ImageReaders. Various input sources, such as
* InputStreams and Files,
* as well as future fast I/O sources may be "wrapped" by a suitable
* implementation of this interface for use by the Image I/O API.
*
* @see ImageInputStreamImpl
* @see FileImageInputStream
* @see FileCacheImageInputStream
* @see MemoryCacheImageInputStream
*
*/
public interface ImageInputStream extends DataInput, Closeable {
/**
* Sets the desired byte order for future reads of data values
* from this stream. For example, the sequence of bytes '0x01
* 0x02 0x03 0x04' if read as a 4-byte integer would have the
* value '0x01020304' using network byte order and the value
* '0x04030201' under the reverse byte order.
*
* 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).
*
* @param byteOrder 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.
*
* @see java.nio.ByteOrder
* @see #getByteOrder
* @see #readBits(int)
*/
void setByteOrder(ByteOrder byteOrder);
/**
* Returns the byte order with which data values will be read from
* this stream as an instance of the
* java.nio.ByteOrder enumeration.
*
* @return one of ByteOrder.BIG_ENDIAN or
* ByteOrder.LITTLE_ENDIAN, indicating which byte
* order is being used.
*
* @see java.nio.ByteOrder
* @see #setByteOrder
*/
ByteOrder getByteOrder();
/**
* Reads a single byte from the stream and returns it as an
* integer between 0 and 255. If the end of the stream is
* reached, -1 is returned.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a byte value from the stream, as an int, or -1 to
* indicate EOF.
*
* @exception IOException if an I/O error occurs.
*/
int read() throws IOException;
/**
* Reads up to b.length bytes from the stream, and
* stores them into b starting at index 0. The
* number of bytes read is returned. If no bytes can be read
* because the end of the stream has been reached, -1 is returned.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @param b an array of bytes to be written to.
*
* @return the number of bytes actually read, or -1
* to indicate EOF.
*
* @exception NullPointerException if b is
* null.
*
* @exception IOException if an I/O error occurs.
*/
int read(byte[] b) throws IOException;
/**
* Reads up to len bytes from the stream, and stores
* them into b starting at index off.
* The number of bytes read is returned. If no bytes can be read
* because the end of the stream has been reached, -1
* is returned.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @param b an array of bytes to be written to.
* @param off the starting position within b to write to.
* @param len the maximum number of bytes to read.
*
* @return the number of bytes actually read, or -1
* to indicate EOF.
*
* @exception NullPointerException if b is
* null.
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than b.length.
* @exception IOException if an I/O error occurs.
*/
int read(byte[] b, int off, int len) throws IOException;
/**
* 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.
* 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.
*
* @param buf an IIOByteBuffer object to be modified.
* @param len the maximum number of bytes to read.
*
* @exception IndexOutOfBoundsException if len is
* negative.
* @exception NullPointerException if buf is
* null.
*
* @exception IOException if an I/O error occurs.
*/
void readBytes(IIOByteBuffer buf, int len) throws IOException;
/**
* Reads a byte from the stream and returns a boolean
* value of true if it is nonzero, false
* if it is zero.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a boolean value from the stream.
*
* @exception EOFException if the end of the stream is reached.
* @exception IOException if an I/O error occurs.
*/
boolean readBoolean() throws IOException;
/**
* Reads a byte from the stream and returns it as a
* byte value. Byte values between 0x00
* and 0x7f represent integer values between
* 0 and 127. Values between
* 0x80 and 0xff represent negative
* values from -128 to /1.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a signed byte value from the stream.
*
* @exception EOFException if the end of the stream is reached.
* @exception IOException if an I/O error occurs.
*/
byte readByte() throws IOException;
/**
* Reads a byte from the stream, and (conceptually) converts it to
* an int, masks it with 0xff in order to strip off
* any sign-extension bits, and returns it as a byte
* value.
*
*
Thus, byte values between 0x00 and
* 0x7f are simply returned as integer values between
* 0 and 127. Values between
* 0x80 and 0xff, which normally
* represent negative bytevalues, will be mapped into
* positive integers between 128 and
* 255.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return an unsigned byte value from the stream.
