org.jscsi.target.util

Class ReadWrite

java.lang.Object

org.jscsi.target.util.ReadWrite

public final class ReadWrite
extends Object

This utility class contains static methods for reading/writing integers of various lengths and character strings from/to ByteBuffer objects and byte arrays.

Author:

Andreas Ergenzinger

Constructor Summary

Constructors

Constructor and Description
ReadWrite()

Method Summary

Methods

Modifier and Type	Method and Description
static void	appendTextDataSegmentToStringBuffer(ByteBuffer byteBuffer, StringBuilder stringBuilder) Appends the content of a ProtocolDataUnit's (text) data segment to a StringBuilder;
static String	byteBufferToString(ByteBuffer buffer) Returns the bytes in a ByteBuffer as a UTF-8 encoded String.
static byte[]	longToBytes(long value) Splits the passed value into bytes and returns them in an array, in big-endian format.
static int	readFourByteInt(byte[] array, int start) Reads a (signed) 4-byte integer from four consecutive big-endian-ordered bytes of a byte array and returns the value.
static int	readFourByteInt(ByteBuffer buffer, int start) Reads a (signed) 4-byte integer from four consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.
static int	readOneByteInt(byte[] array, int start) Reads a specified byte from a byte array and returns its value as an unsigned integer.
static int	readOneByteInt(ByteBuffer buffer, int start) Reads a specified byte from a ByteBuffer and returns its value as an unsigned integer.
static int	readThreeByteInt(byte[] array, int start) Reads an unsigned 3-byte integer from three consecutive big-endian-ordered bytes of a byte array and returns the value.
static int	readThreeByteInt(ByteBuffer buffer, int start) Reads an unsigned 3-byte integer from three consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.
static int	readTwoByteInt(byte[] array, int start) Reads an unsigned 2-byte integer from two consecutive big-endian-ordered bytes of a byte array and returns the value.
static int	readTwoByteInt(ByteBuffer buffer, int start) Reads an unsigned 2-byte integer from two consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.
static long	readUnsignedInt(ByteBuffer buffer, int start) Reads an unsigned 4-byte integer from four consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.
static ByteBuffer[]	stringToTextDataSegments(String string, int bufferSize) Puts the characters in the passed String into an array of one or more ByteBuffers and returns it.
static void	writeInt(int value, ByteBuffer buffer, int start) Writes the given value to the buffer in big-endian format, with the index position of the most significant byte being start.
static void	writeLong(ByteBuffer buffer, long value, int index) Writes the given value to the buffer in big-endian format, with the index position of the most significant byte being index.
static void	writeThreeByteInt(ByteBuffer buffer, int value, int index) Writes the three least-significant big-endian-ordered bytes of an integer the a specified position in a ByteBuffer.
static void	writeTwoByteInt(ByteBuffer buffer, int value, int index) Writes the two least-significant big-endian-ordered bytes of an integer the a specified position in a ByteBuffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReadWrite

public ReadWrite()

Method Detail

readOneByteInt

public static final int readOneByteInt(ByteBuffer buffer,
                 int start)

Reads a specified byte from a ByteBuffer and returns its value as an unsigned integer.

Parameters:

buffer - the ByteBuffer containing the byte

start - the index position of the byte in the ByteBuffer

Returns:

the unsigned integer value of the byte

readOneByteInt

public static final int readOneByteInt(byte[] array,
                 int start)

Reads a specified byte from a byte array and returns its value as an unsigned integer.

Parameters:

array - the array containing the byte

start - the index position of the byte in the array

Returns:

the unsigned integer value of the byte

readTwoByteInt

public static final int readTwoByteInt(ByteBuffer buffer,
                 int start)

Reads an unsigned 2-byte integer from two consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.

Parameters:

buffer - the ByteBuffer containing the bytes

start - the index position of the most-significant byte

Returns:

the unsigned value of the two-byte integer

readTwoByteInt

public static final int readTwoByteInt(byte[] array,
                 int start)

Reads an unsigned 2-byte integer from two consecutive big-endian-ordered bytes of a byte array and returns the value.

Parameters:

array - the byte array containing the bytes

start - the index position of the most-significant byte

Returns:

the unsigned value of the two-byte integer

readThreeByteInt

public static final int readThreeByteInt(ByteBuffer buffer,
                   int start)

Reads an unsigned 3-byte integer from three consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.

