OpenJDK 27 · javax.imageio.stream.ImageInputStream · APIdia, the JavaDoc alternative

Method Summary

Modifier and Type	Method and Description
public void	close() Redeclares java.io.Closeable.close. Closes the stream.
public void	flush() Discards the initial position of the stream prior to the current stream position.
public void	flushBefore(long a `long` containing the length of the stream prefix that may be flushed. pos) Discards the initial portion of the stream prior to the indicated position.
public int	Returns: an `int` containing the bit offset between 0 and 7, inclusive. getBitOffset() Returns the current bit offset, as an integer between 0 and 7, inclusive.
public ByteOrder	Returns: one of `ByteOrder.BIG_ENDIAN` or `ByteOrder.LITTLE_ENDIAN`, indicating which byte order is being used. getByteOrder() Returns the byte order with which data values will be read from this stream as an instance of the `java.nio.ByteOrder` enumeration.
public long	Returns: the earliest legal position for seeking, as a `long`. getFlushedPosition() Returns the earliest position in the stream to which seeking may be performed.
public long	Returns: a long containing the position of the stream. getStreamPosition() Returns the current byte position of the stream.
public boolean	Returns: `true` if this `ImageInputStream` caches data. isCached() Returns `true` if this `ImageInputStream` caches data itself in order to allow seeking backwards.
public boolean	Returns: `true` if this `ImageInputStream` caches data in a temporary file. isCachedFile() Returns `true` if this `ImageInputStream` caches data itself in order to allow seeking backwards, and the cache is kept in a temporary file.
public boolean	Returns: `true` if this `ImageInputStream` caches data in main memory. isCachedMemory() Returns `true` if this `ImageInputStream` caches data itself in order to allow seeking backwards, and the cache is kept in main memory.
public long	Returns: a `long` containing the length of the stream, if known, or else `-1`. length() Returns the total length of the stream, if known.
public void	mark() Marks a position in the stream to be returned to by a subsequent call to `reset`.
public int	Returns: a byte value from the stream, as an int, or -1 to indicate EOF. read() Reads a single byte from the stream and returns it as an integer between 0 and 255.
public int	Returns: the number of bytes actually read, or `-1` to indicate EOF. read(byte[] an array of bytes to be written to. b) Reads up to `b.length` bytes from the stream, and stores them into `b` starting at index 0.
public int	Returns: the number of bytes actually read, or `-1` to indicate EOF. read(byte[] an array of bytes to be written to. b, int the starting position within `b` to write to. off, int the maximum number of `byte`s to read. len) Reads up to `len` bytes from the stream, and stores them into `b` starting at index `off`.
public int	Returns: an `int` containing the value `0` or `1`. readBit() Reads a single bit from the stream and returns it as an `int` with the value `0` or `1`.
public long	Returns: the bitstring, as a `long` with the last bit read stored in the least significant bit. readBits(int the number of bits to read, as an `int` between 0 and 64, inclusive. 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.
public boolean	Returns: a boolean value from the stream. readBoolean() Redeclares java.io.DataInput.readBoolean. Reads a byte from the stream and returns a `boolean` value of `true` if it is nonzero, `false` if it is zero.
public byte	Returns: a signed byte value from the stream. readByte() Redeclares java.io.DataInput.readByte. Reads a byte from the stream and returns it as a `byte` value.
public void	readBytes(IIOByteBuffer an IIOByteBuffer object to be modified. buf, int the maximum number of `byte`s to read. 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.
public char	Returns: an unsigned char value from the stream. readChar() Redeclares java.io.DataInput.readChar. Equivalent to `readUnsignedShort`, except that the result is returned using the `char` datatype.
public double	Returns: a double value from the stream. readDouble() Redeclares java.io.DataInput.readDouble. Reads 8 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as a `double`.
