sun.security.util
Class BitArray

java.lang.Object
  sun.security.util.BitArray

public class BitArray
extends Object

A packed array of booleans.

Constructor Summary

BitArray(boolean[] bits)
Create a BitArray whose bits are those of the given array of Booleans.

BitArray(int length)
Creates a BitArray of the specified size, initialized to zeros.

BitArray(int length, byte[] a)
Creates a BitArray of the specified size, initialized from the specified byte array.

Method Summary

Object	clone() Creates and returns a copy of this object.
boolean	equals(Object obj) Indicates whether some other object is "equal to" this one.
boolean	get(int index) Returns the indexed bit in this BitArray.
int	hashCode() Returns a hash code value for this bit array.
int	length() Returns the length of this BitArray.
void	set(int index, boolean value) Sets the indexed bit in this BitArray.
boolean[]	toBooleanArray() Return a boolean array with the same bit values a this BitArray.
byte[]	toByteArray() Returns a Byte array containing the contents of this BitArray.
String	toString() Returns a string representation of this BitArray.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BitArray

public BitArray(int length)
         throws IllegalArgumentException

Creates a BitArray of the specified size, initialized to zeros.

Throws:

IllegalArgumentException

BitArray

public BitArray(int length,
                byte[] a)
         throws IllegalArgumentException

Creates a BitArray of the specified size, initialized from the specified byte array. The most significant bit of a[0] gets index zero in the BitArray. The array a must be large enough to specify a value for every bit in the BitArray. In other words, 8*a.length <= length.

Throws:

IllegalArgumentException

BitArray

public BitArray(boolean[] bits)

Create a BitArray whose bits are those of the given array of Booleans.

Method Detail

get

public boolean get(int index)
            throws ArrayIndexOutOfBoundsException

Returns the indexed bit in this BitArray.

Throws:

ArrayIndexOutOfBoundsException

set

public void set(int index,
                boolean value)
         throws ArrayIndexOutOfBoundsException

Sets the indexed bit in this BitArray.

Throws:

ArrayIndexOutOfBoundsException

length

public int length()

Returns the length of this BitArray.

toByteArray

public byte[] toByteArray()

Returns a Byte array containing the contents of this BitArray. The bit stored at index zero in this BitArray will be copied into the most significant bit of the zeroth element of the returned byte array. The last byte of the returned byte array will be contain zeros in any bits that do not have corresponding bits in the BitArray. (This matters only if the BitArray's size is not a multiple of 8.)

equals

public boolean equals(Object obj)

Description copied from class: Object

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

Overrides:

equals in class Object

Parameters:

obj - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

See Also:

Object.hashCode(), Hashtable

toBooleanArray

public boolean[] toBooleanArray()

Return a boolean array with the same bit values a this BitArray.

hashCode

public int hashCode()

Returns a hash code value for this bit array.

Overrides:

hashCode in class Object

Returns:

a hash code value for this bit array.

See Also:

Object.equals(java.lang.Object), Hashtable

clone

public Object clone()

Description copied from class: Object

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

 x.clone() != x

will be true, and that the expression:

 x.clone().getClass() == x.getClass()

will be true, but these are not absolute requirements. While it is typically the case that:

 x.clone().equals(x)

will be true, this is not an absolute requirement.

By convention, the returned object should be obtained by calling super.clone. If a class and all of its superclasses (except Object) obey this convention, it will be the case that x.clone().getClass() == x.getClass().

By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by super.clone before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by super.clone need to be modified.

The method clone for class Object performs a specific cloning operation. First, if the class of this object does not implement the interface Cloneable, then a CloneNotSupportedException is thrown. Note that all arrays are considered to implement the interface Cloneable. Otherwise, this method creates a new instance of the class of this object and initializes all its fields with exactly the contents of the corresponding fields of this object, as if by assignment; the contents of the fields are not themselves cloned. Thus, this method performs a "shallow copy" of this object, not a "deep copy" operation.

The class Object does not itself implement the interface Cloneable, so calling the clone method on an object whose class is Object will result in throwing an exception at run time.

Overrides:

clone in class Object

Returns:

a clone of this instance.

See Also:

Cloneable

toString

public String toString()

Returns a string representation of this BitArray.

Overrides:

toString in class Object

Returns:

a string representation of the object.