SFR | e-Content Development Program

Introduction

Two of Java’s most innovative features :
1. Packages
2. Interfaces.

Packages

Packages are containers for classes that are used to keep the class name space compartmentalized.

Interfaces

Interface, can specify a set of methods that can be implemented by one or more classes. The interface, itself, does not actually define any implementation.

JAVA Packages and Interfaces

Defining Package

Java provides a mechanism for partitioning the class name space into more manageable chunks. To create a package, include a package command as the first statement in a Java source file. … Read more »
Importing Package

Java includes the import statement to bring certain classes, or entire packages, into visibility. Once imported, a class can be referred to directly, using only its name… Read more »
Package example

Example program to define and import a package. … Read more »
Defining Interfaces

Interface can be used to specify what a class must do, but not how it does it. Interfaces are similar to classes, but they lack instance variables, and their methods are declared without any body. … Read more »
Implementing Interface

Once an interface has been defined, one or more classes can implement that interface. To implement an interface, include the implements clause in a class definition, and then create the methods defined by the interface … Read more »
Extending Interfaces

One interface can inherit another by use of the keyword extends. The syntax is the same as for inheriting classes. … Read more »

Introduction

JAVA Packages and Interfaces

Defining Package

Importing Package

Package example

Defining Interfaces

Implementing Interface

Extending Interfaces