javax.imageio.stream.ImageInputStreamImpl
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JavaTM 2 Platform Standard Ed. 5.0 |
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java.lang.Object
public abstract class ImageInputStreamImpl
An abstract class implementing the ImageInputStream interface.
This class is designed to reduce the number of methods that must
be implemented by subclasses.
In particular, this class handles most or all of the details of byte order interpretation, buffering, mark/reset, discarding, closing, and disposing.
| Field Summary | |
|---|---|
protected int |
bitOffset
The current bit offset within the stream. |
protected ByteOrder |
byteOrder
The byte order of the stream as an instance of the enumeration class java.nio.ByteOrder, where
ByteOrder.BIG_ENDIAN indicates network byte order
and ByteOrder.LITTLE_ENDIAN indicates the reverse
order. |
protected long |
flushedPos
The position prior to which data may be discarded. |
protected long |
streamPos
The current read position within the stream. |
| Constructor Summary | |
|---|---|
ImageInputStreamImpl()
Constructs an ImageInputStreamImpl. |
|
| Method Summary | |
|---|---|
protected void |
checkClosed()
Throws an IOException if the stream has been closed. |
void |
close()
Closes the stream. |
protected void |
finalize()
Finalizes this object prior to garbage collection. |
void |
flush()
Discards the initial position of the stream prior to the current stream position. |
void |
flushBefore(long pos)
Discards the initial portion of the stream prior to the indicated postion. |
int |
getBitOffset()
Returns the current bit offset, as an integer between 0 and 7, inclusive. |
ByteOrder |
getByteOrder()
Returns the byte order with which data values will be read from this stream as an instance of the java.nio.ByteOrder enumeration. |
long |
getFlushedPosition()
Returns the earliest position in the stream to which seeking may be performed. |
long |
getStreamPosition()
Returns the current byte position of the stream. |
boolean |
isCached()
Default implementation returns false. |
boolean |
isCachedFile()
Default implementation returns false. |
boolean |
isCachedMemory()
Default implementation returns false. |
long |
length()
Returns -1L to indicate that the stream has unknown
length. |
void |
mark()
Pushes the current stream position onto a stack of marked positions. |
abstract int |
read()
Reads a single byte from the stream and returns it as an integer between 0 and 255. |
int |
read(byte[] b)
A convenience method that calls read(b, 0, b.length). |
abstract int |
read(byte[] b,
int off,
int len)
Reads up to len bytes from the stream, and stores
them into b starting at index off. |
int |
readBit()
Reads a single bit from the stream and returns it as an int with the value 0 or
1. |
long |
readBits(int numBits)
Reads a bitstring from the stream and returns it as a long, with the first bit read becoming the most
significant bit of the output. |
boolean |
readBoolean()
Reads one input byte and returns true if that byte is nonzero,
false if that byte is zero. |
byte |
readByte()
Reads and returns one input byte. |
void |
readBytes(IIOByteBuffer buf,
int len)
Reads up to len bytes from the stream, and
modifies the supplied IIOByteBuffer to indicate
the byte array, offset, and length where the data may be found. |
char |
readChar()
Reads an input char and returns the char value. |
double |
readDouble()
Reads eight input bytes and returns a double value. |
float |
readFloat()
Reads four input bytes and returns a float value. |
void |
readFully(byte[] b)
Reads some bytes from an input stream and stores them into the buffer array b. |
void |
readFully(byte[] b,
int off,
int len)
Reads len
bytes from
an input stream. |
void |
readFully(char[] c,
int off,
int len)
Reads len chars (unsigned 16-bit integers) from the
stream according to the current byte order, and
stores them into c starting at index
off. |
void |
readFully(double[] d,
int off,
int len)
Reads len doubles (64-bit IEEE double-precision
floats) from the stream according to the current byte order,
and stores them into d starting at
index off. |
void |
readFully(float[] f,
int off,
int len)
Reads len floats (32-bit IEEE single-precision
