Packages in Java

When you use a class such as ArrayList, you need to know the
"package" it belongs to.

For example, ArrayList belongs to the java.util package.
To use it, you either use an import statement:


import java.util.ArrayList;

or type the full name of the package:



  java.util.ArrayList<Integer> list = new java.util.ArrayList<Integer>();

Note that the above line of code uses the "new" syntax from Java 5.0
that can be used to restrict the type of an ArrayList to contain
only items of the wrapper class Integer.










See Also:
     Head First Java, 2nd Edition, pp 155-157, 587-595.