Package org.apache.commons.imaging.common

Class BinaryFunctions

java.lang.Object

org.apache.commons.imaging.common.BinaryFunctions

public final class BinaryFunctions
extends Object

Convenience methods for various binary and I/O operations.

Method Summary

Modifier and Type	Method	Description
static int	charsToQuad(char c1, char c2, char c3, char c4)
static boolean	compareBytes(byte[] a, int aStart, byte[] b, int bStart, int length)
static int	findNull(byte[] src, int start, String message)
static int	findNull(byte[] src, String message)
static byte[]	getBytes(RandomAccessFile raf, long pos, int length, String exception)
static byte[]	head(byte[] bytes, int count)
static void	logByteBits(String msg, byte i)
static void	logCharQuad(String msg, int i)
static void	printCharQuad(PrintWriter pw, String msg, int i)
static byte[]	quadsToByteArray(int quad)	Convert a quad into a byte array.
static int	read2Bytes(String name, InputStream is, String exception, ByteOrder byteOrder)
static int	read3Bytes(String name, InputStream is, String exception, ByteOrder byteOrder)
static int	read4Bytes(String name, InputStream is, String exception, ByteOrder byteOrder)
static long	read8Bytes(String name, InputStream is, String exception, ByteOrder byteOrder)	Read eight bytes from the specified input stream, adjust for byte order, and return a long integer.
static void	readAndVerifyBytes(InputStream is, byte[] expected, String exception)
static void	readAndVerifyBytes(InputStream is, BinaryConstant expected, String exception)
static byte	readByte(String name, InputStream is, String exceptionMessage)
static byte[]	readBytes(InputStream is, int count)
static byte[]	readBytes(String name, InputStream is, int length)
static byte[]	readBytes(String name, InputStream is, int length, String exception)
static byte[]	remainingBytes(String name, byte[] bytes, int count)
static boolean	searchQuad(int quad, InputStream bis)	Consumes the InputStream (without closing it) searching for a quad.
static long	skipBytes(InputStream is, long length)
static long	skipBytes(InputStream is, long length, String exception)
static byte[]	slice(byte[] bytes, int start, int count)
static boolean	startsWith(byte[] buffer, byte[] search)
static boolean	startsWith(byte[] buffer, BinaryConstant search)

Methods inherited from class java.lang.Object

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

Method Details

charsToQuad

public static int charsToQuad(char c1,
 char c2,
 char c3,
 char c4)

compareBytes

public static boolean compareBytes(byte[] a,
 int aStart,
 byte[] b,
 int bStart,
 int length)

findNull

public static int findNull(byte[] src,
 int start,
 String message)
                    throws ImagingException

Throws:

ImagingException

findNull

public static int findNull(byte[] src,
 String message)
                    throws ImagingException

Throws:

ImagingException

getBytes

public static byte[] getBytes(RandomAccessFile raf,
 long pos,
 int length,
 String exception)
                       throws IOException

Throws:

IOException

head

public static byte[] head(byte[] bytes,
 int count)

logByteBits

public static void logByteBits(String msg,
 byte i)

logCharQuad

public static void logCharQuad(String msg,
 int i)

printCharQuad

public static void printCharQuad(PrintWriter pw,
 String msg,
 int i)

quadsToByteArray

public static byte[] quadsToByteArray(int quad)

Convert a quad into a byte array.

Parameters:

quad - quad

Returns:

a byte array

read2Bytes

public static int read2Bytes(String name,
 InputStream is,
 String exception,
 ByteOrder byteOrder)
                      throws IOException

Throws:

IOException

read3Bytes

public static int read3Bytes(String name,
 InputStream is,
 String exception,
 ByteOrder byteOrder)
                      throws IOException

Throws:

IOException

read4Bytes

public static int read4Bytes(String name,
 InputStream is,
 String exception,
 ByteOrder byteOrder)
                      throws IOException

Throws:

IOException

read8Bytes

public static long read8Bytes(String name,
 InputStream is,
 String exception,
 ByteOrder byteOrder)
                       throws IOException

Read eight bytes from the specified input stream, adjust for byte order, and return a long integer.

Parameters:

name - a descriptive identifier used for diagnostic purposes

is - a valid input stream

exception - application-defined message to be used for constructing an exception if an error condition is triggered.

byteOrder - the order in which the InputStream marshals data

Returns:

a long integer interpreted from next 8 bytes in the InputStream

Throws:

IOException - in the event of a non-recoverable error, such as an attempt to read past the end of file.

readAndVerifyBytes

public static void readAndVerifyBytes(InputStream is,
 BinaryConstant expected,
 String exception)
                               throws ImagingException,
IOException

Throws:

ImagingException

IOException

readAndVerifyBytes

public static void readAndVerifyBytes(InputStream is,
 byte[] expected,
 String exception)
                               throws ImagingException,
IOException

Throws:

ImagingException

IOException

readByte

public static byte readByte(String name,
 InputStream is,
 String exceptionMessage)
                     throws IOException

Throws:

IOException

readBytes

public static byte[] readBytes(InputStream is,
 int count)
                        throws IOException

Throws:

IOException

readBytes

public static byte[] readBytes(String name,
 InputStream is,
 int length)
                        throws IOException

Throws:

IOException

readBytes

public static byte[] readBytes(String name,
 InputStream is,
 int length,
 String exception)
                        throws IOException

Throws:

IOException

remainingBytes

public static byte[] remainingBytes(String name,
 byte[] bytes,
 int count)

searchQuad

public static boolean searchQuad(int quad,
 InputStream bis)
                          throws IOException

Consumes the InputStream (without closing it) searching for a quad. It will stop either when the quad is found, or when there are no more bytes in the input stream.

Returns true if it found the quad, and false otherwise.

Parameters:

quad - a quad (the needle)

bis - an input stream (the haystack)

Returns:

true if it found the quad, and false otherwise

Throws:

IOException - if it fails to read from the given input stream

skipBytes

public static long skipBytes(InputStream is,
 long length)
                      throws IOException

Throws:

IOException

skipBytes

public static long skipBytes(InputStream is,
 long length,
 String exception)
                      throws IOException

Throws:

IOException

slice

public static byte[] slice(byte[] bytes,
 int start,
 int count)

startsWith

public static boolean startsWith(byte[] buffer,
 BinaryConstant search)

startsWith

public static boolean startsWith(byte[] buffer,
 byte[] search)