Java 17 Essential Training: Objects and APIs

Introduction

• Java objects and APIs
• What you should know

1. Inheritance

• Inheritance between classes
• Constructors in inheritance
• Overriding and overloading inherited methods
• Chain of inheritance
• Limiting access in inheritance
• Sealed classes
• Challenge: Cake! Cake! Cake!
• Solution: Cake! Cake! Cake!

2. Polymorphism

• Polymorphism with objects
• Object typecasting
• instanceof operator

3. Abstraction

• Abstract classes and methods
• Inheriting from abstract classes
• Creating objects with abstract types

4. Interfaces

• Creating an interface
• Implementing interfaces
• Instantiating objects with interface types
• Default and static methods

5. Data Structures

• Collections framework
• Sets
• Lists
• Queues
• Maps
• Iterators
• Enhanced for loops
• forEach() and lambdas
• Challenge: Gradebook
• Solution: Gradebook

6. Functional Programming

• Functional interfaces
• Streams
• Common stream operations

7. Exception Handling

• Try and catch blocks
• Stack trace and exception message
• Checked vs. unchecked exceptions
• Handling multiple exceptions
• Finally block
• Try with resources
• Throwing exceptions
• Rethrowing exceptions

Conclusion

• Next steps