Question

I am using a Java library that has a method that wants a time info.
it is described like this:

public void function(byte[] time);

time: The time is provided in 1/100th seconds since midnight as a three bytes integer, starting with the most significant byte.

I don’t know how to do that. I can get time in milliseconds(Sysem.currentTimeInMillisecond). but that gives me milliseconds past since 1 January 1970.

Can anybody help?

Answer 1

Here is the code I have just written. I think it is self explainable enough. The logic of converting int to byte array is stolen from DataOutputStream.writeInt()

    Calendar c = Calendar.getInstance(); //now

    Calendar m = Calendar.getInstance(); //midnight
    m.set(Calendar.HOUR_OF_DAY, 0);
    m.set(Calendar.MINUTE, 0);
    m.set(Calendar.SECOND, 0);
    m.set(Calendar.MILLISECOND, 0);

    int diff = (int) (c.getTimeInMillis() - m.getTimeInMillis()) ;
    int v = diff / 10;

    byte[] bytes = new byte[4];
    bytes[0] = (byte) ((v >>> 24) & 0xFF);
    bytes[1] = (byte) ((v >>> 16) & 0xFF);
    bytes[2] = (byte) ((v >>>  8) & 0xFF);
    bytes[4] = (byte) ((v >>>  0) & 0xFF);