Java Reference
In-Depth Information
AND (&) 0000100001000000 size(64), length(10)
0000110001100000 size(64), length(11)
0000101101000000 size(64), length(10)
----------------
OR (|) 0000111101100000 size(64), length(11)
0000110001100000 size(64), length(11)
0000101101000000 size(64), length(10)
----------------
XOR (^) 0000011100100000 size(64), length(11)
Caution
Unlike
Vector
and
Hashtable
,
BitSet
is not synchronized. You
mustexternallysynchronizeaccesstothisclasswhenusing
BitSet
inamultithreaded
context.
The Collections Framework has made
Vector
,
Stack
,
Dictionary
, and
Hashtable
obsolete. These types continue to be part of the standard class library to
support legacy code.
The framework's
Iterator
interface has largely obsoleted the
Enumeration
interface. However, because the
java.util.StringTokenizer
class (which is
this interface still has some credibility.
The Preferences API (see Appendix C) has made
Properties
largely obsolete.
However,thestandardclasslibrarystilluses
Properties
invariousplaces(suchas
in the context of XSLT, discussed in
Chapter 10
)
. You'll probably have a few uses for
this class as well.
Because
BitSet
isstillrelevant,thisclasscontinuestobeimproved.Forexample,
Java 7 introduces new
valueOf()
class methods (such as
static BitSet
valueOf(byte[] bytes)
) and instance methods (such as
int previ-
ousSetBit(int fromIndex)
) into this class.
Note
Itisnotsurprisingthat
BitSet
isstillbeingimproved(asrecentlyasJava7
attimeofwriting)whenyourealizetheusefulnessofvariable-lengthbitsets.Because
oftheircompactnessandotheradvantages,variable-lengthbitsetsareoftenusedtoim-
plement an operating system's priority queues and facilitate memory page allocation.
Unix-orientedfilesystemsalsousebitsetstofacilitatetheallocationof
inodes
(inform-
