Represents a class ID (16 bytes). Unlike other little-endian * type the {@link ClassID} is not just 16 bytes stored in the wrong * order. Instead, it is a double word (4 bytes) followed by two * words (2 bytes each) followed by 8 bytes.
* * @author Rainer Klute <klute@rainer-klute.de> * @version $Id$ * @since 2002-02-09 */ public class ClassID { /** *The bytes making out the class ID in correct order, * i.e. big-endian.
*/ protected byte[] bytes; /** *Creates a {@link ClassID} and reads its value from a byte * array.
* * @param src The byte array to read from. * @param offset The offset of the first byte to read. */ public ClassID(final byte[] src, final int offset) { read(src, offset); } /** *Creates a {@link ClassID} and initializes its value with * 0x00 bytes.
*/ public ClassID() { bytes = new byte[LENGTH]; for (int i = 0; i < LENGTH; i++) bytes[i] = 0x00; } /**The number of bytes occupied by this object in the byte * stream.
*/ public static final int LENGTH = 16; /** * @return The number of bytes occupied by this object in the byte * stream. */ public int length() { return LENGTH; } /** *Gets the bytes making out the class ID. They are returned in * correct order, i.e. big-endian.
* * @return the bytes making out the class ID. */ public byte[] getBytes() { return bytes; } /** *Reads the class ID's value from a byte array by turning * little-endian into big-endian.
* * @param src The byte array to read from * * @param offset The offset within the src byte array * * @return A byte array containing the class ID. */ public byte[] read(final byte[] src, final int offset) { bytes = new byte[16]; /* Read double word. */ bytes[0] = src[3 + offset]; bytes[1] = src[2 + offset]; bytes[2] = src[1 + offset]; bytes[3] = src[0 + offset]; /* Read first word. */ bytes[4] = src[5 + offset]; bytes[5] = src[4 + offset]; /* Read second word. */ bytes[6] = src[7 + offset]; bytes[7] = src[6 + offset]; /* Read 8 bytes. */ for (int i = 8; i < 16; i++) bytes[i] = src[i + offset]; return bytes; } /** *Writes the class ID to a byte array in the * little-endian.
* * @param dst The byte array to write to. * * @param offset The offset within the dst byte array. * * @exception ArrayStoreException if there is not enough room for the class * ID 16 bytes in the byte array after the offset position. */ public void write(final byte[] dst, final int offset) throws ArrayStoreException { /* Check array size: */ if (dst.length < 16) throw new ArrayStoreException ("Destination byte[] must have room for at least 16 bytes, " + "but has a length of only " + dst.length + "."); /* Write double word. */ dst[0 + offset] = bytes[3]; dst[1 + offset] = bytes[2]; dst[2 + offset] = bytes[1]; dst[3 + offset] = bytes[0]; /* Write first word. */ dst[4 + offset] = bytes[5]; dst[5 + offset] = bytes[4]; /* Write second word. */ dst[6 + offset] = bytes[7]; dst[7 + offset] = bytes[6]; /* Write 8 bytes. */ for (int i = 8; i < 16; i++) dst[i + offset] = bytes[i]; } /** *Checks whether this ClassID is equal to another
* object.
PropertySet with
* @return true if the objects are equal, else
* false.
*/
public boolean equals(final Object o)
{
if (o == null || !(o instanceof ClassID))
return false;
final ClassID cid = (ClassID) o;
if (bytes.length != cid.bytes.length)
return false;
for (int i = 0; i < bytes.length; i++)
if (bytes[i] != cid.bytes[i])
return false;
return true;
}
/**
* Returns a human readable representation of the Class ID
* in standard format "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}"
* @return String representation of the Class ID represented
* by this object.
*/
public String toString()
{
StringBuffer sbClassId = new StringBuffer( 38);
sbClassId.append( '{');
for( int i=0; i < 16; i++) {
sbClassId.append( HexDump.toHex( bytes[ i]));
if( i == 3 || i == 5 || i == 7 || i == 9) {
sbClassId.append( '-');
}
}
sbClassId.append( '}');
return sbClassId.toString();
}
/**
* @see Object#hashCode()
*/
public int hashCode()
{
return new String(bytes).hashCode();
}
}