Packages and Interfaces
- 1. Packages & Interfaces Presented by: Anindita Mandal Amar Kr Soni Alekhya Pandey Akashdeep Singha Roy Akash Das Akansha Kumari Aishik Das
- 2. What are ‘Packages’ in JAVA?A Package can be defined as a grouping of related types (classes, interfaces, enumerations and annotations ) providing access protection and namespace management. It can be further categorized in two types:
- 3. • We were storing all the coded files inside the same directory, what if, someday we need to make a project? • As the applications grows it becomes difficult to keep all the files in same directory, also we need to ensure that the name we choose should be unique. To address this problem java introduces a mechanism to manage all the classes this is called Packages What does it mean actually? • Let’s see… Directory Structure showing the inbuilt packages
- 4. • Now, the inbuilt packages will be available to user with all use cases, but what if we need to do something which is not pre-defined? • We’ll be creating our own packages. • Lets see how! By default I wrote all files here inside this directory. Now if I’ve to create a package. Firstly, creating a new directory Creating new files inside the directory Now, the package name should be the same as directory name
- 5. • Now, if we want to access the package Test.*; Represents all files inside the Test directory On running this, we get Inside Test, class sample is present. By this we can observe that the package is properly imported.
- 6. What are ‘Interfaces’ in JAVA?• An interface in java is a blueprint of a class. • It has static constants and abstract methods. • The interface in java is a mechanism to achieve abstraction. Just like a class can inherit or extend from another class, similarly the interface can inherit or extend from another interface
- 7. How do we declare an interface?• Let’s see the syntax for writing an interface… • An interface is implicitly abstract. • So not need to use the abstract keyword while declaring an interface. • Each Fields in an interface is also implicitly static and final, so the static and final keyword is not needed (Refer below diagram). • Methods in an interface are also implicitly public.
- 8. Creating an interface Implementing the interface Completing the body of the abstract method After running the program Interface helps us getting an implementation of multi-parent inheritance which is not there in JAVA
- 9. References https://www.javatpoint.com/package https://www.tutorialspoint.com/java/java_packages.htm https://www.geeksforgeeks.org/packages-in-java/ https://docs.oracle.com/javase/tutorial/java/concepts/package.html https://www.geeksforgeeks.org/interfaces-in-java/ https://www.javatpoint.com/interface-in-java https://www.tutorialspoint.com/java/java_interfaces.htm
- 10. Thank You “I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.” ― AlbertEinstein Now, thought for the day,