byte[] header = new byte[] {'B', 1, 0, 0,
         /*bodylen*/ 0, 0, 0, 0,
         /*serial*/ 0, 0, 0, 1,
         /*headerarraylen*/ 0, 0, 0, 48,
         /*headerstruct 16*/ 3, 1, 's', 0, 0, 0, 0, 5, 'H', 'e', 'l', 'l', 'o', 0, 0, 0,
         /*headerstruct 32*/ 6, 1, 's', 0, 0, 0, 0, 20, 'o', 'r', 'g', '.', 'f', 'r', 'e', 'e', 'd', 'e', 's', 'k', 't', 'o', 'p', '.', 'D', 'B', 'u', 's', 0, 0, 0, 0
      }; 

000000  42 01 00 00 00 00 00 00 00 00 00 01 00 00 00 30 03 01  B..............0..
000012  73 00 00 00 00 05 48 65 6C 6C 6F 00 00 00 06 01 73 00  s.....Hello.....s.
000024  00 00 00 14 6F 72 67 2E 66 72 65 65 64 65 73 6B 74 6F  ...org.freedeskto
000036  70 2E 44 42 75 73 00 00 00 00                          p.DBus....

With path and interface:

000000  42 01 00 00 00 00 00 00 00 00 00 01 00 00 00 70 03 01  B..............p..
000012  73 00 00 00 00 05 48 65 6C 6C 6F 00 00 00 02 01 73 00  s.....Hello.....s.
000024  00 00 00 14 6F 72 67 2E 66 72 65 65 64 65 73 6B 74 6F  ...org.freedeskto
000036  70 2E 44 42 75 73 00 00 00 00 01 01 73 00 00 00 00 15  p.DBus......s....
000048  2F 6F 72 67 2F 66 72 65 65 64 65 73 6B 74 6F 70 2F 44  /org/freedesktop/D
00005A  42 75 73 00 00 00 06 01 73 00 00 00 00 14 6F 72 67 2E  Bus.....s....org.
00006C  66 72 65 65 64 65 73 6B 74 6F 70 2E 44 42 75 73 00 00  freedesktop.DBus..
00007E  00 00                                                  ..