public static String getMD5(byte[] source) {
	  String s = null;
	  char hexDigits[] = {      
			  '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',  'e', 'f'}; 
	   try
	   {
	    java.security.MessageDigest md = java.security.MessageDigest.getInstance( "MD5" );
	    md.update( source );
	    byte tmp[] = md.digest(); 
	    char str[] = new char[16 * 2];   
	                                                 
	    int k = 0;                                
	    for (int i = 0; i < 16; i++) {         	                                                 
	     byte byte0 = tmp[i];                
	     str[k++] = hexDigits[byte0 >>> 4 & 0xf];   
	                                                             
	     str[k++] = hexDigits[byte0 & 0xf];           
	    } 
	    s = new String(str);                                 

	   }catch( Exception e )
	   {
	    e.printStackTrace();
	   }
	   return s;
	 }