com.goldencode.p2j.ui

Class ImageExtractor.BmpFileReader

java.lang.Object

com.goldencode.p2j.ui.ImageExtractor.BmpFileReader

All Implemented Interfaces:

ImageExtractor.ImageReader

Enclosing class:

ImageExtractor

public static class ImageExtractor.BmpFileReader
extends java.lang.Object
implements ImageExtractor.ImageReader

Helps to extract an image encoded according to bitmap file format (BMP): BITMAPFILEHEADER stores general information about the bitmap image BITMAPINFOHEADER stores image details, defines the pixel format RGBGUAD[] stores the color table BYTE[] stores the pixel data

Field Summary

Fields

Modifier and Type	Field and Description
static byte	BITMAPINFOHEADER_MARKER Represents the size of BITMAPINFOHEADER marker.
static byte[]	BM_MARKER Represents the first two bytes of a BMP image file.
private int	imageSize Stores the image data size.
private int	index Stores the current index.
private byte[]	output Stores the extracted image data.

Constructor Summary

Constructors

Constructor and Description
BmpFileReader()

Method Summary

Modifier and Type	Method and Description
byte[]	getImageData() Returns the binary image data.
java.lang.String	getImageFileExtension() Returns the BMP image standard extension.
int	getImageIndex() Returns the current image count as its index value, a 1-based index.
private boolean	hasMarker(byte firstByte, byte secondByte) Test if the first two bytes can be the beginning of the bmp data.
boolean	nextImage(java.io.RandomAccessFile raf) Extracts a first available BMP image data starting from the current file offset.
private int	readImageSize(java.io.RandomAccessFile raf) Try to read the next 4 bytes and interprets the data as little-endian data that stores the bmp image size.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

BM_MARKER

public static final byte[] BM_MARKER

Represents the first two bytes of a BMP image file.

BITMAPINFOHEADER_MARKER

public static final byte BITMAPINFOHEADER_MARKER

Represents the size of BITMAPINFOHEADER marker.

See Also:

Constant Field Values

output

private byte[] output

Stores the extracted image data.

imageSize

private int imageSize

Stores the image data size.

index

private int index

Stores the current index.

Constructor Detail

BmpFileReader

public BmpFileReader()

Method Detail

nextImage

public boolean nextImage(java.io.RandomAccessFile raf)
                  throws java.io.IOException

Extracts a first available BMP image data starting from the current file offset. It scans the given stream looking for the first occurrence of BMP binary data and stores the binary in its internal state and returns true immediately after the first occurrence of the target image has been found, moving the current position next to the found BMP image, otherwise it returns false and shifts the current position one more toward the end of the given stream.

Specified by:

nextImage in interface ImageExtractor.ImageReader

Parameters:

raf - The data represented by the random access file

Returns:

True iff the target bmp image is read successfully into its internal byte array, otherwise false.

Throws:

java.io.IOException - If IO error occurs while reading data and moving the current file pointer.

getImageData

public byte[] getImageData()

Returns the binary image data.

Specified by:

getImageData in interface ImageExtractor.ImageReader

Returns:

The binary image data

getImageIndex

public int getImageIndex()

Returns the current image count as its index value, a 1-based index.

Specified by:

getImageIndex in interface ImageExtractor.ImageReader

Returns:

The image index

getImageFileExtension

public java.lang.String getImageFileExtension()

Returns the BMP image standard extension.

Specified by:

getImageFileExtension in interface ImageExtractor.ImageReader

Returns:

The file image standard extension.

hasMarker

private boolean hasMarker(byte firstByte,
                          byte secondByte)

Test if the first two bytes can be the beginning of the bmp data.

Parameters:

firstByte - The first byte

secondByte - The second byte

Returns:

Iff the given bytes can be the beginning of the bmp data.

readImageSize

private int readImageSize(java.io.RandomAccessFile raf)
                   throws java.io.IOException

Try to read the next 4 bytes and interprets the data as little-endian data that stores the bmp image size.

Parameters:

raf - The data represented by the random access file

Returns:

The integer that can represent the target image size iff not EOF, otherwise returns -1 that means EOF reached.

Throws:

java.io.IOException - Iff IO error occurs during this reading operation.