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LinkedIn Learning

Java Essential Training: Objects and APIs

via LinkedIn Learning


Learn Java 9, in part two of our essential training series. Learn about debugging, creating custom classes, working with inheritance, and more.

If you want to build applications for mobile devices, desktop computers, or the web, you need to know Java—and keep your knowledge up to date as the language evolves. Java 9 is changing quite a few important aspects of the programming workflow, particularly the handling of objects and APIs. This course is the second in the Java Essential Training series, which provides the foundation for learning Java 9. Instructor David Gassner starts by showing how to debug Java code in IntelliJ IDEA, and handle any exceptions that occur. He explains how to create custom classes and understand how Java implements inheritance, a core principle of object-oriented programming. Plus, learn how to store data in memory with the Java Collections Framework, extend Java with popular APIs, make network requests, and package your applications for deployment in JAR files.


  • Welcome
  • What you should know
  • How to use the exercise files
  • Which version of Java do you want to learn?
1. Exception Handling and Debugging
  • Syntax errors vs. exceptions
  • Debug with IntelliJ IDEA
  • Handle exceptions with try-catch
  • Create multiple catch blocks
  • Checked vs. unchecked exceptions
2. Create Custom Classes
  • About encapsulation
  • Use the Java runtime classes
  • Wrap code in static methods
  • Declare and use custom classes
  • Organize code with packages
  • Create and use instance methods
  • Manage state with instance variables
  • Declare multiple constructor methods
  • Use static fields as constants
  • Declare and use enum types
  • Organize code with nested types
3. Work with Inheritance
  • About inheritance and polymorphism
  • Extend classes and override methods
  • Cast objects as different types
  • Create and implement interfaces
  • Use abstract classes and methods
4. Manage Data Collections
  • Store values in simple arrays
  • Manage resizable arrays with List
  • Manage key-value pairs with Map
5. Use Java Packages and Libraries
  • Work with dates and times
  • Copy files with readers and buffers
  • Copy files with Path and Files classes
  • Parse a JSON file
  • Include packages with modules
6. Prepare a Java Application for Deployment
  • Document code with Javadoc
  • Package classes in JAR files
  • Next steps

Taught by

David Gassner

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