public float	Returns: a float value from the stream. readFloat() Redeclares java.io.DataInput.readFloat. Reads 4 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as a `float`.
public void	readFully(byte[] an array of bytes to be written to. b, int the starting position within `b` to write to. off, int the maximum number of `byte`s to read. len) Redeclares java.io.DataInput.readFully. Reads `len` bytes from the stream, and stores them into `b` starting at index `off`.
public void	readFully(byte[] an array of `byte`s. b) Redeclares java.io.DataInput.readFully. Reads `b.length` bytes from the stream, and stores them into `b` starting at index `0`.
public void	readFully(short[] an array of shorts to be written to. s, int the starting position within `s` to write to. off, int the maximum number of `short`s to read. 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`.
public void	readFully(char[] an array of chars to be written to. c, int the starting position within `c` to write to. off, int the maximum number of `char`s to read. 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`.
public void	readFully(int[] an array of ints to be written to. i, int the starting position within `i` to write to. off, int the maximum number of `int`s to read. 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`.
public void	readFully(long[] an array of longs to be written to. l, int the starting position within `l` to write to. off, int the maximum number of `long`s to read. 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`.
public void	readFully(float[] an array of floats to be written to. f, int the starting position within `f` to write to. off, int the maximum number of `float`s to read. 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`.
public void	readFully(double[] an array of doubles to be written to. d, int the starting position within `d` to write to. off, int the maximum number of `double`s to read. 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`.
public int	Returns: a signed int value from the stream. readInt() Redeclares java.io.DataInput.readInt. Reads 4 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as an `int`.
public String	Returns: a String containing a line of text from the stream. readLine() Redeclares java.io.DataInput.readLine. Reads the next line of text from the input stream.
public long	Returns: a signed long value from the stream. readLong() Redeclares java.io.DataInput.readLong. Reads 8 bytes from the stream, and (conceptually) concatenates them according to the current byte order and returns the result as a `long`.
public short	Returns: a signed short value from the stream. readShort() Redeclares java.io.DataInput.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.
public int	Returns: an unsigned byte value from the stream. readUnsignedByte() Redeclares java.io.DataInput.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.
public long	Returns: an unsigned int value from the stream, as a 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.
public int	Returns: an unsigned short value from the stream, as an int. readUnsignedShort() Redeclares java.io.DataInput.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.
public String	Returns: a String read from the stream. readUTF() Redeclares java.io.DataInput.readUTF. Reads in a string that has been encoded using a modified UTF-8 format.
public 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`.
public void	seek(long a `long` containing the desired file pointer position. pos) Sets the current stream position to the desired location.
public void	setBitOffset(int the desired offset, as an `int` between 0 and 7, inclusive. bitOffset) Sets the bit offset to an integer between 0 and 7, inclusive.
public void	setByteOrder(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. byteOrder) Sets the desired byte order for future reads of data values from this stream.
public int	Returns: an `int` representing the number of bytes skipped. skipBytes(int an `int` containing the number of bytes to be skipped. n) Redeclares java.io.DataInput.skipBytes. Moves the stream position forward by a given number of bytes.
public long	Returns: a `long` representing the number of bytes skipped. skipBytes(long a `long` containing the number of bytes to be skipped. n) Moves the stream position forward by a given number of bytes.

