Java byte count to hexadecimal string representation design principle and implementation method

Java byte count to hexadecimal string representation design principle and implementation method

1. When the lower four bits, the need to meet the high four bits all zero, and low four-bit unchanged, so &0x0f, so that the two conditions can be satisfied at the same time.
   

2. When you take a height of four bits, you need to shift the byte number to the left >> four bits, as above.

The program is implemented as follows:

public class Demo9 {
public static void Main (string[] args) {
SYSTEM.OUT.PRINTLN (Convert ((byte) 105));
}
Static String convert (Byte b) {
int low = B & 0x0f;
int high = (b>>4) & 0x0f;
Char[] arr = {' 0 ', ' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ', ' 6 ', ' 7 ', ' 8 ', ' 9 ', ' A ', ' B ', ' C ', ' D ', ' E ', ' F '};
Return "" +arr[high] +arr[low];
}
}

Java byte count to hexadecimal string representation design principle and implementation method