Thread: Send Hex data in a UDP frame

Please edit your post and wrap your code with code tags:
[code=java]
YOUR CODE HERE
[/code]
to get highlighting and preserve formatting.

If you want bytes of hex data vs bytes of character data you should build the bytes in a byte array instead of using a StringBuilder. For example is this what you want to send:
byte[] theBytes = {0x00, 0x01, 0x04, 0x00, 0x41, 0x54 };

Can you post the code that shows where you have: 0001044154
Is it in a String?
Where did the data come from?

datagram know thats a commands in hex format.

Not sure what that means.
0x41 is a way to represent what is in a byte in a hex format.
'A' is the same data in character format
0b01000001 is the same data in binary format
and 65 in decimal format.

All three of the above are exactly the same bits in a byte. I've shown 3 different ways to represent the same contents of that byte.

The String class has a method to get a byte array from a String.
Use the Arrays class's toString() method to print out the content of the byte array to see what is there.
The values will be printed as decimal vs as hex: 65 = 0x41 and 84 = 0x54

Create a String
use the String class's method to get an array of bytes from the String
Put that byte array into the UDP buffer

For debug/testing use the Arrays class's toString() method to format the array for printing:
System.out.println("an ID "+ java.util.Arrays.toString(theArrayName));