piped input stream sink.
Piped streams are normally created in pairs. The piped output stream becomes the underlying
source for the piped input stream. For example:
PipedOutputStream pout = new PipedOutputStream();
PipedInputStream pin = new PipedInputStream(pout);
This simple example is a little deceptive, because these lines of code will normally be in
different methods and perhaps even different classes. Some mechanism must be established to
pass a reference to the PipedOutputStream into the thread that handles the
PipedInputStream. Or you can create them in the same thread, then pass a reference to the
connected stream into a separate thread. Alternately, you can reverse the order:
PipedInputStream pin = new PipedInputStream();
PipedOutputStream pout = new PipedOutputStream(pin);
Or you can create them both unconnected, then use one or the other's connect() method to
link them:
PipedInputStream pin = new PipedInputStream();
PipedOutputStream pout = new PipedOutputStream();
pin.connect(pout);
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