*
* @exception EOFException if the end of the stream is reached.
* @exception IOException if an I/O error occurs.
*/
int readUnsignedByte() throws IOException;
/**
* Reads two bytes from the stream, and (conceptually)
* concatenates them according to the current byte order, and
* returns the result as a short value.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a signed short value from the stream.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #getByteOrder
*/
short readShort() throws IOException;
/**
* Reads two bytes from the stream, and (conceptually)
* concatenates them according to the current byte order, converts
* the resulting value to an int, masks it with
* 0xffff in order to strip off any sign-extension
* buts, and returns the result as an unsigned int
* value.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return an unsigned short value from the stream, as an int.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #getByteOrder
*/
int readUnsignedShort() throws IOException;
/**
* Equivalent to readUnsignedShort, except that the
* result is returned using the char datatype.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return an unsigned char value from the stream.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #readUnsignedShort
*/
char readChar() throws IOException;
/**
* Reads 4 bytes from the stream, and (conceptually) concatenates
* them according to the current byte order and returns the result
* as an int.
*
*
The bit offset within the stream is ignored and treated as
* though it were zero.
*
* @return a signed int value from the stream.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #getByteOrder
*/
int readInt() throws IOException;
/**
* 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.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return an unsigned int value from the stream, as a long.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #getByteOrder
*/
long readUnsignedInt() throws IOException;
/**
* Reads 8 bytes from the stream, and (conceptually) concatenates
* them according to the current byte order and returns the result
* as a long.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a signed long value from the stream.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #getByteOrder
*/
long readLong() throws IOException;
/**
* Reads 4 bytes from the stream, and (conceptually) concatenates
* them according to the current byte order and returns the result
* as a float.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a float value from the stream.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #getByteOrder
*/
float readFloat() throws IOException;
/**
* Reads 8 bytes from the stream, and (conceptually) concatenates
* them according to the current byte order and returns the result
* as a double.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a double value from the stream.
*
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*
* @see #getByteOrder
*/
double readDouble() throws IOException;
/**
* Reads the next line of text from the input stream. It reads
* successive bytes, converting each byte separately into a
* character, until it encounters a line terminator or end of
* file; the characters read are then returned as a
* String. 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.
*
*
The bit offset within the stream is reset to zero before
* the read occurs.
*
* @return a String containing a line of text from the stream.
*
* @exception IOException if an I/O error occurs.
*/
String readLine() throws IOException;
/**
* Reads in a string that has been encoded using a
* modified
* UTF-8
* format. The general contract of readUTF 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 the manner of the
* readUnsignedShort method, using network byte order
* (regardless of the current byte order setting). 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 current byte order setting is ignored. * *
The bit offset within the stream is reset to zero before * the read occurs. * *
Note: This method should not be used in
* the implementation of image formats that use standard UTF-8,
* because the modified UTF-8 used here is incompatible with
* standard UTF-8.
*
* @return a String read from the stream.
*
* @exception EOFException if this stream reaches the end
* before reading all the bytes.
* @exception UTFDataFormatException if the bytes do not represent a
* valid modified UTF-8 encoding of a string.
* @exception IOException if an I/O error occurs.
*/
String readUTF() throws IOException;
/**
* Reads len bytes from the stream, and stores them
* into b 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.
*
* @param b an array of bytes to be written to.
* @param off the starting position within b to write to.
* @param len the maximum number of bytes to read.
*
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than b.length.
* @exception NullPointerException if b is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(byte[] b, int off, int len) throws IOException;
/**
* Reads b.length bytes from the stream, and stores them
* into b starting at index 0.
* 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.
*
* @param b an array of bytes.
*
* @exception NullPointerException if b is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(byte[] b) throws IOException;
/**
* 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. 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.
*
* @param s an array of shorts to be written to.
* @param off the starting position withinb to write to.
* @param len the maximum number of shorts to read.
*
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than s.length.
* @exception NullPointerException if s is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(short[] s, int off, int len) throws IOException;
/**
* 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. 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.
*
* @param c an array of chars to be written to.
