org.crosswire.jsword.book.sword
Class SwordUtil

java.lang.Object
  org.crosswire.jsword.book.sword.SwordUtil

public final class SwordUtil
extends Object

Various utilities used by different Sword classes.

Author:

Joe Walker

See Also:

The GNU Lesser General Public License for details.

Field Summary

private static org.slf4j.Logger

log The log stream

Constructor Summary

private

SwordUtil() Prevent instantiation

Method Summary

private static void	clean1252(String key, byte[] data, int offset, int length) Remove rogue characters in the source.
static String	decode(String key, byte[] data, int offset, int length, String charset) Transform a portion of a byte array starting at an offset into a string given the encoding.
static String	decode(String key, byte[] data, int length, String charset) Transform a portion of a byte array into a string given the encoding.
static String	decode(String key, byte[] data, String charset) Transform a byte array into a string given the encoding.
protected static int	decodeLittleEndian16(byte[] data, int offset) Decode little endian data from a byte array
static int	decodeLittleEndian32(byte[] data, int offset) Decode little endian data from a byte array.
protected static void	encodeLittleEndian16(int val, byte[] data, int offset) Encode a 16-bit little endian from an integer.
protected static void	encodeLittleEndian32(int val, byte[] data, int offset) Encode little endian data from a byte array.
protected static int	findByte(byte[] data, byte sought) Find a byte of data in an array
protected static int	findByte(byte[] data, int offset, byte sought) Find a byte of data in an array
static URI	getExpandedDataPath(SwordBookMetaData bookMetaData) Returns where the book should be located
protected static byte[]	readNextRAF(RandomAccessFile raf, int theSize) Read a RandomAccessFile from the current location in the file.
protected static byte[]	readRAF(RandomAccessFile raf, long offset, int theSize) Read a RandomAccessFile
protected static byte[]	readUntilRAF(RandomAccessFile raf, byte stopByte) Read a RandomAccessFile until a particular byte is seen
protected static byte[]	readUntilRAF(RandomAccessFile raf, int offset, byte stopByte) Read a RandomAccessFile until a particular byte is seen
protected static void	writeNextRAF(RandomAccessFile raf, byte[] data)
protected static void	writeRAF(RandomAccessFile raf, long offset, byte[] data) Writes "data" to a RandomAccessFile at the "offset" position

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final org.slf4j.Logger log

The log stream

Constructor Detail

SwordUtil

private SwordUtil()

Prevent instantiation

Method Detail

readRAF

protected static byte[] readRAF(RandomAccessFile raf,
                                long offset,
                                int theSize)
                         throws IOException

Read a RandomAccessFile

Parameters:

raf - The file to read

offset - The start of the record to read

theSize - The number of bytes to read

Returns:

the read data

Throws:

IOException - on error

readNextRAF

protected static byte[] readNextRAF(RandomAccessFile raf,
                                    int theSize)
                             throws IOException

Read a RandomAccessFile from the current location in the file.

Parameters:

raf - The file to read

theSize - The number of bytes to read

Returns:

the read data

Throws:

IOException - on error

writeRAF

protected static void writeRAF(RandomAccessFile raf,
                               long offset,
                               byte[] data)
                        throws IOException

Writes "data" to a RandomAccessFile at the "offset" position

Parameters:

raf - RandomAccessFile

offset - offset to write at

data - data to write

Throws:

IOException - on error

writeNextRAF

protected static void writeNextRAF(RandomAccessFile raf,
                                   byte[] data)
                            throws IOException

Throws:

IOException

readUntilRAF

protected static byte[] readUntilRAF(RandomAccessFile raf,
                                     int offset,
                                     byte stopByte)
                              throws IOException

Read a RandomAccessFile until a particular byte is seen

Parameters:

raf - The file to read

offset - The start of the record to read

stopByte - The point at which to stop reading

Returns:

the read data

Throws:

IOException - on error

readUntilRAF

protected static byte[] readUntilRAF(RandomAccessFile raf,
                                     byte stopByte)
                              throws IOException

Read a RandomAccessFile until a particular byte is seen

Parameters:

raf - The file to read

stopByte - The point at which to stop reading

Returns:

the read data

Throws:

IOException - on error

decodeLittleEndian32

public static int decodeLittleEndian32(byte[] data,
                                       int offset)

Decode little endian data from a byte array. This assumes that the high order bit is not set as this is used solely for an offset in a file in bytes. For a practical limit, 2**31 is way bigger than any document that we can have.

