guidcalculationtest.java

eclipseme的最新版本的source,欢迎j2me程序员使用

package preverification.inputs;

public class GUIDCalculationTest
{
	public class GUIDCalculationTestData
	{

		public GUIDCalculationTestData()
		{
		}
		
		public void update(byte[] newbuf, int bufstart, int buflen)
		{
		}

		public void md5final(byte[] digest) 
		{
		}
	}

	private String	guid;
	public void constructGUID(String template, String version)
	{
		// use MD5 as a scrambling function
		GUIDCalculationTestData digester = new GUIDCalculationTestData();
		byte[] digest = new byte[16];
		
		String value = System.getProperty("microedition.platform");
		if (value != null)
		{
			byte[] array = value.getBytes();
			digester.update(array, 0, array.length);
		}
		
		if (template != null)
		{
			byte[] array = template.getBytes();
			digester.update(array, 0, array.length);
		}
		
		if (version != null)
		{
			byte[] array = version.getBytes();
			digester.update(array, 0, array.length);
		}
		
		long theTime = System.currentTimeMillis();
		int i;
		for (i = 0; i < 8; i++)
		{
			digest[i] = (byte)theTime;
			theTime >>= 8;
		}
		digester.update(digest, 0, 8);
		
		// extract the 128 bit digest and "fold" to a 64 bit string
		digester.md5final(digest);
		for (i = 0; i < 8; i++)
		{
			digest[i] ^= digest[i+8];
		}
		
		// append 16 bits of checksum to make an 80 bit string
		int sum1 = 0;
		int sum2 = 0;

		for (i = 0; i < 8; i++)
		{
		    int theByte = (int) digest[i] & 0xFF;

		    sum1 += theByte;
		    sum2 += sum1;
		}

		sum1 %= 255;
		sum2 %= 255;

		int out1 = ((255 * 2 - sum1 - sum2) % 255);
		int out2 = ((255 * 2 - sum1 - out1) % 255);

		digest[8] = (byte) out1;
		digest[9] = (byte) out2;
		
		// reduce into a 16-char string using base 32
		
		StringBuffer buf = new StringBuffer(16);
		buf.append(GUID_CHARS.charAt( (((int)digest[0] & 0xF8) >> 3) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[0] & 0x07) << 2) | (((int)digest[1] & 0xC0) >> 6) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[1] & 0x3E) >> 1) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[1] & 0x01) << 4) | (((int)digest[2] & 0xF0) >> 4) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[2] & 0x0F) << 1) | (((int)digest[3] & 0x80) >> 7) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[3] & 0x7C) >> 2) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[3] & 0x03) << 3) | (((int)digest[4] & 0xE0) >> 5) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[4] & 0x1F) ) ));
		
		buf.append(GUID_CHARS.charAt( (((int)digest[5] & 0xF8) >> 3) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[5] & 0x07) << 2) | (((int)digest[6] & 0xC0) >> 6) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[6] & 0x3E) >> 1) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[6] & 0x01) << 4) | (((int)digest[7] & 0xF0) >> 4) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[7] & 0x0F) << 1) | (((int)digest[8] & 0x80) >> 7) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[8] & 0x7C) >> 2) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[8] & 0x03) << 3) | (((int)digest[9] & 0xE0) >> 5) ));
		buf.append(GUID_CHARS.charAt( (((int)digest[9] & 0x1F) ) ));
		
		this.guid = buf.toString();
	}
	
	private static final String	GUID_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
}