Interface ImageOutputStream

All Superinterfaces:

AutoCloseable, Closeable, DataInput, DataOutput, ImageInputStream

All Known Implementing Classes:

FileCacheImageOutputStream, FileImageOutputStream, ImageOutputStreamImpl, MemoryCacheImageOutputStream

public interface ImageOutputStream
extends ImageInputStream, DataOutput

A seekable output stream interface for use by ImageWriters. Various output destinations, such as OutputStreams and Files, as well as future fast I/O destinations may be "wrapped" by a suitable implementation of this interface for use by the Image I/O API.

Unlike a standard OutputStream, ImageOutputStream extends its counterpart, ImageInputStream. Thus it is possible to read from the stream as it is being written. The same seek and flush positions apply to both reading and writing, although the semantics for dealing with a non-zero bit offset before a byte-aligned write are necessarily different from the semantics for dealing with a non-zero bit offset before a byte-aligned read. When reading bytes, any bit offset is set to 0 before the read; when writing bytes, a non-zero bit offset causes the remaining bits in the byte to be written as 0s. The byte-aligned write then starts at the next byte position.

See Also:

• ImageInputStream

Method Summary

Modifier and Type	Method	Description
void	flushBefore(long pos)	Flushes all data prior to the given position to the underlying destination, such as an OutputStream or File.
void	write(byte[] b)	Writes a sequence of bytes to the stream at the current position.
void	write(byte[] b, int off, int len)	Writes a sequence of bytes to the stream at the current position.
void	write(int b)	Writes a single byte to the stream at the current position.
void	writeBit(int bit)	Writes a single bit, given by the least significant bit of the argument, to the stream at the current bit offset within the current byte position.
void	writeBits(long bits, int numBits)	Writes a sequence of bits, given by the numBits least significant bits of the bits argument in left-to-right order, to the stream at the current bit offset within the current byte position.
void	writeBoolean(boolean v)	Writes a boolean value to the stream.
void	writeByte(int v)	Writes the 8 low-order bits of v to the stream.
void	writeBytes(String s)	Writes a string to the output stream.
void	writeChar(int v)	This method is a synonym for writeShort.
void	writeChars(char[] c, int off, int len)	Writes a sequence of chars to the stream at the current position.
void	writeChars(String s)	Writes a string to the output stream.
void	writeDouble(double v)	Writes a double value, which is comprised of four bytes, to the output stream.
void	writeDoubles(double[] d, int off, int len)	Writes a sequence of doubles to the stream at the current position.
void	writeFloat(float v)	Writes a float value, which is comprised of four bytes, to the output stream.
void	writeFloats(float[] f, int off, int len)	Writes a sequence of floats to the stream at the current position.
void	writeInt(int v)	Writes the 32 bits of v to the stream.
void	writeInts(int[] i, int off, int len)	Writes a sequence of ints to the stream at the current position.
void	writeLong(long v)	Writes the 64 bits of v to the stream.
void	writeLongs(long[] l, int off, int len)	Writes a sequence of longs to the stream at the current position.
void	writeShort(int v)	Writes the 16 low-order bits of v to the stream.
void	writeShorts(short[] s, int off, int len)	Writes a sequence of shorts to the stream at the current position.
void	writeUTF(String s)	Writes two bytes of length information to the output stream in network byte order, followed by the modified UTF-8 representation of every character in the string s.

Methods declared in interface ImageInputStream

close, flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, length, mark, read, read, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Modifier and Type	Method	Description
void	close()	Closes the stream.
void	flush()	Discards the initial position of the stream prior to the current stream position.
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()	Returns true if this ImageInputStream caches data itself in order to allow seeking backwards.
boolean	isCachedFile()	Returns true if this ImageInputStream caches data itself in order to allow seeking backwards, and the cache is kept in a temporary file.
boolean	isCachedMemory()	Returns true if this ImageInputStream caches data itself in order to allow seeking backwards, and the cache is kept in main memory.
long	length()	Returns the total length of the stream, if known.
void	mark()	Marks a position in the stream to be returned to by a subsequent call to reset.
int	read()	Reads a single byte from the stream and returns it as an integer between 0 and 255.
int	read(byte[] b)	Reads up to b.length bytes from the stream, and stores them into b starting at index 0.
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 a byte from the stream and returns a boolean value of true if it is nonzero, false if it is zero.
byte	readByte()	Reads a byte from the stream and returns it as a byte value.
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()	Equivalent to readUnsignedShort, except that the result is returned using the char datatype.
double	readDouble()	Reads 8 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as a double.
float	readFloat()	Reads 4 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as a float.
void	readFully(byte[] b)	Reads b.length bytes from the stream, and stores them into b starting at index 0.
void	readFully(byte[] b, int off, int len)	Reads len bytes from the stream, and stores them into b starting at index off.
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 4 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as an int.
String	readLine()	Reads the next line of text from the input stream.
long	readLong()	Reads 8 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as a long.
short	readShort()	Reads two bytes from the stream, and (conceptually) concatenates them according to the current byte order, and returns the result as a short value.
int	readUnsignedByte()	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.
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 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.
String	readUTF()	Reads in a string that has been encoded using a modified UTF-8 format.
void	reset()	Returns the stream pointer to its previous position, including the bit offset, at the time of the most recent unmatched call to mark.
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)	Moves the stream position forward by a given number of bytes.
long	skipBytes(long n)	Moves the stream position forward by a given number of bytes.