floats) from the stream according to the current byte order,
and stores them into f starting at
index off. |
void |
readFully(int[] i,
int off,
int len)
Reads len ints (signed 32-bit integers) from the
stream according to the current byte order, and
stores them into i starting at index
off. |
void |
readFully(long[] l,
int off,
int len)
Reads len longs (signed 64-bit integers) from the
stream according to the current byte order, and
stores them into l starting at index
off. |
void |
readFully(short[] s,
int off,
int len)
Reads len shorts (signed 16-bit integers) from the
stream according to the current byte order, and
stores them into s starting at index
off. |
int |
readInt()
Reads four input bytes and returns an int value. |
String |
readLine()
Reads the next line of text from the input stream. |
long |
readLong()
Reads eight input bytes and returns a long value. |
short |
readShort()
Reads two input bytes and returns a short value. |
int |
readUnsignedByte()
Reads one input byte, zero-extends it to type int, and returns
the result, which is therefore in the range
0
through 255. |
long |
readUnsignedInt()
Reads 4 bytes from the stream, and (conceptually) concatenates them according to the current byte order, converts the result to a long, masks it with 0xffffffffL in order to
strip off any sign-extension bits, and returns the result as an
unsigned long value. |
int |
readUnsignedShort()
Reads two input bytes and returns an int value in the range 0
through 65535. |
String |
readUTF()
Reads in a string that has been encoded using a modified UTF-8 format. |
void |
reset()
Resets the current stream byte and bit positions from the stack of marked positions. |
void |
seek(long pos)
Sets the current stream position to the desired location. |
void |
setBitOffset(int bitOffset)
Sets the bit offset to an integer between 0 and 7, inclusive. |
void |
setByteOrder(ByteOrder byteOrder)
Sets the desired byte order for future reads of data values from this stream. |
int |
skipBytes(int n)
Advances the current stream position by calling seek(getStreamPosition() + n). |
long |
skipBytes(long n)
Advances the current stream position by calling seek(getStreamPosition() + n). |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
|---|
protected ByteOrder byteOrder
java.nio.ByteOrder, where
ByteOrder.BIG_ENDIAN indicates network byte order
and ByteOrder.LITTLE_ENDIAN indicates the reverse
order. By default, the value is
ByteOrder.BIG_ENDIAN.
protected long streamPos
protected int bitOffset
protected long flushedPos
flushedPos
will always be >= 0.
| Constructor Detail |
|---|
public ImageInputStreamImpl()
ImageInputStreamImpl.
| Method Detail |
|---|
protected final void checkClosed()
throws IOException
IOException if the stream has been closed.
Subclasses may call this method from any of their methods that
require the stream not to be closed.
IOException - if the stream is closed.public void setByteOrder(ByteOrder byteOrder)
ImageInputStream The enumeration class java.nio.ByteOrder is
used to specify the byte order. A value of
ByteOrder.BIG_ENDIAN specifies so-called
big-endian or network byte order, in which the high-order byte
comes first. Motorola and Sparc processors store data in this
format, while Intel processors store data in the reverse
ByteOrder.LITTLE_ENDIAN order.
The byte order has no effect on the results returned from
the readBits method (or the value written by
ImageOutputStream.writeBits).
setByteOrder in interface ImageInputStreambyteOrder - one of ByteOrder.BIG_ENDIAN or
java.nio.ByteOrder.LITTLE_ENDIAN, indicating whether
network byte order or its reverse will be used for future
reads.ByteOrder,
ImageInputStream.getByteOrder(),
ImageInputStream.readBits(int)public ByteOrder getByteOrder()
ImageInputStreamjava.nio.ByteOrder enumeration.
getByteOrder in interface ImageInputStreamByteOrder.BIG_ENDIAN or
ByteOrder.LITTLE_ENDIAN, indicating which byte
order is being used.ByteOrder,
ImageInputStream.setByteOrder(java.nio.ByteOrder)
public abstract int read()
throws IOException
ImageInputStreamThe bit offset within the stream is reset to zero before the read occurs.
read in interface ImageInputStreamIOException - if an I/O error occurs.
public int read(byte[] b)
throws IOException
read(b, 0, b.length).