Method Detail

close back to summary

close	back to summary
public void close() throws IOException Redeclares java.io.Closeable.close. Closes the stream. Attempts to access a stream that has been closed may result in `IOException`s 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. Exceptions IOException: if an I/O error occurs.

public void close() throws IOException

Redeclares java.io.Closeable.close.

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.

Exceptions

IOException:: if an I/O error occurs.

flush back to summary

flush	back to summary
public void flush() throws IOException Discards the initial position of the stream prior to the current stream position. Equivalent to `flushBefore(getStreamPosition())`. Exceptions IOException: if an I/O error occurs.

public void flush() throws IOException

Discards the initial position of the stream prior to the current stream position. Equivalent to flushBefore(getStreamPosition()).

Exceptions

IOException:: if an I/O error occurs.

flushBefore back to summary

flushBefore	back to summary
public void flushBefore(long pos) throws IOException Discards the initial portion of the stream prior to the indicated position. 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. Parameters pos:long a `long` containing the length of the stream prefix that may be flushed. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `pos` lies in the flushed portion of the stream or past the current stream position.

public void flushBefore(long pos) throws IOException

Discards the initial portion of the stream prior to the indicated position. 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.

Parameters

pos:long: a long containing the length of the stream prefix that may be flushed.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if pos lies in the flushed portion of the stream or past the current stream position.

getBitOffset back to summary

getBitOffset	back to summary
public int getBitOffset() 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. Returns:int an `int` containing the bit offset between 0 and 7, inclusive. Exceptions IOException: if an I/O error occurs. See Also `setBitOffset`

public int getBitOffset() 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.

Returns:int

an int containing the bit offset between 0 and 7, inclusive.

Exceptions

IOException:: if an I/O error occurs.

See Also

setBitOffset

getByteOrder back to summary

getByteOrder	back to summary
public 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. Returns:ByteOrder one of `ByteOrder.BIG_ENDIAN` or `ByteOrder.LITTLE_ENDIAN`, indicating which byte order is being used. See Also `java.nio.ByteOrder`, `setByteOrder`

public 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.

Returns:ByteOrder: one of ByteOrder.BIG_ENDIAN or ByteOrder.LITTLE_ENDIAN, indicating which byte order is being used.
See Also: java.nio.ByteOrder, setByteOrder

getFlushedPosition back to summary

getFlushedPosition	back to summary
public long getFlushedPosition() 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`. Returns:long the earliest legal position for seeking, as a `long`.

public long getFlushedPosition()

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.

Returns:long: the earliest legal position for seeking, as a long.

getStreamPosition	back to summary
public long getStreamPosition() throws IOException Returns the current byte position of the stream. The next read will take place starting at this offset. Returns:long a long containing the position of the stream. Exceptions IOException: if an I/O error occurs.

getStreamPosition

back to summary

public long getStreamPosition() throws IOException

Returns the current byte position of the stream. The next read will take place starting at this offset.

Returns:long

a long containing the position of the stream.

Exceptions

IOException:: if an I/O error occurs.

isCached back to summary

isCached	back to summary
public boolean isCached() 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. Returns:boolean `true` if this `ImageInputStream` caches data. See Also `isCachedMemory`, `isCachedFile`

public boolean isCached()

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.

Returns:boolean: true if this ImageInputStream caches data.
See Also: isCachedMemory, isCachedFile

isCachedFile back to summary

isCachedFile	back to summary
public 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. Applications may consult this in order to decide how frequently, or whether, to flush in order to conserve cache resources. Returns:boolean `true` if this `ImageInputStream` caches data in a temporary file. See Also `isCached`, `isCachedMemory`

public 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. Applications may consult this in order to decide how frequently, or whether, to flush in order to conserve cache resources.

Returns:boolean: true if this ImageInputStream caches data in a temporary file.
See Also: isCached, isCachedMemory

isCachedMemory back to summary

isCachedMemory	back to summary
public boolean isCachedMemory() 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. Returns:boolean `true` if this `ImageInputStream` caches data in main memory. See Also `isCached`, `isCachedFile`

public boolean isCachedMemory()

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.

Returns:boolean: true if this ImageInputStream caches data in main memory.
See Also: isCached, isCachedFile

length back to summary

length	back to summary
public long length() throws IOException Returns the total length of the stream, if known. Otherwise, `-1` is returned. Returns:long a `long` containing the length of the stream, if known, or else `-1`. Exceptions IOException: if an I/O error occurs.

public long length() throws IOException

Returns the total length of the stream, if known. Otherwise, -1 is returned.

Returns:long

a long containing the length of the stream, if known, or else -1.

Exceptions

IOException:: if an I/O error occurs.

mark back to summary

mark	back to summary
public void mark() Marks a position in the stream to be returned to by a subsequent call to `reset`. Unlike a standard `InputStream`, all `ImageInputStream`s 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.

public void mark()

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.

read	back to summary
public int read() throws IOException 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. Returns:int a byte value from the stream, as an int, or -1 to indicate EOF. Exceptions IOException: if an I/O error occurs.

read

back to summary

public int read() throws IOException

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.

Returns:int

a byte value from the stream, as an int, or -1 to indicate EOF.

