Converting Between a BitSet and a Byte Array : Bitwise Operators « Operators « Java Tutorial

import java.util.BitSet;

public class Main {
  public static void main(String[] argv) throws Exception {
     System.out.println(fromByteArray(new byte[]{1,2,3}));
  }

  // Returns a bitset containing the values in bytes.
  public static BitSet fromByteArray(byte[] bytes) {
    BitSet bits = new BitSet();
    for (int i = 0; i < bytes.length * 8; i++) {
      if ((bytes[bytes.length - i / 8 - 1] & (1 << (i % 8))) > 0) {
        bits.set(i);
      }
    }
    return bits;
  }
}
//{0, 1, 9, 16}

3.5.Bitwise Operators
	3.5.1.	The Bitwise Operators can be applied to the integer types, long, int, short, char, and byte.
	3.5.2.	The Bitwise Logical Operators
	3.5.3.	Bitwise AND (&)
	3.5.4.	Bitwise OR (\|)
	3.5.5.	Bitwise XOR (^)
	3.5.6.	Left shift (<<)
	3.5.7.	Bitwise complement (~): inverts ones and zeros in a number
	3.5.8.	Demonstrate the bitwise logical operators
	3.5.9.	All bitwise operators in action
	3.5.10.	Bitwise Operator Assignments
	3.5.11.	The Left Shift
	3.5.12.	Left shifting as a quick way to multiply by 2
	3.5.13.	The Right Shift
	3.5.14.	The Unsigned Right Shift
	3.5.15.	Signed shift to the right
	3.5.16.	Unsigned shifting a byte value.
	3.5.17.	Convert a number to negative and back
	3.5.18.	Performing Bitwise Operations on a Bit Vector
	3.5.19.	Converting Between a BitSet and a Byte Array
	3.5.20.	Returns a byte array of at least length 1
	3.5.21.	Use bitwise operator to create hash code
	3.5.22.	Operations on bit-mapped fields.
	3.5.23.	Represents a collection of 64 boolean (on/off) flags.