* @param off the starting position withinb to write to.
* @param len the maximum number of chars to read.
*
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than c.length.
* @exception NullPointerException if c is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(char[] c, int off, int len) throws IOException;
/**
* 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. 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.
*
* @param i an array of ints to be written to.
* @param off the starting position withinb to write to.
* @param len the maximum number of ints to read.
*
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than i.length.
* @exception NullPointerException if i is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(int[] i, int off, int len) throws IOException;
/**
* 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. 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.
*
* @param l an array of longs to be written to.
* @param off the starting position withinb to write to.
* @param len the maximum number of longs to read.
*
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than l.length.
* @exception NullPointerException if l is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(long[] l, int off, int len) throws IOException;
/**
* 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. 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.
*
* @param f an array of floats to be written to.
* @param off the starting position withinb to write to.
* @param len the maximum number of floats to read.
*
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than f.length.
* @exception NullPointerException if f is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(float[] f, int off, int len) throws IOException;
/**
* 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. 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.
*
* @param d an array of doubles to be written to.
* @param off the starting position withinb to write to.
* @param len the maximum number of doubles to read.
*
* @exception IndexOutOfBoundsException if off is
* negative, len is negative, or off +
* len is greater than d.length.
* @exception NullPointerException if d is
* null.
* @exception EOFException if the stream reaches the end before
* reading all the bytes.
* @exception IOException if an I/O error occurs.
*/
void readFully(double[] d, int off, int len) throws IOException;
/**
* Returns the current byte position of the stream. The next read
* will take place starting at this offset.
*
* @return a long containing the position of the stream.
*
* @exception IOException if an I/O error occurs.
*/
long getStreamPosition() throws IOException;
/**
* Returns the current bit offset, as an integer between 0 and 7,
* inclusive. The bit offset is updated implicitly by calls to
* the readBits 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.
*
* @return an int containing the bit offset between
* 0 and 7, inclusive.
*
* @exception IOException if an I/O error occurs.
*
* @see #setBitOffset
*/
int getBitOffset() throws IOException;
/**
* Sets the bit offset to an integer between 0 and 7, inclusive.
* The byte offset within the stream, as returned by
* getStreamPosition, 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.
*
* @param bitOffset the desired offset, as an int
* between 0 and 7, inclusive.
*
* @exception IllegalArgumentException if bitOffset
* is not between 0 and 7, inclusive.
* @exception IOException if an I/O error occurs.
*
* @see #getBitOffset
*/
void setBitOffset(int bitOffset) throws IOException;
/**
* Reads a single bit from the stream and returns it as an
* int with the value 0 or
* 1. The bit offset is advanced by one and reduced
* modulo 8.
*
* @return an int containing the value 0
* or 1.
*
* @exception EOFException if the stream reaches the end before
* reading all the bits.
* @exception IOException if an I/O error occurs.
*/
int readBit() throws IOException;
/**
* 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. 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.
*
* @param numBits the number of bits to read, as an int
* between 0 and 64, inclusive.
* @return the bitstring, as a long with the last bit
* read stored in the least significant bit.
*
* @exception IllegalArgumentException if numBits
* is not between 0 and 64, inclusive.
* @exception EOFException if the stream reaches the end before
* reading all the bits.
* @exception IOException if an I/O error occurs.
*/
long readBits(int numBits) throws IOException;
/**
* Returns the total length of the stream, if known. Otherwise,
* -1 is returned.
*
* @return a long containing the length of the
* stream, if known, or else -1.
*
* @exception IOException if an I/O error occurs.
*/
long length() throws IOException;
/**
* Moves the stream position forward by a given number of bytes. It
* is possible that this method will only be able to skip forward
* by a smaller number of bytes than requested, for example if the
* end of the stream is reached. In all cases, the actual number
* of bytes skipped is returned. The bit offset is set to zero
* prior to advancing the position.
*
* @param n an int containing the number of bytes to
* be skipped.
*
* @return an int representing the number of bytes skipped.
*
* @exception IOException if an I/O error occurs.
*/
int skipBytes(int n) throws IOException;
/**
* Moves the stream position forward by a given number of bytes.