The bit offset within the stream is reset to zero before the read occurs.
read in interface ImageInputStreamb - an array of bytes to be written to.
-1
to indicate EOF.
NullPointerException - if b is
null.
IOException - if an I/O error occurs.
public abstract int read(byte[] b,
int off,
int len)
throws IOException
len bytes from the stream, and stores
them into b starting at index off.
If no bytes can be read because the end of the stream has been
reached, -1 is returned.
The bit offset within the stream must be reset to zero before the read occurs.
Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.
read in interface ImageInputStreamb - an array of bytes to be written to.off - the starting position within b to write to.len - the maximum number of bytes to read.
-1
to indicate EOF.
IndexOutOfBoundsException - if off is
negative, len is negative, or off +
len is greater than b.length.
NullPointerException - if b is
null.
IOException - if an I/O error occurs.
public void readBytes(IIOByteBuffer buf,
int len)
throws IOException
ImageInputStreamlen bytes from the stream, and
modifies the supplied IIOByteBuffer to indicate
the byte array, offset, and length where the data may be found.
The caller should not attempt to modify the data found in the
IIOByteBuffer.
The bit offset within the stream is reset to zero before the read occurs.
readBytes in interface ImageInputStreambuf - an IIOByteBuffer object to be modified.len - the maximum number of bytes to read.
IOException - if an I/O error occurs.
public boolean readBoolean()
throws IOException
DataInputtrue if that byte is nonzero,
false if that byte is zero.
This method is suitable for reading
the byte written by the writeBoolean
method of interface DataOutput.
readBoolean in interface DataInputreadBoolean in interface ImageInputStreamboolean value read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.
public byte readByte()
throws IOException
DataInput-128 through 127,
inclusive.
This method is suitable for
reading the byte written by the writeByte
method of interface DataOutput.
readByte in interface DataInputreadByte in interface ImageInputStreamEOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.
public int readUnsignedByte()
throws IOException
DataInputint, and returns
the result, which is therefore in the range
0
through 255.
This method is suitable for reading
the byte written by the writeByte
method of interface DataOutput
if the argument to writeByte
was intended to be a value in the range
0 through 255.
readUnsignedByte in interface DataInputreadUnsignedByte in interface ImageInputStreamEOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.
public short readShort()
throws IOException
DataInputshort value. Let a
be the first byte read and b
be the second byte. The value
returned
is:
(short)((a << 8) | (b & 0xff))
writeShort method of
interface DataOutput.
readShort in interface DataInputreadShort in interface ImageInputStreamEOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.ImageInputStream.getByteOrder()
public int readUnsignedShort()
throws IOException
DataInputint value in the range 0
through 65535. Let a
be the first byte read and
b
be the second byte. The value returned is:
(((a & 0xff) << 8) | (b & 0xff))
writeShort method
of interface DataOutput if
the argument to writeShort
was intended to be a value in the range
0 through 65535.
readUnsignedShort in interface DataInputreadUnsignedShort in interface ImageInputStreamEOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.ImageInputStream.getByteOrder()
public char readChar()
throws IOException
DataInputchar and returns the char value.
A Unicode char is made up of two bytes.
