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.