Exceptions

IOException:: if an I/O error occurs.

read back to summary

read	back to summary
public int read(byte[] b) 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. Parameters b:byte[] an array of bytes to be written to. Returns:int the number of bytes actually read, or `-1` to indicate EOF. Exceptions IOException: if an I/O error occurs. NullPointerException: if `b` is `null`.

public int read(byte[] b) 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.

Parameters

b:byte[]: an array of bytes to be written to.

Returns:int

the number of bytes actually read, or -1 to indicate EOF.

Exceptions

IOException:: if an I/O error occurs.
NullPointerException:: if b is null.

read back to summary

read	back to summary
public int read(byte[] b, int off, int len) 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. Parameters b:byte[] an array of bytes to be written to. off:int the starting position within `b` to write to. len:int the maximum number of `byte`s to read. Returns:int the number of bytes actually read, or `-1` to indicate EOF. Exceptions IOException: if an I/O error occurs. NullPointerException: if `b` is `null`. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `b.length`.

public int read(byte[] b, int off, int len) 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.

Parameters

b:byte[]: an array of bytes to be written to.
off:int: the starting position within b to write to.
len:int: the maximum number of bytes to read.

Returns:int

the number of bytes actually read, or -1 to indicate EOF.

Exceptions

IOException:: if an I/O error occurs.
NullPointerException:: if b is null.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than b.length.

readBit back to summary

readBit	back to summary
public int readBit() 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. Returns:int an `int` containing the value `0` or `1`. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bits.

public int readBit() 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.

Returns:int

an int containing the value 0 or 1.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bits.

readBits back to summary

readBits	back to summary
public long readBits(int numBits) 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, a `java.io.EOFException` is thrown. Parameters numBits:int the number of bits to read, as an `int` between 0 and 64, inclusive. Returns:long the bitstring, as a `long` with the last bit read stored in the least significant bit. Exceptions IOException: if an I/O error occurs. IllegalArgumentException: if `numBits` is not between 0 and 64, inclusive. EOFException: if the stream reaches the end before reading all the bits.

public long readBits(int numBits) 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, a java.io.EOFException is thrown.

Parameters

numBits:int: the number of bits to read, as an int between 0 and 64, inclusive.

Returns:long

the bitstring, as a long with the last bit read stored in the least significant bit.

Exceptions

IOException:: if an I/O error occurs.
IllegalArgumentException:: if numBits is not between 0 and 64, inclusive.
EOFException:: if the stream reaches the end before reading all the bits.

readBoolean back to summary

readBoolean	back to summary
public boolean readBoolean() throws IOException Redeclares java.io.DataInput.readBoolean. 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. Returns:boolean a boolean value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the end of the stream is reached.

public boolean readBoolean() throws IOException

Redeclares java.io.DataInput.readBoolean.

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.

Returns:boolean

a boolean value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the end of the stream is reached.

readByte back to summary

readByte	back to summary
public byte readByte() throws IOException Redeclares java.io.DataInput.readByte. 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. Returns:byte a signed byte value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the end of the stream is reached.

public byte readByte() throws IOException

Redeclares java.io.DataInput.readByte.

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.

Returns:byte

a signed byte value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the end of the stream is reached.

readBytes back to summary

readBytes	back to summary
public void readBytes(IIOByteBuffer buf, 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. Parameters buf:IIOByteBuffer an IIOByteBuffer object to be modified. len:int the maximum number of `byte`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `len` is negative. NullPointerException: if `buf` is `null`.

public void readBytes(IIOByteBuffer buf, 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.

Parameters

buf:IIOByteBuffer: an IIOByteBuffer object to be modified.
len:int: the maximum number of bytes to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if len is negative.
NullPointerException:: if buf is null.

readChar back to summary

readChar	back to summary
public char readChar() throws IOException Redeclares java.io.DataInput.readChar. 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. Returns:char an unsigned char value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `readUnsignedShort`

public char readChar() throws IOException

Redeclares java.io.DataInput.readChar.

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.

Returns:char

an unsigned char value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

readUnsignedShort

readDouble back to summary

readDouble	back to summary
public double readDouble() throws IOException Redeclares java.io.DataInput.readDouble. 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. Returns:double a double value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `getByteOrder`

public double readDouble() throws IOException

Redeclares java.io.DataInput.readDouble.