Method Details

write

void write(int b)
    throws IOException

Writes a single byte to the stream at the current position. The 24 high-order bits of b are ignored.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write. Implementers can use the flushBits method of ImageOutputStreamImpl to guarantee this.

Specified by:

write in interface DataOutput

Parameters:

b - an int whose lower 8 bits are to be written.

Throws:

IOException - if an I/O error occurs.

write

void write(byte[] b)
    throws IOException

Writes a sequence of bytes to the stream at the current position. If b.length is 0, nothing is written. The byte b[0] is written first, then the byte b[1], and so on.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

write in interface DataOutput

Parameters:

b - an array of bytes to be written.

Throws:

NullPointerException - if b is null.

IOException - if an I/O error occurs.

write

void write(byte[] b,
 int off,
 int len)
    throws IOException

Writes a sequence of bytes to the stream at the current position. If len is 0, nothing is written. The byte b[off] is written first, then the byte b[off + 1], and so on.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write. Implementers can use the flushBits method of ImageOutputStreamImpl to guarantee this.

Specified by:

write in interface DataOutput

Parameters:

b - an array of bytes to be written.

off - the start offset in the data.

len - the number of bytes to write.

Throws:

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.

writeBoolean

void writeBoolean(boolean v)
           throws IOException

Writes a boolean value to the stream. If v is true, the value (byte)1 is written; if v is false, the value (byte)0 is written.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeBoolean in interface DataOutput

Parameters:

v - the boolean to be written.

Throws:

IOException - if an I/O error occurs.

writeByte

void writeByte(int v)
        throws IOException

Writes the 8 low-order bits of v to the stream. The 24 high-order bits of v are ignored. (This means that writeByte does exactly the same thing as write for an integer argument.)

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeByte in interface DataOutput

Parameters:

v - an int containing the byte value to be written.

Throws:

IOException - if an I/O error occurs.

writeShort

void writeShort(int v)
         throws IOException

Writes the 16 low-order bits of v to the stream. The 16 high-order bits of v are ignored. If the stream uses network byte order, the bytes written, in order, will be:

(byte)((v >> 8) & 0xff)
(byte)(v & 0xff)

Otherwise, the bytes written will be:

(byte)(v & 0xff)
(byte)((v >> 8) & 0xff)

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeShort in interface DataOutput

Parameters:

v - an int containing the short value to be written.

Throws:

IOException - if an I/O error occurs.

writeChar

void writeChar(int v)
        throws IOException

This method is a synonym for writeShort.

Specified by:

writeChar in interface DataOutput

Parameters:

v - an int containing the char (unsigned short) value to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

• writeShort(int)

writeInt

void writeInt(int v)
       throws IOException

Writes the 32 bits of v to the stream. If the stream uses network byte order, the bytes written, in order, will be:

(byte)((v >> 24) & 0xff)
(byte)((v >> 16) & 0xff)
(byte)((v >> 8) & 0xff)
(byte)(v & 0xff)

Otherwise, the bytes written will be:

(byte)(v & 0xff)
(byte)((v >> 8) & 0xff)
(byte)((v >> 16) & 0xff)
(byte)((v >> 24) & 0xff)

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeInt in interface DataOutput

Parameters:

v - an int containing the value to be written.

Throws:

IOException - if an I/O error occurs.

writeLong

void writeLong(long v)
        throws IOException

Writes the 64 bits of v to the stream. If the stream uses network byte order, the bytes written, in order, will be:

(byte)((v >> 56) & 0xff)
(byte)((v >> 48) & 0xff)
(byte)((v >> 40) & 0xff)
(byte)((v >> 32) & 0xff)
(byte)((v >> 24) & 0xff)
(byte)((v >> 16) & 0xff)
(byte)((v >> 8) & 0xff)
(byte)(v & 0xff)

Otherwise, the bytes written will be:

(byte)(v & 0xff)
(byte)((v >> 8) & 0xff)
(byte)((v >> 16) & 0xff)
(byte)((v >> 24) & 0xff)
(byte)((v >> 32) & 0xff)
(byte)((v >> 40) & 0xff)
(byte)((v >> 48) & 0xff)
(byte)((v >> 56) & 0xff)

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeLong in interface DataOutput

Parameters:

v - a long containing the value to be written.

