converting bits in to integer

Question

I receive a datapacket containing a byte array and I have to get some integer values from it. Here is a part of the documentation. Can someone help me please?

This comes

Answer 1

Assuming you have java 7, you should be able to read the year as

    int year = 1990
    + ((b[0] & 0b1000_0000) << 5)
    + ((b[0] & 0b0100_0000) << 4)
    + ((b[0] & 0b0010_0000) << 3)
    + ((b[0] & 0b0001_0000) << 2)
    + ((b[0] & 0b0000_1000) << 1)
    + ((b[0] & 0b0000_0100));

and the month as

    int month = 1 
    + ((b[0] & 0b1000_0010) << 3)
    + ((b[0] & 0b0100_0001) << 2)
    + ((b[1] & 0b1000_0000) << 1)
    + ((b[1] & 0b0100_0000));

I let you do the others ints in the same way.

I don't have java7 and can't test now, I hope I'm not wrong. It's also possible that the order of the bytes is the reverse one.