public class PipedInputStream extends InputStream
PipedInputStream
object by one thread and data is written
to the corresponding PipedOutputStream
by some other thread. Attempting to use
both objects from a single thread is not
recommended, as it may deadlock the thread.
The piped input stream contains a buffer,
decoupling read operations from write operations,
within limits.
A pipe is said to be broken if a
thread that was providing data bytes to the connected
piped output stream is no longer alive.PipedOutputStream| Modifier and Type | Field and Description |
|---|---|
protected byte[] |
buffer
The circular buffer into which incoming data is placed.
|
protected int |
in
The index of the position in the circular buffer at which the
next byte of data will be stored when received from the connected
piped output stream.
|
protected int |
out
The index of the position in the circular buffer at which the next
byte of data will be read by this piped input stream.
|
protected static int |
PIPE_SIZE
The default size of the pipe's circular input buffer.
|
| Constructor and Description |
|---|
PipedInputStream()
Creates a
PipedInputStream so
that it is not yet connected. |
PipedInputStream(int pipeSize)
Creates a
PipedInputStream so that it is not yet
connected and
uses the specified pipe size for the pipe's buffer. |
PipedInputStream(PipedOutputStream src)
Creates a
PipedInputStream so
that it is connected to the piped output
stream src. |
PipedInputStream(PipedOutputStream src,
int pipeSize)
Creates a
PipedInputStream so that it is
connected to the piped output stream
src and uses the specified pipe size for
the pipe's buffer. |
| Modifier and Type | Method and Description |
|---|---|
int |
available()
Returns the number of bytes that can be read from this input
stream without blocking.
|
void |
close()
Closes this piped input stream and releases any system resources
associated with the stream.
|
void |
connect(PipedOutputStream src)
Causes this piped input stream to be connected
to the piped output stream
src. |
int |
read()
Reads the next byte of data from this piped input stream.
|
int |
read(byte[] b,
int off,
int len)
Reads up to
len bytes of data from this piped input
stream into an array of bytes. |
protected void |
receive(int b)
Receives a byte of data.
|
mark, markSupported, read, reset, skipprotected static final int PIPE_SIZE
protected byte[] buffer
protected int in
in<0 implies the buffer is empty,
in==out implies the buffer is fullprotected int out
public PipedInputStream(PipedOutputStream src) throws IOException
PipedInputStream so
that it is connected to the piped output
stream src. Data bytes written
to src will then be available
as input from this stream.src - the stream to connect to.IOException - if an I/O error occurs.public PipedInputStream(PipedOutputStream src, int pipeSize) throws IOException
PipedInputStream so that it is
connected to the piped output stream
src and uses the specified pipe size for
the pipe's buffer.
Data bytes written to src will then
be available as input from this stream.src - the stream to connect to.pipeSize - the size of the pipe's buffer.IOException - if an I/O error occurs.IllegalArgumentException - if pipeSize <= 0.public PipedInputStream()
public PipedInputStream(int pipeSize)
PipedInputStream so that it is not yet
connected and
uses the specified pipe size for the pipe's buffer.
It must be connected to a PipedOutputStream before being used.pipeSize - the size of the pipe's buffer.IllegalArgumentException - if pipeSize <= 0.public void connect(PipedOutputStream src) throws IOException
src.
If this object is already connected to some
other piped output stream, an IOException
is thrown.
If src is an
unconnected piped output stream and snk
is an unconnected piped input stream, they
may be connected by either the call:
snk.connect(src) or the call:
src.connect(snk) The two calls have the same effect.
src - The piped output stream to connect to.IOException - if an I/O error occurs.protected void receive(int b)
throws IOException
b - the byte being receivedIOException - If the pipe is broken,
unconnected,
closed, or if an I/O error occurs.public int read()
throws IOException
int in the range
0 to 255.
This method blocks until input data is available, the end of the
stream is detected, or an exception is thrown.read in class InputStream-1 if the end of the
stream is reached.IOException - if the pipe is
unconnected,
broken, closed,
or if an I/O error occurs.public int read(byte[] b,
int off,
int len)
throws IOException
len bytes of data from this piped input
stream into an array of bytes. Less than len bytes
will be read if the end of the data stream is reached or if
len exceeds the pipe's buffer size.
If len is zero, then no bytes are read and 0 is returned;
otherwise, the method blocks until at least 1 byte of input is
available, end of the stream has been detected, or an exception is
thrown.read in class InputStreamb - the buffer into which the data is read.off - the start offset in the destination array blen - the maximum number of bytes read.-1 if there is no more data because the end of
the stream has been reached.NullPointerException - If b is null.IndexOutOfBoundsException - If off is negative,
len is negative, or len is greater than
b.length - offIOException - if the pipe is broken,
unconnected,
closed, or if an I/O error occurs.InputStream.read()public int available()
throws IOException
available in class InputStream0 if this input stream has been
closed by invoking its close() method, or if the pipe
is unconnected, or
broken.IOException - if an I/O error occurs.public void close()
throws IOException
close in interface Closeableclose in interface AutoCloseableclose in class InputStreamIOException - if an I/O error occurs.