Let a
be the first byte read and b
be the second byte. The value
returned is:
(char)((a << 8) | (b & 0xff))
writeChar method of interface
DataOutput.
readChar in interface DataInputreadChar in interface ImageInputStreamchar read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.ImageInputStream.readUnsignedShort()
public int readInt()
throws IOException
DataInputint value. Let a
be the first byte read, b be
the second byte, c be the third
byte,
and d be the fourth
byte. The value returned is:
(((a & 0xff) << 24) | ((b & 0xff) << 16) |
((c & 0xff) << 8) | (d & 0xff))
This method is suitable
for reading bytes written by the writeInt
method of interface DataOutput.
readInt in interface DataInputreadInt in interface ImageInputStreamint value read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.ImageInputStream.getByteOrder()
public long readUnsignedInt()
throws IOException
ImageInputStream0xffffffffL in order to
strip off any sign-extension bits, and returns the result as an
unsigned long value.
The bit offset within the stream is reset to zero before the read occurs.
readUnsignedInt in interface ImageInputStreamEOFException - if the stream reaches the end before
reading all the bytes.
IOException - if an I/O error occurs.ImageInputStream.getByteOrder()
public long readLong()
throws IOException
DataInputlong value. Let a
be the first byte read, b be
the second byte, c be the third
byte, d
be the fourth byte,
e be the fifth byte, f
be the sixth byte, g be the
seventh byte,
and h be the
eighth byte. The value returned is:
(((long)(a & 0xff) << 56) |
((long)(b & 0xff) << 48) |
((long)(c & 0xff) << 40) |
((long)(d & 0xff) << 32) |
((long)(e & 0xff) << 24) |
((long)(f & 0xff) << 16) |
((long)(g & 0xff) << 8) |
((long)(h & 0xff)))
This method is suitable
for reading bytes written by the writeLong
method of interface DataOutput.
readLong in interface DataInputreadLong in interface ImageInputStreamlong value read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.ImageInputStream.getByteOrder()
public float readFloat()
throws IOException
DataInputfloat value. It does this
by first constructing an int
value in exactly the manner
of the readInt
method, then converting this int
value to a float in
exactly the manner of the method Float.intBitsToFloat.
This method is suitable for reading
bytes written by the writeFloat
method of interface DataOutput.
readFloat in interface DataInputreadFloat in interface ImageInputStreamfloat value read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.ImageInputStream.getByteOrder()
public double readDouble()
throws IOException
DataInputdouble value. It does this
by first constructing a long
value in exactly the manner
of the readlong
method, then converting this long
value to a double in exactly
the manner of the method Double.longBitsToDouble.
This method is suitable for reading
bytes written by the writeDouble
method of interface DataOutput.
readDouble in interface DataInputreadDouble in interface ImageInputStreamdouble value read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.ImageInputStream.getByteOrder()
public String readLine()
throws IOException
DataInputString. Note
that because this
method processes bytes,
it does not support input of the full Unicode
character set.
If end of file is encountered
before even one byte can be read, then null
is returned. Otherwise, each byte that is
read is converted to type char
by zero-extension. If the character '\n'
is encountered, it is discarded and reading
ceases. If the character '\r'
is encountered, it is discarded and, if
the following byte converts to the
character '\n', then that is
discarded also; reading then ceases. If
end of file is encountered before either
of the characters '\n' and
'\r' is encountered, reading
ceases. Once reading has ceased, a String
is returned that contains all the characters
read and not discarded, taken in order.
Note that every character in this string
will have a value less than \u0100,
that is, (char)256.
readLine in interface DataInputreadLine in interface ImageInputStreamnull if the end of file is
encountered before a byte can be read.
IOException - if an I/O error occurs.
public String readUTF()
throws IOException
DataInputreadUTF
is that it reads a representation of a Unicode
character string encoded in modified
UTF-8 format; this string of characters
is then returned as a String.
First, two bytes are read and used to
construct an unsigned 16-bit integer in
exactly the manner of the readUnsignedShort
method . This integer value is called the
UTF length and specifies the number
of additional bytes to be read. These bytes
are then converted to characters by considering
them in groups. The length of each group
is computed from the value of the first
byte of the group. The byte following a
group, if any, is the first byte of the
next group.
If the first byte of a group
matches the bit pattern 0xxxxxxx
(where x means "may be 0
or 1"), then the group consists
of just that byte. The byte is zero-extended
to form a character.