Parameters:

data - the byte[] from which to read 4 bytes

offset - the offset into the array

Returns:

The decoded data

encodeLittleEndian32

protected static void encodeLittleEndian32(int val,
                                           byte[] data,
                                           int offset)

Encode little endian data from a byte array. This assumes that the number fits in a Java integer. That is, the range of an unsigned C integer is greater than a signed Java integer. For a practical limit, 2**31 is way bigger than any document that we can have. If this ever doesn't work, use a long for the number.

Parameters:

val - the number to encode into little endian

data - the byte[] from which to write 4 bytes

offset - the offset into the array

decodeLittleEndian16

protected static int decodeLittleEndian16(byte[] data,
                                          int offset)

Decode little endian data from a byte array

Parameters:

data - the byte[] from which to read 2 bytes

offset - the offset into the array

Returns:

The decoded data

encodeLittleEndian16

protected static void encodeLittleEndian16(int val,
                                           byte[] data,
                                           int offset)

Encode a 16-bit little endian from an integer. It is assumed that the integer's lower 16 bits are the only that are set.

Parameters:

data - the byte[] from which to write 2 bytes

offset - the offset into the array

findByte

protected static int findByte(byte[] data,
                              byte sought)

Find a byte of data in an array

Parameters:

data - The array to search

sought - The data to search for

Returns:

The index of the found position or -1 if not found

findByte

protected static int findByte(byte[] data,
                              int offset,
                              byte sought)

Find a byte of data in an array

Parameters:

data - The array to search

offset - The position in the array to begin looking

sought - The data to search for

Returns:

The index of the found position or -1 if not found

decode

public static String decode(String key,
                            byte[] data,
                            String charset)

Transform a byte array into a string given the encoding. If the encoding is bad then it just does it as a string. Note: this may modify data. Don't use it to examine data.

Parameters:

key - the key

data - The byte array to be converted

charset - The encoding of the byte array

Returns:

a string that is UTF-8 internally

decode

public static String decode(String key,
                            byte[] data,
                            int length,
                            String charset)

Transform a portion of a byte array into a string given the encoding. If the encoding is bad then it just does it as a string. Note: this may modify data. Don't use it to examine data.

Parameters:

key - the key

data - The byte array to be converted

length - The number of bytes to use.

charset - The encoding of the byte array

Returns:

a string that is UTF-8 internally

decode

public static String decode(String key,
                            byte[] data,
                            int offset,
                            int length,
                            String charset)

Transform a portion of a byte array starting at an offset into a string given the encoding. If the encoding is bad then it just does it as a string. Note: this may modify data. Don't use it to examine data.

Parameters:

key - the key

data - The byte array to be converted

offset - The starting position in the byte array

length - The number of bytes to use.

charset - The encoding of the byte array

Returns:

a string that is UTF-8 internally

clean1252

private static void clean1252(String key,
                              byte[] data,
                              int offset,
                              int length)

Remove rogue characters in the source. These are characters that are not valid in cp1252 aka WINDOWS-1252 and in UTF-8 or are non-printing control characters in the range of 0-32.

getExpandedDataPath

public static URI getExpandedDataPath(SwordBookMetaData bookMetaData)
                               throws BookException

Returns where the book should be located

Parameters:

bookMetaData - meta information about the book

Returns:

the URI locating the resource

Throws:

BookException - thrown if an issue is encountered, e.g. missing data files.