Introduction to Reactive Spring

Course Objectives

Reactive Spring focuses on providing an understanding of the fundamental principles and technologies that are used in reactive programming.  This understanding is critical to being able to diagnose, troubleshoot, tune, and perform other lifecycle activities.

Working within in an engaging, hands-on learning environment, guided by our expert team, you'll learn to:

• Understand the ReactiveX specification
• Understand the basics of Reactive Programming
• Discuss the advantages and limitations of Observables
• Write a client application capable of handling Reactive events
• Apply operators to event streams to filter, modify and combine the objects emitted by event publishers
• Select the appropriate type of Event Source
• Use both Cold and Hot Observables
• Deal with backpressure problems in reactive programming
• Develop a reactive web application using Spring WebFlux
• Define application flows of a WebFlux application
• Use the WebClient API to work with both synchronous and streaming APIs
• Develop Unit and Integration tests to test WebFlux endpoints
• Creating a reactive REST endpoint
• Become familiar with the basics of WebSockets
• Create a WebSocket endpoint using Spring
• Create a WebSocket client
• Understand the basics of NoSQL
• Become familiar with the basics of MongoDB
• Understand how the data in MongoDB can be retrieved using a Reactive API
• Define Spring Data MongoDB repositories
• Query the MongoDB using Spring Data
• Define a reactive repository using MongoDB
• Explore the Spring Data R2DBC API to perform reactive CRUD operations against a relational database

Need different skills or topics?  If your team requires different topics or tools, additional skills or custom approach, this course may be further adjusted to accommodate.  We offer additional Spring, programming, Microservices / Services, REST, TDD / testing, design, application security and other related topics that may be blended with this course for a track that best suits your needs. Our team will collaborate with you to understand your needs and will target the course to focus on your specific learning objectives and goals.

Course Prerequisites

This in an intermediate-level Java development course geared for students experienced with Java and Spring programming essentials.  This course does not cover Java or Spring development basics.

Please see the Related Courses tab for specific Pre-Requisite courses, Related Courses that offer similar skills or topics, and next-step Learning Path recommendations.

Course Agenda

Please note that this list of topics is based on our standard course offering, evolved from typical industry uses and trends. We’ll work with you to tune this course and level of coverage to target the skills you need most.

Session: Introduction to Reactive Programming

Lesson: Introduction to Reactive Programming

• Reactive Manifesto
• Introduce ReactiveX
• ReactiveX implementations
• The Observer, Iterator pattern and functional programming
• Discuss hot and cold publishers

Lesson: Reactive Streams API

• Introduce the Reactive Streams specification
• Publisher and Subscribers
• java.util.concurrent.Flow
• Transformation of Messages (Processor)
• Controlling messages
• Tutorial: Setup Eclipse for Using Maven

Session: Project Reactor

Lesson: Introduction

• Introduce the Reactor Building blocks
• Flux and Mono
• Creating observables
• Subscribing to a stream
• Lab: Project Reactor introduction

Lesson: Testing Event Sources (introduction)

• Testing reactive implementations
• StepVerifier : test sequence of emitted items
• Defining expectations
• TestPublisher: produce test data to test downstream operators
• Lab: Project Reactor Testing

Lesson: Reactive Operators

• Introduce Operators
• Show the use of marble diagrams
• Explain some commonly used operators
• Callback operators
• Lab: Project Reactor Operators

Lesson: Schedulers (Multithreading)

• Thread usage of subscriber and consumer
• Using the subscribeOn method
• Introduce the Scheduler interface
• Using the observeOn method

Lesson: Backpressure

• Strategies for dealing with Backpressure
• “reactive pull” backpressure
• Lab: Reactor Backpressure

Lesson: Exception Handling

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

Session: Spring Data R2DBC

Lesson: Spring Data Review

• Quick review of Spring Data repositories
• Query return types
• Defining Query methods
• Pagination and sorting

