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Java 8 Essential Training

Using abstract classes and methods

From the course: Java 8 Essential Training

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  • Course details

    If you want to build applications for mobile devices, desktop computers, or the web, you need to know Java. This course provides the foundation for learning Java SE (Standard Edition), so you can build your first apps or start exploring the language on your own. Author David Gassner shows how to install Java and the IntelliJ IDEA IDE, and start working with variables, data types, keywords, and other critical language components. He also helps you control program flow with conditional logic and loops, store data with the Java Collections Framework, and understand how Java implements object-oriented coding principles such as inheritance and polymorphism.

    Instructor

    • Click here to view David Gassner’s instructor page

      David Gassner

      Managing Staff Instructor, LinkedIn Learning Technology Library at LinkedIn

      David Gassner is the author of over 60 video-based technical training courses for software developers.

      David is a senior staff instructor who specializes in development platforms and programming languages including Android and Java. He currently creates training content for Android developers and content that covers multiple programming languages including Java, C#, Visual Basic, and Go. He was formerly the president and founder of Bardo Technical Services, an Adobe Solutions Network Training Provider. As an Adobe Certified Expert, he wrote courseware for Adobe and delivered extensive training on Flex, ColdFusion, Dreamweaver and Flash. He was the author of Wiley's Flex 3 Bible and Flash Builder 4 and Flex 4 Bible. He most recently designed and developed Audio Cues—an Android app for running sound in live performances—which is available in the Google Play store.

    Skills covered in this course

  • Welcome

    - When designing an object-oriented, contract-based programming architecture, you can frequently choose between using interfaces and abstract classes. An abstract class is abstract because you add the abstract keyword and then it can contain a mixture of fully implemented methods and abstract methods. An abstract method is just like a method in an interface. It doesn't have an implementation. It just indicates the method signature and then any subclasses of an abstract method must implement that method. In this project, the Olive class is the superclass for two subclasses, Ligurian and Kalamata. I'm going to change this class and make it abstract by adding the abstract keyword after public and before the keyword class. Now that doesn't change any behavior on its own. I'll run the application and show that everything still works. But now, I'll declare an abstract method as part of this class. I'll place this new method down here after all the setters and getters, but before toString…

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Contents