Class PipedInputStream
java.lang.Object
java.io.InputStream
java.io.PipedInputStream
- All Implemented Interfaces:
Closeable
,AutoCloseable
A piped input stream should be connected
to a piped output stream; the piped input
stream then provides whatever data bytes
are written to the piped output stream.
Typically, data is read from a
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.- Since:
- 1.0
- See Also:
-
Field Summary
Modifier and TypeFieldDescriptionprotected byte[]
The circular buffer into which incoming data is placed.protected int
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
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 final int
The default size of the pipe's circular input buffer. -
Constructor Summary
ConstructorDescriptionCreates aPipedInputStream
so that it is not yet connected.PipedInputStream
(int pipeSize) Creates aPipedInputStream
so that it is not yet connected and uses the specified pipe size for the pipe's buffer.Creates aPipedInputStream
so that it is connected to the piped output streamsrc
.PipedInputStream
(PipedOutputStream src, int pipeSize) Creates aPipedInputStream
so that it is connected to the piped output streamsrc
and uses the specified pipe size for the pipe's buffer. -
Method Summary
Modifier and TypeMethodDescriptionint
Returns the number of bytes that can be read from this input stream without blocking.void
close()
Closes this 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 streamsrc
.int
read()
Reads the next byte of data from this piped input stream.int
read
(byte[] b, int off, int len) Reads up tolen
bytes of data from this piped input stream into an array of bytes.protected void
receive
(int b) Receives a byte of data.Methods inherited from class java.io.InputStream
mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo
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Field Details
-
PIPE_SIZE
protected static final int PIPE_SIZEThe default size of the pipe's circular input buffer.- Since:
- 1.1
- See Also:
-
buffer
protected byte[] bufferThe circular buffer into which incoming data is placed.- Since:
- 1.1
-
in
protected int inThe 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.in < 0
implies the buffer is empty,in == out
implies the buffer is full- Since:
- 1.1
-
out
protected int outThe index of the position in the circular buffer at which the next byte of data will be read by this piped input stream.- Since:
- 1.1
-
-
Constructor Details
-
PipedInputStream
Creates aPipedInputStream
so that it is connected to the piped output streamsrc
. Data bytes written tosrc
will then be available as input from this stream.- Parameters:
src
- the stream to connect to.- Throws:
IOException
- if an I/O error occurs.
-
PipedInputStream
Creates aPipedInputStream
so that it is connected to the piped output streamsrc
and uses the specified pipe size for the pipe's buffer. Data bytes written tosrc
will then be available as input from this stream.- Parameters:
src
- the stream to connect to.pipeSize
- the size of the pipe's buffer.- Throws:
IOException
- if an I/O error occurs.IllegalArgumentException
- ifpipeSize <= 0
.- Since:
- 1.6
-
PipedInputStream
-
PipedInputStream
public PipedInputStream(int pipeSize) Creates aPipedInputStream
so that it is not yet connected and uses the specified pipe size for the pipe's buffer. It must be connected to aPipedOutputStream
before being used.- Parameters:
pipeSize
- the size of the pipe's buffer.- Throws:
IllegalArgumentException
- ifpipeSize <= 0
.- Since:
- 1.6
-
-
Method Details
-
connect
Causes this piped input stream to be connected to the piped output streamsrc
. If this object is already connected to some other piped output stream, anIOException
is thrown.If
src
is an unconnected piped output stream andsnk
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.
- Parameters:
src
- The piped output stream to connect to.- Throws:
IOException
- if an I/O error occurs.
-
receive
Receives a byte of data. This method will block if no input is available.- Parameters:
b
- the byte being received- Throws:
IOException
- If the pipe isbroken
,unconnected
, closed, or if an I/O error occurs.- Since:
- 1.1
-
read
Reads the next byte of data from this piped input stream. The value byte is returned as anint
in the range0
to255
. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.- Specified by:
read
in classInputStream
- Returns:
- the next byte of data, or
-1
if the end of the stream is reached. - Throws:
IOException
- if the pipe isunconnected
,broken
, closed, or if an I/O error occurs.
-
read
Reads up tolen
bytes of data from this piped input stream into an array of bytes. Less thanlen
bytes will be read if the end of the data stream is reached or iflen
exceeds the pipe's buffer size. Iflen
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.- Overrides:
read
in classInputStream
- Parameters:
b
- the buffer into which the data is read.off
- the start offset in arrayb
at which the data is written.len
- the maximum number of bytes to read.- Returns:
- the total number of bytes read into the buffer, or
-1
if there is no more data because the end of the stream has been reached. - Throws:
NullPointerException
- Ifb
isnull
.IndexOutOfBoundsException
- Ifoff
is negative,len
is negative, orlen
is greater thanb.length - off
IOException
- if the pipe isbroken
,unconnected
, closed, or if an I/O error occurs.- See Also:
-
available
Returns the number of bytes that can be read from this input stream without blocking.- Overrides:
available
in classInputStream
- Returns:
- the number of bytes that can be read from this input stream
without blocking, or
0
if this input stream has been closed by invoking itsclose()
method, or if the pipe isunconnected
, orbroken
. - Throws:
IOException
- if an I/O error occurs.- Since:
- 1.0.2
-
close
Closes this input stream and releases any system resources associated with the stream.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Overrides:
close
in classInputStream
- Throws:
IOException
- if an I/O error occurs.
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