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.

Returns:double

a double value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

getByteOrder

readFloat back to summary

readFloat	back to summary
public float readFloat() throws IOException Redeclares java.io.DataInput.readFloat. 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. Returns:float a float value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `getByteOrder`

public float readFloat() throws IOException

Redeclares java.io.DataInput.readFloat.

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.

Returns:float

a float value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

getByteOrder

readFully back to summary

readFully	back to summary
public void readFully(byte[] b, int off, int len) throws IOException Redeclares java.io.DataInput.readFully. Reads `len` bytes from the stream, and stores them into `b` starting at index `off`. If the end of the stream is reached, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters b:byte[] an array of bytes to be written to. off:int the starting position within `b` to write to. len:int the maximum number of `byte`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `b.length`. NullPointerException: if `b` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

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

Redeclares java.io.DataInput.readFully.

Reads len bytes from the stream, and stores them into b starting at index off. If the end of the stream is reached, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

b:byte[]: an array of bytes to be written to.
off:int: the starting position within b to write to.
len:int: the maximum number of bytes to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than b.length.
NullPointerException:: if b is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readFully back to summary

readFully	back to summary
public void readFully(byte[] b) throws IOException Redeclares java.io.DataInput.readFully. Reads `b.length` bytes from the stream, and stores them into `b` starting at index `0`. If the end of the stream is reached, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters b:byte[] an array of `byte`s. Exceptions IOException: if an I/O error occurs. NullPointerException: if `b` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

public void readFully(byte[] b) throws IOException

Redeclares java.io.DataInput.readFully.

Reads b.length bytes from the stream, and stores them into b starting at index 0. If the end of the stream is reached, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

b:byte[]: an array of bytes.

Exceptions

IOException:: if an I/O error occurs.
NullPointerException:: if b is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readFully back to summary

readFully	back to summary
public void readFully(short[] s, int off, int len) 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, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters s:short[] an array of shorts to be written to. off:int the starting position within `s` to write to. len:int the maximum number of `short`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `s.length`. NullPointerException: if `s` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

public void readFully(short[] s, int off, int len) 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, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

s:short[]: an array of shorts to be written to.
off:int: the starting position within s to write to.
len:int: the maximum number of shorts to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than s.length.
NullPointerException:: if s is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readFully back to summary

readFully	back to summary
public void readFully(char[] c, 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, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters c:char[] an array of chars to be written to. off:int the starting position within `c` to write to. len:int the maximum number of `char`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `c.length`. NullPointerException: if `c` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

public void readFully(char[] c, 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, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

c:char[]: an array of chars to be written to.
off:int: the starting position within c to write to.
len:int: the maximum number of chars to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than c.length.
NullPointerException:: if c is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readFully back to summary

readFully	back to summary
public void readFully(int[] i, 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, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters i:int[] an array of ints to be written to. off:int the starting position within `i` to write to. len:int the maximum number of `int`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `i.length`. NullPointerException: if `i` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

public void readFully(int[] i, 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, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

i:int[]: an array of ints to be written to.
off:int: the starting position within i to write to.
len:int: the maximum number of ints to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than i.length.
NullPointerException:: if i is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readFully back to summary

readFully	back to summary
public void readFully(long[] l, 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, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters l:long[] an array of longs to be written to. off:int the starting position within `l` to write to. len:int the maximum number of `long`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `l.length`. NullPointerException: if `l` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

public void readFully(long[] l, 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, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

l:long[]: an array of longs to be written to.
off:int: the starting position within l to write to.
len:int: the maximum number of longs to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than l.length.
NullPointerException:: if l is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readFully back to summary

readFully	back to summary
public void readFully(float[] f, 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, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters f:float[] an array of floats to be written to. off:int the starting position within `f` to write to. len:int the maximum number of `float`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `f.length`. NullPointerException: if `f` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

public void readFully(float[] f, 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, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

f:float[]: an array of floats to be written to.
off:int: the starting position within f to write to.
len:int: the maximum number of floats to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than f.length.
NullPointerException:: if f is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readFully back to summary

readFully	back to summary
public void readFully(double[] d, 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, a `java.io.EOFException` will be thrown. The bit offset within the stream is reset to zero before the read occurs. Parameters d:double[] an array of doubles to be written to. off:int the starting position within `d` to write to. len:int the maximum number of `double`s to read. Exceptions IOException: if an I/O error occurs. IndexOutOfBoundsException: if `off` is negative, `len` is negative, or `off + len` is greater than `d.length`. NullPointerException: if `d` is `null`. EOFException: if the stream reaches the end before reading all the bytes.

