Functional and Reactive Programming Using RxJava 2

Session: Lambda Expressions; Collections and Streams

Lesson: Introduction to Lambda Expressions

• Functional vs OO Programming
• Anonymous Inner classes
• Lambda Expression Syntax
• Functional Interfaces
• Method references
• Constructor references

Lesson: Java 8 Collection Updates

• Introduce the ConcurrentHashMap
• Lambda expressions and Collections
• Exercise: Functional Collection

Lesson: Streams

• Processing Collections of data
• The Stream interface
• Reduction and Parallelism
• Filtering collection data
• Sorting Collection data
• Map collection data
• Find elements in Stream
• Numeric Streams
• Create infinite Streams
• Sources for using Streams
• Exercise: Working with Streams

Lesson: Collectors

• Creating Collections from a Stream
• Group elements in the Stream
• Multi-level grouping of elements
• Partitioning Streams
• Exercise: Collecting

Session: Multithreading and Concurrency

Lesson: Java 8 Concurrency Updates

• The common thread pool
• Atomic variables
• LongAdder and LongAccumulator
• CompletableFuture
• Non-blocking asynchronous tasks
• Exercise: CompletableFuture

Session: Introduction to RXJava2

Lesson: Introduction

• Introduce ReactiveX and RxJava 2
• The Observer and Iterator pattern and functional programming
• Introduce the RxJava 2 Building blocks
• Discuss hot and cold observables
• Registering operators
• Subscribing to an Observable
• Exercise: RxJava Introduction

Lesson: Testing Event Sources (Introduction)

• Introduce the TestObserver and TestSubscriber
• Testing Observable implementations
• Introduce some commonly used assertions
• Exercise: Testing the Observable

Lesson: Operators

• Introduce RxJava 2 Operators
• Show the use of RxMarbles (marble diagrams)
• Explain some commonly used operators
• Callback operators
• Exercise: RxJava Operations

Lesson: Creating the event publisher

• Implementing the event source
• Introduce the different types of event publishers
• Convenience methods for creation of publishers
• Creating an event source using an Emitter
• Pre-defined observables
• The defer operator
• ConnectableObservable
• Exercise: RxJava Observables

Session: Working with RxJava2

Lesson: Subjects

• RxJava subjects
• Enable multicating using Subjects
• Introduce most commonly used Subject implementations
• Exercise: RxJava Subjects

Lesson: RxJava Schedulers (Multithreading)

• Thread usage of Observable, Operator and Observer
• Using the subscribeOn method
• Introduce the Scheduler implementations
• Using the observeOn method

Lesson: Testing (multi-threaded) Event Sources

• Testing Asynchronous code
• Discuss strategies for testing event sources
• Waiting for source to complete (await methods)
• Use RxJava extension mechanism to Scheduler instances used during test
• The JUnit 5 @ExtendsWith and @RegisterExtension annotations
• Using the TestScheduler to advance time during test
• Exercise: Testing Asynchronous Event sources

Lesson: Backpressure

• Strategies for dealing with Backpressure
• Reactive Streams
• Flowable and Processor
• “reactive pull” backpressure
• Exercise: RxJava Backpressure

Lesson: Exception Handling

• Handling errors in onError
• Exception handling strategies
• Using onErrorReturn or onErrorNext operators
• Using the retry operators
• The Global Error Handler
• Exercise: Exception Handling