public class SeekableStreamAdapter extends SeekableStream
markPos
Constructor and Description |
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SeekableStreamAdapter(javax.imageio.stream.ImageInputStream iin)
Main constructor
|
Modifier and Type | Method and Description |
---|---|
boolean |
canSeekBackwards()
Returns
true if this object supports calls to
seek(pos) with an offset pos smaller
than the current offset, as returned by getFilePointer . |
long |
getFilePointer()
Returns the current offset in this stream.
|
int |
read()
Reads the next byte of data from the input stream.
|
int |
read(byte[] b,
int off,
int len)
Reads up to
len bytes of data from the input stream into
an array of bytes. |
void |
seek(long pos)
Sets the offset, measured from the beginning of this
stream, at which the next read occurs.
|
int |
skipBytes(int n)
Attempts to skip over
n bytes of input discarding the
skipped bytes. |
finalize, mark, markSupported, readBoolean, readByte, readChar, readCharLE, readDouble, readDoubleLE, readFloat, readFloatLE, readFully, readFully, readInt, readIntLE, readLine, readLong, readLongLE, readShort, readShortLE, readUnsignedByte, readUnsignedInt, readUnsignedIntLE, readUnsignedShort, readUnsignedShortLE, readUTF, reset, wrapInputStream
public SeekableStreamAdapter(javax.imageio.stream.ImageInputStream iin)
iin
- the ImageInputStream to operate onpublic long getFilePointer() throws java.io.IOException
getFilePointer
in class SeekableStream
java.io.IOException
- if an I/O error occurs.public int read() throws java.io.IOException
int
in the range 0
to
255
. If no byte is available because the end of the stream
has been reached, the value -1
is returned. This method
blocks until input data is available, the end of the stream is detected,
or an exception is thrown.
A subclass must provide an implementation of this method.
read
in class SeekableStream
-1
if the end of the
stream is reached.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. An attempt is made to read as many as
len
bytes, but a smaller number may be read, possibly
zero. The number of bytes actually read is returned as an integer.
This method blocks until input data is available, end of stream is detected, or an exception is thrown.
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
stream, 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
stream, then an IOException
is thrown. In particular, an
IOException
is thrown if the input stream has been closed.
A subclass must provide an implementation of this method.
read
in class SeekableStream
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.public void seek(long pos) throws java.io.IOException
If canSeekBackwards()
returns false
,
then setting pos
to an offset smaller than
the current value of getFilePointer()
will have
no effect.
seek
in class SeekableStream
pos
- the offset position, measured in bytes from the
beginning of the stream, at which to set the stream
pointer.java.io.IOException
- if pos
is less than
0
or if an I/O error occurs.public boolean canSeekBackwards()
true
if this object supports calls to
seek(pos)
with an offset pos
smaller
than the current offset, as returned by getFilePointer
.canSeekBackwards
in class SeekableStream
public int skipBytes(int n) throws java.io.IOException
n
bytes of input discarding the
skipped bytes.
This method may skip over some smaller number of bytes, possibly zero.
This may result from any of a number of conditions; reaching end of
stream before n
bytes have been skipped is only one
possibility. This method never throws an EOFException
.
The actual number of bytes skipped is returned. If n
is negative, no bytes are skipped.
skipBytes
in interface java.io.DataInput
skipBytes
in class SeekableStream
n
- the number of bytes to be skipped.java.io.IOException
- if an I/O error occurs.Copyright 1999-2012 The Apache Software Foundation. All Rights Reserved.