public void readFully(double[] d, 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, a java.io.EOFException will be thrown.

The bit offset within the stream is reset to zero before the read occurs.

Parameters

d:double[]: an array of doubles to be written to.
off:int: the starting position within d to write to.
len:int: the maximum number of doubles to read.

Exceptions

IOException:: if an I/O error occurs.
IndexOutOfBoundsException:: if off is negative, len is negative, or off + len is greater than d.length.
NullPointerException:: if d is null.
EOFException:: if the stream reaches the end before reading all the bytes.

readInt back to summary

readInt	back to summary
public int readInt() throws IOException Redeclares java.io.DataInput.readInt. 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. Returns:int a signed int value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `getByteOrder`

public int readInt() throws IOException

Redeclares java.io.DataInput.readInt.

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.

Returns:int

a signed int value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

getByteOrder

readLine back to summary

readLine	back to summary
public String readLine() throws IOException Redeclares java.io.DataInput.readLine. 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. Returns:String a String containing a line of text from the stream. Exceptions IOException: if an I/O error occurs.

public String readLine() throws IOException

Redeclares java.io.DataInput.readLine.

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.

Returns:String

a String containing a line of text from the stream.

Exceptions

IOException:: if an I/O error occurs.

readLong back to summary

readLong	back to summary
public long readLong() throws IOException Redeclares java.io.DataInput.readLong. 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. Returns:long a signed long value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `getByteOrder`

public long readLong() throws IOException

Redeclares java.io.DataInput.readLong.

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.

Returns:long

a signed long value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

getByteOrder

readShort back to summary

readShort	back to summary
public short readShort() throws IOException Redeclares java.io.DataInput.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. The bit offset within the stream is reset to zero before the read occurs. Returns:short a signed short value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `getByteOrder`

public short readShort() throws IOException

Redeclares java.io.DataInput.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.

The bit offset within the stream is reset to zero before the read occurs.

Returns:short

a signed short value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

getByteOrder

readUnsignedByte back to summary

readUnsignedByte	back to summary
public int readUnsignedByte() throws IOException Redeclares java.io.DataInput.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. 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 `byte` values, will be mapped into positive integers between `128` and `255`. The bit offset within the stream is reset to zero before the read occurs. Returns:int an unsigned byte value from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if the end of the stream is reached.

public int readUnsignedByte() throws IOException

Redeclares java.io.DataInput.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.

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 byte values, will be mapped into positive integers between 128 and 255.

The bit offset within the stream is reset to zero before the read occurs.

Returns:int

an unsigned byte value from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the end of the stream is reached.

readUnsignedInt back to summary

readUnsignedInt	back to summary
public long readUnsignedInt() 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. Returns:long an unsigned int value from the stream, as a long. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `getByteOrder`

public long readUnsignedInt() 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.

Returns:long

an unsigned int value from the stream, as a long.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

getByteOrder

readUnsignedShort back to summary

readUnsignedShort	back to summary
public int readUnsignedShort() throws IOException Redeclares java.io.DataInput.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. The bit offset within the stream is reset to zero before the read occurs. Returns:int an unsigned short value from the stream, as an int. Exceptions IOException: if an I/O error occurs. EOFException: if the stream reaches the end before reading all the bytes. See Also `getByteOrder`

public int readUnsignedShort() throws IOException

Redeclares java.io.DataInput.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.

The bit offset within the stream is reset to zero before the read occurs.

Returns:int

an unsigned short value from the stream, as an int.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if the stream reaches the end before reading all the bytes.