* This method is identical to skipBytes(int) except
* that it allows for a larger skip distance.
*
* @param n a long containing the number of bytes to
* be skipped.
*
* @return a long representing the number of bytes
* skipped.
*
* @exception IOException if an I/O error occurs.
*/
long skipBytes(long n) throws IOException;
/**
* Sets the current stream position to the desired location. The
* next read will occur at this location. The bit offset is set
* to 0.
*
*
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.
*
* @param pos a long containing the desired file
* pointer position.
*
* @exception IndexOutOfBoundsException if pos is smaller
* than the flushed position.
* @exception IOException if any other I/O error occurs.
*/
void seek(long pos) throws IOException;
/**
* Marks a position in the stream to be returned to by a
* subsequent call to reset. Unlike a standard
* InputStream, all ImageInputStreams
* support marking. Additionally, calls to mark and
* reset may be nested arbitrarily.
*
*
Unlike the mark methods declared by the
* Reader and InputStream interfaces, no
* readLimit parameter is used. An arbitrary amount
* of data may be read following the call to mark.
*
*
The bit position used by the readBits method
* is saved and restored by each pair of calls to
* mark and reset.
*
*
Note that it is valid for an ImageReader to call
* flushBefore as part of a read operation.
* Therefore, if an application calls mark prior to
* passing that stream to an ImageReader, the application
* should not assume that the marked position will remain valid after
* the read operation has completed.
*/
void mark();
/**
* Returns the stream pointer to its previous position, including
* the bit offset, at the time of the most recent unmatched call
* to mark.
*
*
Calls to reset without a corresponding call
* to mark have no effect.
*
*
An IOException will be thrown if the previous
* marked position lies in the discarded portion of the stream.
*
* @exception IOException if an I/O error occurs.
*/
void reset() throws IOException;
/**
* Discards the initial portion of the stream prior to the
* indicated postion. Attempting to seek to an offset within the
* flushed portion of the stream will result in an
* IndexOutOfBoundsException.
*
*
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.
*
* @param pos a long containing the length of the
* stream prefix that may be flushed.
*
* @exception IndexOutOfBoundsException if pos lies
* in the flushed portion of the stream or past the current stream
* position.
* @exception IOException if an I/O error occurs.
*/
void flushBefore(long pos) throws IOException;
/**
* Discards the initial position of the stream prior to the current
* stream position. Equivalent to
* flushBefore(getStreamPosition()).
*
* @exception IOException if an I/O error occurs.
*/
void flush() throws IOException;
/**
* Returns the earliest position in the stream to which seeking
* may be performed. The returned value will be the maximum of
* all values passed into previous calls to
* flushBefore.
*
* @return the earliest legal position for seeking, as a
* long.
*/
long getFlushedPosition();
/**
* Returns true if this ImageInputStream
* caches data itself in order to allow seeking backwards.
* Applications may consult this in order to decide how frequently,
* or whether, to flush in order to conserve cache resources.
*
* @return true if this ImageInputStream
* caches data.
*
* @see #isCachedMemory
* @see #isCachedFile
*/
boolean isCached();
/**
* Returns true if this ImageInputStream
* caches data itself in order to allow seeking backwards, and
* the cache is kept in main memory. Applications may consult
* this in order to decide how frequently, or whether, to flush
* in order to conserve cache resources.
*
* @return true if this ImageInputStream
* caches data in main memory.
*
* @see #isCached
* @see #isCachedFile
*/
boolean isCachedMemory();
/**
* Returns true if this ImageInputStream
* caches data itself in order to allow seeking backwards, and
* the cache is kept in a temporary file. Applications may consult
* this in order to decide how frequently, or whether, to flush
* in order to conserve cache resources.
*
* @return true if this ImageInputStream
* caches data in a temporary file.
*
* @see #isCached
* @see #isCachedMemory
*/
boolean isCachedFile();
/**
* Closes the stream. Attempts to access a stream that has been
* closed may result in IOExceptions 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.
*
* @exception IOException if an I/O error occurs.
*/
void close() throws IOException;
}