Throws:

IOException - if an I/O error occurs.

writeFloat

void writeFloat(float v)
         throws IOException

Writes a float value, which is comprised of four bytes, to the output stream. It does this as if it first converts this float value to an int in exactly the manner of the Float.floatToIntBits method and then writes the int value in exactly the manner of the writeInt method.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeFloat in interface DataOutput

Parameters:

v - a float containing the value to be written.

Throws:

IOException - if an I/O error occurs.

writeDouble

void writeDouble(double v)
          throws IOException

Writes a double value, which is comprised of four bytes, to the output stream. It does this as if it first converts this double value to a long in exactly the manner of the Double.doubleToLongBits method and then writes the long value in exactly the manner of the writeLong method.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeDouble in interface DataOutput

Parameters:

v - a double containing the value to be written.

Throws:

IOException - if an I/O error occurs.

writeBytes

void writeBytes(String s)
         throws IOException

Writes a string to the output stream. For every character in the string s, taken in order, one byte is written to the output stream. If s is null, a NullPointerException is thrown.

If s.length is zero, then no bytes are written. Otherwise, the character s[0] is written first, then s[1], and so on; the last character written is s[s.length-1]. For each character, one byte is written, the low-order byte, in exactly the manner of the writeByte method. The high-order eight bits of each character in the string are ignored.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeBytes in interface DataOutput

Parameters:

s - a String containing the value to be written.

Throws:

NullPointerException - if s is null.

IOException - if an I/O error occurs.

writeChars

void writeChars(String s)
         throws IOException

Writes a string to the output stream. For every character in the string s, taken in order, two bytes are written to the output stream, ordered according to the current byte order setting. If network byte order is being used, the high-order byte is written first; the order is reversed otherwise. If s is null, a NullPointerException is thrown.

If s.length is zero, then no bytes are written. Otherwise, the character s[0] is written first, then s[1], and so on; the last character written is s[s.length-1].

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Specified by:

writeChars in interface DataOutput

Parameters:

s - a String containing the value to be written.

Throws:

NullPointerException - if s is null.

IOException - if an I/O error occurs.

writeUTF

void writeUTF(String s)
       throws IOException

Writes two bytes of length information to the output stream in network byte order, followed by the modified UTF-8 representation of every character in the string s. If s is null, a NullPointerException is thrown. Each character in the string s is converted to a group of one, two, or three bytes, depending on the value of the character.

If a character c is in the range \u0001 through \u007f, it is represented by one byte:

(byte)c

If a character c is \u0000 or is in the range \u0080 through \u07ff, then it is represented by two bytes, to be written in the order shown:

(byte)(0xc0 | (0x1f & (c >> 6)))
(byte)(0x80 | (0x3f & c))

If a character c is in the range \u0800 through uffff, then it is represented by three bytes, to be written in the order shown:

(byte)(0xe0 | (0x0f & (c >> 12)))
(byte)(0x80 | (0x3f & (c >> 6)))
(byte)(0x80 | (0x3f & c))

First, the total number of bytes needed to represent all the characters of s is calculated. If this number is larger than 65535, then a UTFDataFormatException is thrown. Otherwise, this length is written to the output stream in exactly the manner of the writeShort method; after this, the one-, two-, or three-byte representation of each character in the string s is written.

The current byte order setting is ignored.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

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.

Specified by:

writeUTF in interface DataOutput

Parameters:

s - a String containing the value to be written.

Throws:

NullPointerException - if s is null.

UTFDataFormatException - if the modified UTF-8 representation of s requires more than 65536 bytes.

IOException - if an I/O error occurs.

writeShorts

void writeShorts(short[] s,
 int off,
 int len)
          throws IOException

Writes a sequence of shorts to the stream at the current position. If len is 0, nothing is written. The short s[off] is written first, then the short s[off + 1], and so on. The byte order of the stream is used to determine the order in which the individual bytes are written.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Parameters:

s - an array of shorts to be written.

off - the start offset in the data.

len - the number of shorts to write.

Throws:

IndexOutOfBoundsException - if off is negative, len is negative, or off + len is greater than s.length.

NullPointerException - if s is null.

IOException - if an I/O error occurs.

writeChars

void writeChars(char[] c,
 int off,
 int len)
         throws IOException

Writes a sequence of chars to the stream at the current position. If len is 0, nothing is written. The char c[off] is written first, then the char c[off + 1], and so on. The byte order of the stream is used to determine the order in which the individual bytes are written.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Parameters:

c - an array of chars to be written.

off - the start offset in the data.

len - the number of chars to write.

