JavaFX 24 · com.sun.javafx.iio.png.PNGIDATChunkInputStream

A stream which exposes only the IDAT chunk data content of a PNG stream.

Once all IDAT chunks have been read, the read() methods will return -1 and isFoundAllIDATChunks() true. Once isFoundAllIDATChunks() returns true, the length and type of the first chunk after the last IDAT chunk may be found by calling getNextChunkLength() and getNextChunkType(), respectively. The source stream will at this point be positioned at the first byte of the data field after the last IDAT chunk (which could be the first byte of the CRC code if the length is zero).

Field Summary

Modifier and Type	Field and Description
private boolean	foundAllIDATChunks
pack-priv static final int	IDAT_TYPE
private int	nextChunkLength
private int	nextChunkType
private int	numBytesAvailable
private DataInputStream	source

Constructor Summary

Access	Constructor and Description
pack-priv	PNGIDATChunkInputStream(DataInputStream stream positioned at the beginning of the data field of the first IDAT chunk in the PNG stream. input, int the length of the data field of the first IDAT chunk. firstIDATChunkLength) Create the stream.

Method Summary

Modifier and Type	Method and Description
pack-priv int	getNextChunkLength()
pack-priv int	getNextChunkType()
pack-priv boolean	isFoundAllIDATChunks()
private void	nextChunk()
public int	read() Implements abstract java.io.InputStream.read. Reads the next byte of data from the input stream.
public int	read(byte[] the buffer into which the data is read. b, int the start offset in array `b` at which the data is written. off, int the maximum number of bytes to read. len) Overrides java.io.InputStream.read. Reads up to `len` bytes of data from the input stream into an array of bytes.

Inherited from java.io.InputStream:: available close mark markSupported nullInputStream read readAllBytes readNBytes readNBytes reset skip skipNBytes transferTo

Field Detail

foundAllIDATChunks	back to summary
private boolean foundAllIDATChunks

IDAT_TYPE	back to summary
pack-priv static final int IDAT_TYPE

nextChunkLength	back to summary
private int nextChunkLength

nextChunkType	back to summary
private int nextChunkType

numBytesAvailable	back to summary
private int numBytesAvailable

source	back to summary
private DataInputStream source

Constructor Detail

PNGIDATChunkInputStream	back to summary
pack-priv PNGIDATChunkInputStream(DataInputStream input, int firstIDATChunkLength) throws IOException Create the stream. Parameters input:DataInputStream stream positioned at the beginning of the data field of the first IDAT chunk in the PNG stream. firstIDATChunkLength:int the length of the data field of the first IDAT chunk.

PNGIDATChunkInputStream

back to summary

pack-priv PNGIDATChunkInputStream(DataInputStream input, int firstIDATChunkLength) throws IOException

Create the stream.

Parameters

input:DataInputStream: stream positioned at the beginning of the data field of the first IDAT chunk in the PNG stream.
firstIDATChunkLength:int: the length of the data field of the first IDAT chunk.

Method Detail

getNextChunkLength	back to summary
pack-priv int getNextChunkLength()

getNextChunkType	back to summary
pack-priv int getNextChunkType()

isFoundAllIDATChunks	back to summary
pack-priv boolean isFoundAllIDATChunks()

nextChunk	back to summary
private void nextChunk() throws IOException

read back to summary

read	back to summary
public int read() throws IOException Implements abstract java.io.InputStream.read. Doc from java.io.InputStream.read. Reads the next byte of data from the input stream. The value byte is returned as an `int` in the range `0` to `255`. If no byte is available because the end of the stream has been reached, the value `-1` is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown. Returns:int the next byte of data, or `-1` if the end of the stream is reached. Annotations @Override Exceptions IOException: if an I/O error occurs.

public int read() throws IOException

Implements abstract java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Returns:int

the next byte of data, or -1 if the end of the stream is reached.

Annotations

@Override

Exceptions

IOException:: if an I/O error occurs.

read back to summary

read	back to summary
public int read(byte[] b, int off, int len) throws IOException Overrides java.io.InputStream.read. Doc from java.io.InputStream.read. Reads up to `len` bytes of data from the input stream into an array of bytes. An attempt is made to read as many as `len` bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown. If `len` is zero, then no bytes are read and `0` is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value `-1` is returned; otherwise, at least one byte is read and stored into `b`. The first byte read is stored into element `b[off]`, the next one into `b[off+1]`, and so on. The number of bytes read is, at most, equal to `len`. Let k be the number of bytes actually read; these bytes will be stored in elements `b[off]` through `b[off+`k`-1]`, leaving elements `b[off+`k`]` through `b[off+len-1]` unaffected. In every case, elements `b[0]` through `b[off-1]` and elements `b[off+len]` through `b[b.length-1]` are unaffected. Parameters b:byte[] the buffer into which the data is read. off:int the start offset in array `b` at which the data is written. len:int the maximum number of bytes to read. Returns:int the total number of bytes read into the buffer, or `-1` if there is no more data because the end of the stream has been reached. Annotations @Override Exceptions IOException: If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.

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

Overrides java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off-1] and elements b[off+len] through b[b.length-1] are unaffected.