See Also

getByteOrder

readUTF back to summary

readUTF	back to summary
public String readUTF() throws IOException Redeclares java.io.DataInput.readUTF. 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))` If the first byte of a group matches the bit pattern `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))` If the first byte of a group matches the pattern `1111xxxx` or the pattern `10xxxxxx`, then a `UTFDataFormatException` is thrown. If end of file is encountered at any time during this entire process, then a `java.io.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. Returns:String a String read from the stream. Exceptions IOException: if an I/O error occurs. EOFException: if this stream reaches the end before reading all the bytes. UTFDataFormatException: if the bytes do not represent a valid modified UTF-8 encoding of a string.

public String readUTF() throws IOException

Redeclares java.io.DataInput.readUTF.

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))

If the first byte of a group matches the bit pattern 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))

If the first byte of a group matches the pattern 1111xxxx or the pattern 10xxxxxx, then a UTFDataFormatException is thrown.

If end of file is encountered at any time during this entire process, then a java.io.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.

Returns:String

a String read from the stream.

Exceptions

IOException:: if an I/O error occurs.
EOFException:: if this stream reaches the end before reading all the bytes.
UTFDataFormatException:: if the bytes do not represent a valid modified UTF-8 encoding of a string.

reset back to summary

reset	back to summary
public void reset() throws IOException 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. Exceptions IOException: if an I/O error occurs.

public void reset() throws IOException

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.

Exceptions

IOException:: if an I/O error occurs.

seek back to summary

seek	back to summary
public void seek(long pos) 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; a `java.io.EOFException` will be thrown only if a read is performed. Parameters pos:long a `long` containing the desired file pointer position. Exceptions IOException: if any other I/O error occurs. IndexOutOfBoundsException: if `pos` is smaller than the flushed position.

public void seek(long pos) 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; a java.io.EOFException will be thrown only if a read is performed.

Parameters

pos:long: a long containing the desired file pointer position.

Exceptions

IOException:: if any other I/O error occurs.
IndexOutOfBoundsException:: if pos is smaller than the flushed position.

setBitOffset back to summary

setBitOffset	back to summary
public void setBitOffset(int bitOffset) 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. Parameters bitOffset:int the desired offset, as an `int` between 0 and 7, inclusive. Exceptions IOException: if an I/O error occurs. IllegalArgumentException: if `bitOffset` is not between 0 and 7, inclusive. See Also `getBitOffset`

public void setBitOffset(int bitOffset) 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.

Parameters

bitOffset:int: the desired offset, as an int between 0 and 7, inclusive.

Exceptions

IOException:: if an I/O error occurs.
IllegalArgumentException:: if bitOffset is not between 0 and 7, inclusive.

See Also

getBitOffset

setByteOrder back to summary

setByteOrder	back to summary
public void setByteOrder(ByteOrder byteOrder) 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`). Parameters byteOrder: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 Also `java.nio.ByteOrder`, `getByteOrder`, `readBits(int)`

public void setByteOrder(ByteOrder byteOrder)

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).

Parameters

byteOrder: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.

skipBytes back to summary

skipBytes	back to summary
public int skipBytes(int n) throws IOException Redeclares java.io.DataInput.skipBytes. 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. Parameters n:int an `int` containing the number of bytes to be skipped. Returns:int an `int` representing the number of bytes skipped. Exceptions IOException: if an I/O error occurs.

public int skipBytes(int n) throws IOException

Redeclares java.io.DataInput.skipBytes.

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.

Parameters

n:int: an int containing the number of bytes to be skipped.

Returns:int

an int representing the number of bytes skipped.

Exceptions

IOException:: if an I/O error occurs.

skipBytes back to summary

skipBytes	back to summary
public long skipBytes(long 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. Parameters n:long a `long` containing the number of bytes to be skipped. Returns:long a `long` representing the number of bytes skipped. Exceptions IOException: if an I/O error occurs.

public long skipBytes(long 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.

Parameters

n:long: a long containing the number of bytes to be skipped.

Returns:long

a long representing the number of bytes skipped.

Exceptions

IOException:: if an I/O error occurs.

public Interface ImageInputStream

Method Summary

Method Detail