Lesson: R2DBC

• Reactive Relational Database Connectivity
• DatabaseClient
• Performing CRUD operations
• Reactive Query annotated methods
• Lab: Spring Data R2DBC

Session: Spring WebFlux

Lesson: Introduction

• Annotated Controllers
• Functional Endpoints
• WebFlux configuration
• Creating a reactive REST endpoint
• Lab: Introduction to Spring WebFlux

Lesson: Defining flows

• Defining the application flow
• Actions
• Defining decision
• Navigating flows
• RouterFunction
• Lab: WebFlux, Defining Flows

Lesson: View Technologies

• View technologies
• Using Thymeleaf to create the view
• View Configuration
• Lab: WebFlux View technologies

Session: Spring WebClient

Lesson: Introduction to WebClient

• Working with asynchronous and streaming APIs
• Making requests
• Handling the response
• Lab: WebClient

Lesson: WebTestClient

• Testing WebFlux server endpoints
• Testing controllers or functions
• Define integration tests
• Lab: WebTestClient

Session: Spring Reactive WebSockets

Lesson: Introduction to WebSockets

• Be familiar with the basics of WebSockets
• Understand the HTTP handshake and upgrade
• Name some of the advantages of WebSockets

Lesson: Defining the WebSocket

• WebSocket Message Handling
• WebSocketSession
• Implementing the WebSockethandler
• Creating a Browser WebSocket Client
• Lab: Spring WebSocket Introduction

Lesson: WebSocket STOMP

• Streaming (or Simple) text-orientated messaging protocol
• Introduce SockJS
• Connecting to the STOMP endpoint
• Configuring the message broker
• STOMP destinations
• Lab: Spring WebSocket STOMP

Lesson: Reactive WebSocket

• Reactive WebSocket support
• Implement the reactive WebSocketHandler

Session: NOSQL and MongoDB

Lesson: BigData

• Introduce Big Data
• Explain the need for enhanced data storage

Lesson: Introduction to MongoDB

• JavaScript Object Notation Overview
• Introduce Binary JSON (BSON)
• Starting the database
• Creating Collections and Documents
• Executing ‘simple’ database commands
• Introduce the ObjectID
• Searching for documents using query operators
• Updating and deleting documents
• MongoDB Compass
• Lab: Introduction to MongoDB

Session: Spring and MongoDB

Lesson: Spring and MongoDB

• MongoDB Support in Spring Data
• MongoClient and MongoTemplate
• Spring Data MongoDB configuration
• @EnableMongoRepositories
• Adding documents to the database
• The @Document and @Field annotations
• Polymorphism and the _class property
• The Criteria object
• Lab: Spring MongoDB

Lesson: Spring Data MongoDB

• MongoRepository
• Field naming strategy
• Using JSON queries to find documents
• The @PersistenceConstructor annotation
• Lab: Spring Mongo repositories

Lesson: Reactive Repositories with MongoDB

• Using reactive repositories
• ReactiveMongoTemplate
• RxJava or Reactor
• Lab: Spring Mongo reactive repositories

Course Materials

Student Materials: Each participant will receive a digital Student Guide and/or Course Notes, code samples, software tutorials, step-by-step written lab instructions (as applicable), diagrams and related reference materials and resource links. Students will also receive the project files (or code, if applicable) and solutions required for the hands-on work.

Hands-On Setup Made Simple! Our dedicated tech team will work with you to ensure our ‘easy-access’ cloud-based course environment, or local installation, is accessible, fully-tested and verified as ready to go well in advance of the course start date, ensuring a smooth start to class and effective learning experience for all participants. In some cases we can also help you install this course locally if preferred. Please inquire for details and options.

Every-Course Extras = High-Value & Long-Term Learning Support! All Public Schedule courses include our unique EveryCourse Extras package (Course Recordings, Live Instructor Follow-on Support, Free *Live* Course Refresh Re-Takes, early access to Special Offers, Free Courses & more). Please inquire for details.