Package: java.util
The java.util package contains the collections framework, legacy collection classes, event model, date and time facilities, internationalisation, and miscellaneous utility classes (a string tokenizer, a random-number generator, and a bit array).
Target Audience
This section is for readers that want to learn the basic java programming. The java.util package is necessary to learn since it provides the important classes necessary in learning java. Not only that this is to be learn by novice programmer but this package must also be mastered by an expert programmer as the java.util package is the foundation of a java programming.
Compatibility Version
Since JDK 1.0
java.util Package Classes
The following are the classes under the java.lang package. Please master the majority of these classes as these are all helpful.
| Class | Description |
|---|---|
| Arrays | This class contains various methods for manipulating arrays (such as sorting and searching). Due to these helpful various methods, Arrays class are definitely a must to learn. |
| Calendar | The Calendar class is an abstract class that provides methods for converting between a specific instant in time and a set of calendar fields such as YEAR, MONTH, DAY_OF_MONTH, HOUR, and so on, and for manipulating the calendar fields, such as getting the date of the next week. |
| Currency | This class represents Currency. Anything that got to do with currency, this class will be helpful. |
| HashMap | Hash table based implementation of the Map interface. |
| HashSet | This class implements the Set interface, backed by a hash table (actually a HashMap instance). |
| Scanner | A simple text scanner which can parse primitive types and strings using regular expressions. |
| StringTokenozer | The StringTokenizer class as the name implies allows an application to break a string into tokens. |