Parameters:

buffer - the ByteBuffer containing the bytes

start - the index position of the most-significant byte

Returns:

the unsigned value of the three-byte integer

readThreeByteInt

public static final int readThreeByteInt(byte[] array,
                   int start)

Reads an unsigned 3-byte integer from three consecutive big-endian-ordered bytes of a byte array and returns the value.

Parameters:

array - the byte array containing the bytes

start - the index position of the most-significant byte

Returns:

the unsigned value of the three-byte integer

readFourByteInt

public static final int readFourByteInt(ByteBuffer buffer,
                  int start)

Reads a (signed) 4-byte integer from four consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.

Parameters:

buffer - the ByteBuffer containing the bytes

start - the index position of the most-significant byte

Returns:

the value of the four-byte integer

readFourByteInt

public static final int readFourByteInt(byte[] array,
                  int start)

Reads a (signed) 4-byte integer from four consecutive big-endian-ordered bytes of a byte array and returns the value.

Parameters:

array - the byte array containing the bytes

start - the index position of the most-significant byte

Returns:

the unsigned value of the four-byte integer

stringToTextDataSegments

public static ByteBuffer[] stringToTextDataSegments(String string,
                                    int bufferSize)

Puts the characters in the passed String into an array of one or more ByteBuffers and returns it.

If the String does not end with a null character, one will be appended. If the String's length is larger than the specified bufferSize, all but the last ByteBuffer will have capacity() = bufferSize, the last one will contain the remaining String characters.

Parameters:

string - the String to be put into the ByteBuffer

bufferSize - the maximum size of the returned ByteBuffers

Returns:

an array of ByteBuffers containing the passed String

appendTextDataSegmentToStringBuffer

public static final void appendTextDataSegmentToStringBuffer(ByteBuffer byteBuffer,
                                       StringBuilder stringBuilder)

Appends the content of a ProtocolDataUnit's (text) data segment to a StringBuilder;

Parameters:

byteBuffer - the PDU's data segment

stringBuilder - the StringBuilder that will be extended

writeInt

public static final void writeInt(int value,
            ByteBuffer buffer,
            int start)

Writes the given value to the buffer in big-endian format, with the index position of the most significant byte being start. To get the value back from the buffer, use readUnsignedInt.

Parameters:

value - the integer to write to the ByteBuffer

buffer - where the integer will be stored

start - index of the most significant byte of the stored value

byteBufferToString

public static String byteBufferToString(ByteBuffer buffer)

Returns the bytes in a ByteBuffer as a UTF-8 encoded String.

Parameters:

buffer - a ByteBuffer containing UTF-8 encoded characters.

Returns:

a String representation of the buffer's content

longToBytes

public static byte[] longToBytes(long value)

Splits the passed value into bytes and returns them in an array, in big-endian format.

Parameters:

value - the long to split

Returns:

byte representation of the parameter

writeLong

public static void writeLong(ByteBuffer buffer,
             long value,
             int index)

Writes the given value to the buffer in big-endian format, with the index position of the most significant byte being index.

Parameters:

value - the integer to write to the ByteBuffer

buffer - where the integer will be stored

index - index of the most significant byte of the stored value

writeTwoByteInt

public static void writeTwoByteInt(ByteBuffer buffer,
                   int value,
                   int index)

Writes the two least-significant big-endian-ordered bytes of an integer the a specified position in a ByteBuffer.

Parameters:

buffer - where the bytes will be written

value - the value to convert and copy

index - the position of the most significant byte in the ByteBuffer

writeThreeByteInt

public static void writeThreeByteInt(ByteBuffer buffer,
                     int value,
                     int index)

Writes the three least-significant big-endian-ordered bytes of an integer the a specified position in a ByteBuffer.

Parameters:

buffer - where the bytes will be written

value - the value to convert and copy

index - the position of the most significant byte in the ByteBuffer

readUnsignedInt

public static long readUnsignedInt(ByteBuffer buffer,
                   int start)

Reads an unsigned 4-byte integer from four consecutive big-endian-ordered bytes of a ByteBuffer object and returns the value.

Parameters:

buffer - the ByteBuffer containing the bytes

start - the index position of the most-significant byte

Returns:

the value of the unsigned four-byte integer