Combining two bytes in Java

问题

Having two bytes, how to make a new byte by taking the first 3 bits from the first byte and the last 5 from the second ?

For instance, how would that for 11100000 and 00011111 ==> 11111111 ?

I am using Java.

回答1:

byte b1, b2;

take first 3 bits: b1 & 0xE0

take last 5 bits: b2 & 0x1F

concatenate: b1 | b2

回答2:

You can use the BitSet class. There's an example in here.

回答3:

Using the masks 0xE0 (11100000) and 0x1F (00011111), you can mask out the bits you don't want and bitwise or them together:

byte b1 = 123; // 01111011
byte b2 = 50;  // 00110010

byte b3 = (b1 & 0xE0) | (b2 & 0x1F);  // = 114  01110010

回答4:

(b1 & 0xe0) | (b2 & 0x1f)

来源：https://stackoverflow.com/questions/11947138/combining-two-bytes-in-java