If the first byte
of a group matches the bit pattern 110xxxxx,
then the group consists of that byte a
and a second byte b. If there
is no byte b (because byte
a was the last of the bytes
to be read), or if byte b does
not match the bit pattern 10xxxxxx,
then a UTFDataFormatException
is thrown. Otherwise, the group is converted
to the character:
(char)(((a& 0x1F) << 6) | (b & 0x3F))
1110xxxx,
then the group consists of that byte a
and two more bytes b and c.
If there is no byte c (because
byte a was one of the last
two of the bytes to be read), or either
byte b or byte c
does not match the bit pattern 10xxxxxx,
then a UTFDataFormatException
is thrown. Otherwise, the group is converted
to the character:
(char)(((a & 0x0F) << 12) | ((b & 0x3F) << 6) | (c & 0x3F))
1111xxxx or the pattern
10xxxxxx, then a UTFDataFormatException
is thrown.
If end of file is encountered
at any time during this entire process,
then an EOFException is thrown.
After every group has been converted to
a character by this process, the characters
are gathered, in the same order in which
their corresponding groups were read from
the input stream, to form a String,
which is returned.
The writeUTF
method of interface DataOutput
may be used to write data that is suitable
for reading by this method.
readUTF in interface DataInputreadUTF in interface ImageInputStreamEOFException - if this stream reaches the end
before reading all the bytes.
IOException - if an I/O error occurs.
UTFDataFormatException - if the bytes do not represent a
valid modified UTF-8 encoding of a string.
public void readFully(byte[] b,
int off,
int len)
throws IOException
DataInputlen
bytes from
an input stream.
This method blocks until one of the following conditions occurs:
len bytes
of input data are available, in which case
a normal return is made.
EOFException
is thrown.
IOException other
than EOFException 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. Otherwise, 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.
readFully in interface DataInputreadFully in interface ImageInputStreamb - the buffer into which the data is read.off - an int specifying the offset into the data.len - an int specifying the number of bytes to read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.
public void readFully(byte[] b)
throws IOException
DataInputb. The number of bytes
read is equal
to the length of b.
This method blocks until one of the following conditions occurs:
b.length
bytes of input data are available, in which
case a normal return is made.
EOFException
is thrown.
IOException other
than EOFException is thrown.
If b is null,
a NullPointerException is thrown.
If b.length is zero, then
no bytes are read. Otherwise, the first
byte read is stored into element b[0],
the next one into b[1], and
so on.
If an exception is thrown from
this method, then it may be that some but
not all bytes of b have been
updated with data from the input stream.
readFully in interface DataInputreadFully in interface ImageInputStreamb - the buffer into which the data is read.
EOFException - if this stream reaches the end before reading
all the bytes.
IOException - if an I/O error occurs.
public void readFully(short[] s,
int off,
int len)
throws IOException
ImageInputStreamlen shorts (signed 16-bit integers) from the
stream according to the current byte order, and
stores them into s starting at index
off. If the end of the stream is reached, an
EOFException will be thrown.
The bit offset within the stream is reset to zero before the read occurs.
readFully in interface ImageInputStreams - an array of shorts to be written to.off - the starting position withinb to write to.len - the maximum number of shorts to read.
EOFException - if the stream reaches the end before
reading all the bytes.
IOException - if an I/O error occurs.
public void readFully(char[] c,
int off,
int len)
throws IOException
ImageInputStreamlen chars (unsigned 16-bit integers) from the
stream according to the current byte order, and
stores them into c starting at index
off. If the end of the stream is reached, an
EOFException will be thrown.
The bit offset within the stream is reset to zero before the read occurs.
readFully in interface ImageInputStreamc - an array of chars to be written to.off - the starting position withinb to write to.len - the maximum number of chars to read.
EOFException - if the stream reaches the end before
reading all the bytes.
