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OSMQ v2.0.1 |
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java.lang.Objectjava.io.InputStream
java.io.FilterInputStream
osmq.io.PacketInputStream
An input stream filer that supports reading an input stream as packets of bytes. Each packet is preceeded with a size.
Note this class assumes a single reader and is NOT thread safe.
Constructor Summary | |
PacketInputStream(java.io.InputStream in)
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Method Summary | |
int |
getLastPacketSize()
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boolean |
isEOF()
Returns true if the end of the stream was encountered. |
int |
read(byte[] b,
int off,
int len)
Reads len bytes of data from the input stream into
an array of bytes. |
byte[] |
readBytes()
Returns the next packet of bytes from the underlying InputStream into a newly allocated byte array. |
int |
readBytes(byte[] target)
Returns the next packet of bytes from the underlying InputStream and copies them into the byte array passed by the calling function. |
java.lang.String |
readln()
Returns the next packet of bytes from the underlying InputStream returns it as a byte array. |
Methods inherited from class java.io.FilterInputStream |
available, close, mark, markSupported, read, read, reset, skip |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface osmq.io.ReaderStream |
close |
Constructor Detail |
public PacketInputStream(java.io.InputStream in)
Method Detail |
public int readBytes(byte[] target) throws java.io.IOException
readBytes
in interface ReaderStream
java.io.IOException
public boolean isEOF()
public java.lang.String readln() throws java.io.IOException
This method blocks until the next packet is available.
readln
in interface ReaderStream
java.io.IOException
- if an I/O error occurs.public int getLastPacketSize()
public byte[] readBytes() throws java.io.IOException
readBytes
in interface ReaderStream
java.io.IOException
- if an I/O error occurs.public int read(byte[] b, int off, int len) throws java.io.IOException
len
bytes of data from the input stream into
an array of bytes.
The number of bytes actually read is returned as an integer.
NOTE This method blocks until input len
is available,
end of file is detected, or an exception is thrown.
This is differs from the normal non-blocking InputStream contract that
may return less than len
If b
is null
, a
NullPointerException
is thrown.
If off
is negative, or len
is negative, or
off+len
is greater than the length of the array
b
, then an IndexOutOfBoundsException
is
thrown.
If len
is zero, then no bytes are read and
0
is returned; otherwise, there is an attempt to read at
least one byte. If no byte is available because the stream is at end of
file, the value -1
is returned; otherwise, at least one
byte is read and stored into b
.
The first byte read is stored into element b[off]
, the
next one into b[off+1]
, and so on. The number of bytes read
is, at most, equal to len
. Let k be the number of
bytes actually read; these bytes will be stored in elements
b[off]
through b[off+
k-1]
,
leaving elements b[off+
k]
through
b[off+len-1]
unaffected.
In every case, elements b[0]
through
b[off]
and elements b[off+len]
through
b[b.length-1]
are unaffected.
If the first byte cannot be read for any reason other than end of
file, then an IOException
is thrown. In particular, an
IOException
is thrown if the input stream has been closed.
The read(b,
off,
len)
method
for class InputStream
simply calls the method
read()
repeatedly. If the first such call results in an
IOException
, that exception is returned from the call to
the read(b,
off,
len)
method. If
any subsequent call to read()
results in a
IOException
, the exception is caught and treated as if it
were end of file; the bytes read up to that point are stored into
b
and the number of bytes read before the exception
occurred is returned. Subclasses are encouraged to provide a more
efficient implementation of this method.
b
- the buffer into which the data is read.off
- the start offset in array b
at which the data is written.len
- the maximum number of bytes to read.
-1
if there is no more data because the end of
the stream has been reached.
java.io.IOException
- if an I/O error occurs.InputStream.read(byte[], int, int)
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(c) 2000 - 2003 MQue Systems All Rights Reserved |
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