Throws:

IndexOutOfBoundsException - if off is negative, len is negative, or off + len is greater than c.length.

NullPointerException - if c is null.

IOException - if an I/O error occurs.

writeInts

void writeInts(int[] i,
 int off,
 int len)
        throws IOException

Writes a sequence of ints to the stream at the current position. If len is 0, nothing is written. The int i[off] is written first, then the int i[off + 1], and so on. The byte order of the stream is used to determine the order in which the individual bytes are written.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Parameters:

i - an array of ints to be written.

off - the start offset in the data.

len - the number of ints to write.

Throws:

IndexOutOfBoundsException - if off is negative, len is negative, or off + len is greater than i.length.

NullPointerException - if i is null.

IOException - if an I/O error occurs.

writeLongs

void writeLongs(long[] l,
 int off,
 int len)
         throws IOException

Writes a sequence of longs to the stream at the current position. If len is 0, nothing is written. The long l[off] is written first, then the long l[off + 1], and so on. The byte order of the stream is used to determine the order in which the individual bytes are written.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Parameters:

l - an array of longs to be written.

off - the start offset in the data.

len - the number of longs to write.

Throws:

IndexOutOfBoundsException - if off is negative, len is negative, or off + len is greater than l.length.

NullPointerException - if l is null.

IOException - if an I/O error occurs.

writeFloats

void writeFloats(float[] f,
 int off,
 int len)
          throws IOException

Writes a sequence of floats to the stream at the current position. If len is 0, nothing is written. The float f[off] is written first, then the float f[off + 1], and so on. The byte order of the stream is used to determine the order in which the individual bytes are written.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Parameters:

f - an array of floats to be written.

off - the start offset in the data.

len - the number of floats to write.

Throws:

IndexOutOfBoundsException - if off is negative, len is negative, or off + len is greater than f.length.

NullPointerException - if f is null.

IOException - if an I/O error occurs.

writeDoubles

void writeDoubles(double[] d,
 int off,
 int len)
           throws IOException

Writes a sequence of doubles to the stream at the current position. If len is 0, nothing is written. The double d[off] is written first, then the double d[off + 1], and so on. The byte order of the stream is used to determine the order in which the individual bytes are written.

If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write.

Parameters:

d - an array of doubless to be written.

off - the start offset in the data.

len - the number of doubles to write.

Throws:

IndexOutOfBoundsException - if off is negative, len is negative, or off + len is greater than d.length.

NullPointerException - if d is null.

IOException - if an I/O error occurs.

writeBit

void writeBit(int bit)
       throws IOException

Writes a single bit, given by the least significant bit of the argument, to the stream at the current bit offset within the current byte position. The upper 31 bits of the argument are ignored. The given bit replaces the previous bit at that position. The bit offset is advanced by one and reduced modulo 8.

If any bits of a particular byte have never been set at the time the byte is flushed to the destination, those bits will be set to 0 automatically.

Parameters:

bit - an int whose least significant bit is to be written to the stream.

Throws:

IOException - if an I/O error occurs.

writeBits

void writeBits(long bits,
 int numBits)
        throws IOException

Writes a sequence of bits, given by the numBits least significant bits of the bits argument in left-to-right order, to the stream at the current bit offset within the current byte position. The upper 64 - numBits bits of the argument are ignored. The bit offset is advanced by numBits and reduced modulo 8. Note that a bit offset of 0 always indicates the most-significant bit of the byte, and bytes of bits are written out in sequence as they are encountered. Thus bit writes are always effectively in network byte order. The actual stream byte order setting is ignored.

Bit data may be accumulated in memory indefinitely, until flushBefore is called. At that time, all bit data prior to the flushed position will be written.

If any bits of a particular byte have never been set at the time the byte is flushed to the destination, those bits will be set to 0 automatically.

Parameters:

bits - a long containing the bits to be written, starting with the bit in position numBits - 1 down to the least significant bit.

numBits - an int between 0 and 64, inclusive.

Throws:

IllegalArgumentException - if numBits is not between 0 and 64, inclusive.

IOException - if an I/O error occurs.

flushBefore

void flushBefore(long pos)
          throws IOException

Flushes all data prior to the given position to the underlying destination, such as an OutputStream or File. Attempting to seek to the flushed portion of the stream will result in an IndexOutOfBoundsException.

Specified by:

flushBefore in interface ImageInputStream

Parameters:

pos - a long containing the length of the stream prefix that may be flushed to the destination.

Throws:

IndexOutOfBoundsException - if pos lies in the flushed portion of the stream or past the current stream position.

IOException - if an I/O error occurs.