IOException - if an I/O error occurs.
public void readFully(int[] i,
int off,
int len)
throws IOException
ImageInputStreamlen ints (signed 32-bit integers) from the
stream according to the current byte order, and
stores them into i starting at index
off. If the end of the stream is reached, an
EOFException will be thrown.
The bit offset within the stream is reset to zero before the read occurs.
readFully in interface ImageInputStreami - an array of ints to be written to.off - the starting position withinb to write to.len - the maximum number of ints to read.
EOFException - if the stream reaches the end before
reading all the bytes.
IOException - if an I/O error occurs.
public void readFully(long[] l,
int off,
int len)
throws IOException
ImageInputStreamlen longs (signed 64-bit integers) from the
stream according to the current byte order, and
stores them into l starting at index
off. If the end of the stream is reached, an
EOFException will be thrown.
The bit offset within the stream is reset to zero before the read occurs.
readFully in interface ImageInputStreaml - an array of longs to be written to.off - the starting position withinb to write to.len - the maximum number of longs to read.
EOFException - if the stream reaches the end before
reading all the bytes.
IOException - if an I/O error occurs.
public void readFully(float[] f,
int off,
int len)
throws IOException
ImageInputStreamlen floats (32-bit IEEE single-precision
floats) from the stream according to the current byte order,
and stores them into f starting at
index off. If the end of the stream is reached,
an EOFException will be thrown.
The bit offset within the stream is reset to zero before the read occurs.
readFully in interface ImageInputStreamf - an array of floats to be written to.off - the starting position withinb to write to.len - the maximum number of floats to read.
EOFException - if the stream reaches the end before
reading all the bytes.
IOException - if an I/O error occurs.
public void readFully(double[] d,
int off,
int len)
throws IOException
ImageInputStreamlen doubles (64-bit IEEE double-precision
floats) from the stream according to the current byte order,
and stores them into d starting at
index off. If the end of the stream is reached,
an EOFException will be thrown.
The bit offset within the stream is reset to zero before the read occurs.
readFully in interface ImageInputStreamd - an array of doubles to be written to.off - the starting position withinb to write to.len - the maximum number of doubles to read.
EOFException - if the stream reaches the end before
reading all the bytes.
IOException - if an I/O error occurs.
public long getStreamPosition()
throws IOException
ImageInputStream
getStreamPosition in interface ImageInputStreamIOException - if an I/O error occurs.
public int getBitOffset()
throws IOException
ImageInputStreamreadBits method. A value of 0 indicates the
most-significant bit, and a value of 7 indicates the least
significant bit, of the byte being read.
The bit offset is set to 0 when a stream is first
opened, and is reset to 0 by calls to seek,
skipBytes, or any read or
readFully method.
getBitOffset in interface ImageInputStreamint containing the bit offset between
0 and 7, inclusive.
IOException - if an I/O error occurs.ImageInputStream.setBitOffset(int)
public void setBitOffset(int bitOffset)
throws IOException
ImageInputStreamgetStreamPosition, is left unchanged.
A value of 0 indicates the
most-significant bit, and a value of 7 indicates the least
significant bit, of the byte being read.
setBitOffset in interface ImageInputStreambitOffset - the desired offset, as an int
between 0 and 7, inclusive.
IOException - if an I/O error occurs.ImageInputStream.getBitOffset()
public int readBit()
throws IOException
ImageInputStreamint with the value 0 or
1. The bit offset is advanced by one and reduced
modulo 8.
readBit in interface ImageInputStreamint containing the value 0
or 1.
EOFException - if the stream reaches the end before
reading all the bits.
IOException - if an I/O error occurs.
public long readBits(int numBits)
throws IOException
ImageInputStreamlong, with the first bit read becoming the most
significant bit of the output. The read starts within the byte
indicated by getStreamPosition, at the bit given
by getBitOffset. The bit offset is advanced by
numBits and reduced modulo 8.
