This chapter concentrates on various useful classes and methods
in the java.util
package and elsewhere.
& Enumeration - - unlike an array, Vector
objects contain a list of objects that can grow or shrink. The
cycles once through each item in a list such as a Vector.
HashMap and Properties - associative arrays of objects
that use key/value pairs
Framework - other classes and interfaces dealing with collections
& ArrayList - Iterator offers an improved tool
for cycling through each item in a list such as an a ArrayList.
The latter class is similar to Vector
but faster due to no synchronization.
- Generics -
new capability added in J2SE5.0 in which the collections classes
can be restricted at compile-time to a particular class type rather
than only Object.
API - the java.util.prefs
package contains a set of classes that supports a program's user
Utilities in J2SE5.0 - enhanced tools added with J2SE5.0 for
dealing efficiently with threads.
Types in J2SE5.0 - new capability in J2SE5.0 for defiining
a special enum
type that only takes the values of a specified set of constants.
Class - lots of methods for dealing with arrays such as searching
tools: - discussion of various tools for manipulating strings
Calendar and Time - methods for date/time handling
- Other Utilities
- other utilities including more classes and sub-packages of java.util.
- review the recursion programming technique.
- the java.math package provides two classes that can represent
integers of arbitary length and decimals with fractions of arbitrary
- Bit Handling -
we review the various tools in Java for accessing and modifying
bits in number representations.
Latest update: Nov. 19, 2004