What is a Java Package

Defining a Package

If you omit the package statement, the class names are put into the default package, which has no name.This is the general form of the package statement:

package packageName;

Create a hierarchy of packages.

To create a hierarchy of packages, separate each package name from the one above it by use of a period. The general form of a multileveled package statement:

package pkg1[.pkg2[.pkg3]];

A package hierarchy must be reflected in the file system of your Java development system.

Java package maps to directory

A Short Package Example

package MyPack;

public class Main {
  public static void main(String args[]) {
    System.out.println("hi");
  }
}  

Then try executing the class, using the following command line:

java MyPack.Main