The byte order of the stream has no effect on this method. The return value of this method is constructed as though the bits were read one at a time, and shifted into the right side of the return value, as shown by the following pseudo-code:
long accum = 0L;
for (int i = 0; i < numBits; i++) {
accum <<= 1; // Shift left one bit to make room
accum |= readBit();
}
Note that the result of readBits(32) may thus not
be equal to that of readInt() if a reverse network
byte order is being used (i.e., getByteOrder() ==
false).
If the end of the stream is encountered before all the bits
have been read, an EOFException is thrown.
readBits in interface ImageInputStreamnumBits - the number of bits to read, as an int
between 0 and 64, inclusive.
long with the last bit
read stored in the least significant bit.
EOFException - if the stream reaches the end before
reading all the bits.
IOException - if an I/O error occurs.public long length()
-1L to indicate that the stream has unknown
length. Subclasses must override this method to provide actual
length information.
length in interface ImageInputStream
public int skipBytes(int n)
throws IOException
seek(getStreamPosition() + n).
The bit offset is reset to zero.
skipBytes in interface DataInputskipBytes in interface ImageInputStreamn - the number of bytes to seek forward.
int representing the number of bytes
skipped.
IOException - if getStreamPosition
throws an IOException when computing either
the starting or ending position.
public long skipBytes(long n)
throws IOException
seek(getStreamPosition() + n).
The bit offset is reset to zero.
skipBytes in interface ImageInputStreamn - the number of bytes to seek forward.
long representing the number of bytes
skipped.
IOException - if getStreamPosition
throws an IOException when computing either
the starting or ending position.
public void seek(long pos)
throws IOException
ImageInputStream An IndexOutOfBoundsException will be thrown if
pos is smaller than the flushed position (as
returned by getflushedPosition).
It is legal to seek past the end of the file; an
EOFException will be thrown only if a read is
performed.
seek in interface ImageInputStreampos - a long containing the desired file
pointer position.
IOException - if any other I/O error occurs.public void mark()
mark in interface ImageInputStream
public void reset()
throws IOException
An IOException will be thrown if the previous
marked position lies in the discarded portion of the stream.
reset in interface ImageInputStreamIOException - if an I/O error occurs.
public void flushBefore(long pos)
throws IOException
ImageInputStreamIndexOutOfBoundsException.
Calling flushBefore may allow classes
implementing this interface to free up resources such as memory
or disk space that are being used to store data from the
stream.
flushBefore in interface ImageInputStreampos - a long containing the length of the
file prefix that may be flushed.
IOException - if an I/O error occurs.
public void flush()
throws IOException
ImageInputStreamflushBefore(getStreamPosition()).
flush in interface ImageInputStreamIOException - if an I/O error occurs.public long getFlushedPosition()
ImageInputStreamflushBefore.
getFlushedPosition in interface ImageInputStreamlong.public boolean isCached()
isCached in interface ImageInputStreamtrue if this ImageInputStream
caches data.ImageInputStream.isCachedMemory(),
ImageInputStream.isCachedFile()public boolean isCachedMemory()
isCachedMemory in interface ImageInputStreamtrue if this ImageInputStream
caches data in main memory.ImageInputStream.isCached(),
ImageInputStream.isCachedFile()public boolean isCachedFile()
isCachedFile in interface ImageInputStreamtrue if this ImageInputStream
caches data in a temporary file.ImageInputStream.isCached(),
ImageInputStream.isCachedMemory()
public void close()
throws IOException
ImageInputStreamIOExceptions or incorrect
behavior. Calling this method may allow classes implementing
this interface to release resources associated with the stream
such as memory, disk space, or file descriptors.
close in interface ImageInputStreamIOException - if an I/O error occurs.
protected void finalize()
throws Throwable
close method is called to close any open input
source. This method should not be called from application
code.
finalize in class ObjectThrowable - if an error occurs during superclass
finalization.
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Copyright 2004 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.