Packages are a collection of related classes. These packages are gathered together to attempt to avoid conflicts between classes. There are two categories of classes: Built-in packages and User-Defined packages.
These are packages that are included in the Java Development Environment (JDE) and are free to use in your applications. The math class is included in the java.lang package.
More information on W3Schools.
Frequently Used Standard Packages
| Package Name | Description |
|---|---|
java.long |
Classes that support the basic language features and the handling of arrays and strings. Classes in this package are always directly in your programs by default because this package is always automatically loaded with your program. |
java.io |
Classes for stream input and output operations. |
java.nio.file |
Classes for file input and output. |
java.util |
Utility classes of various kinds, including classes for managing data within collections or groups of data items. |
javax.swing |
These classes of various kinds, including classes for managing data within collections or groups of data items. |
java.awt |
Classes in this package provide the original GUI components (DJK 1.1) as well as some basic support necessary for Swing components. |
java.awt.geom |
These classes define two-dimensional geometric shapes |
java.awt.event |
The classes in this package are used in the implementation of windowed applications to handle events in your program. Events are things such as moving the mouse, pressing the left mouse button, or clicking on a menu item. |