BitSet

public class BitSet extends Object
implements Cloneable Serializable

This class implements a vector of bits that grows as needed. Each component of the bit set has a boolean value. The bits of a BitSet are indexed by nonnegative integers. Individual indexed bits can be examined, set, or cleared. One BitSet may be used to modify the contents of another BitSet through logical AND, logical inclusive OR, and logical exclusive OR operations.

By default, all bits in the set initially have the value false.

Every bit set has a current size, which is the number of bits of space currently in use by the bit set. Note that the size is related to the implementation of a bit set, so it may change with implementation. The length of a bit set relates to logical length of a bit set and is defined independently of implementation.

Unless otherwise noted, passing a null parameter to any of the methods in a BitSet will result in a NullPointerException.

A BitSet is not safe for multithreaded use without external synchronization.

Public Constructor Summary

BitSet()
Creates a new bit set.
BitSet(int nbits)
Creates a bit set whose initial size is large enough to explicitly represent bits with indices in the range 0 through nbits-1.

Public Method Summary

void
and(BitSet set)
Performs a logical AND of this target bit set with the argument bit set.
void
andNot(BitSet set)
Clears all of the bits in this BitSet whose corresponding bit is set in the specified BitSet.
int
cardinality()
Returns the number of bits set to true in this BitSet.
void
clear(int fromIndex, int toIndex)
Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to false.
void
clear(int bitIndex)
Sets the bit specified by the index to false.
void
clear()
Sets all of the bits in this BitSet to false.
Object
clone()
Cloning this BitSet produces a new BitSet that is equal to it.
boolean
equals(Object obj)
Compares this object against the specified object.
void
flip(int bitIndex)
Sets the bit at the specified index to the complement of its current value.
void
flip(int fromIndex, int toIndex)
Sets each bit from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to the complement of its current value.
boolean
get(int bitIndex)
Returns the value of the bit with the specified index.
BitSet
get(int fromIndex, int toIndex)
Returns a new BitSet composed of bits from this BitSet from fromIndex (inclusive) to toIndex (exclusive).
int
hashCode()
Returns the hash code value for this bit set.
boolean
intersects(BitSet set)
Returns true if the specified BitSet has any bits set to true that are also set to true in this BitSet.
boolean
isEmpty()
Returns true if this BitSet contains no bits that are set to true.
int
length()
Returns the "logical size" of this BitSet: the index of the highest set bit in the BitSet plus one.
int
nextClearBit(int fromIndex)
Returns the index of the first bit that is set to false that occurs on or after the specified starting index.
int
nextSetBit(int fromIndex)
Returns the index of the first bit that is set to true that occurs on or after the specified starting index.
void
or(BitSet set)
Performs a logical OR of this bit set with the bit set argument.
int
previousClearBit(int fromIndex)
Returns the index of the nearest bit that is set to false that occurs on or before the specified starting index.
int
previousSetBit(int fromIndex)
Returns the index of the nearest bit that is set to true that occurs on or before the specified starting index.
void
set(int fromIndex, int toIndex, boolean value)
Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to the specified value.
void
set(int fromIndex, int toIndex)
Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to true.
void
set(int bitIndex)
Sets the bit at the specified index to true.
void
set(int bitIndex, boolean value)
Sets the bit at the specified index to the specified value.
int
size()
Returns the number of bits of space actually in use by this BitSet to represent bit values.
IntStream
stream()
Returns a stream of indices for which this BitSet contains a bit in the set state.
byte[]
toByteArray()
Returns a new byte array containing all the bits in this bit set.
long[]
toLongArray()
Returns a new long array containing all the bits in this bit set.
String
toString()
Returns a string representation of this bit set.
static BitSet
valueOf(long[] longs)
Returns a new bit set containing all the bits in the given long array.
static BitSet
valueOf(byte[] bytes)
Returns a new bit set containing all the bits in the given byte array.
static BitSet
valueOf(ByteBuffer bb)
Returns a new bit set containing all the bits in the given byte buffer between its position and limit.
static BitSet
valueOf(LongBuffer lb)
Returns a new bit set containing all the bits in the given long buffer between its position and limit.
void
xor(BitSet set)
Performs a logical XOR of this bit set with the bit set argument.

Inherited Method Summary