Jump-Start Microservices on Spring Boot and Spring Cloud

Check the latest docker images, then create a mysql container with port mapping and credentials. Test access by entering the container and verifying the database.

Link and run a Spring Boot app with a MySQL container by building a docker image, starting containers, and hitting localhost:8080 to fetch data.

Create a Spring Boot cloud config server by setting the group and package, selecting the config server dependency, and running the Spring Boot application.

Configure a Spring Boot config server by adding a message in application.properties, reading it with @Value in a configuration class, and printing hello from server on startup via CommandLineRunner.

Create a rest controller in a package, annotate the class, and map a get endpoint at /book that returns a string message.

Connect to an in-memory H2 database with Spring Boot, map a book entity to a book table using JPA annotations, and auto insert two records via data.sql on startup.

Create a JPA repository for the book entity, using repository methods like find all to retrieve books from the database and expose them via a service.

Create a consumer service with dev web, copy the producer’s book entity and lombok dependency, remove database use, and implement a get endpoint for purchased books by isbn and quantity.

Create a spring boot starter project for a books consumer service, add spring web, openfeign, and ribbon for load balancing, and implement a feign client interface named BookFeign.

Call the producer service using a Feign client by creating a get book method with ISBN and quantity, then compute the amount from price and quantity and return the book.

Enable client side balancing with the ribbon pattern in the consumer, using multiple producer instances. Observe load balancing across ports 1882 and 1892 as requests cycle to available producers.

Zuul OSS pattern acts as a gateway, applying authentication, security, monitoring, dynamic throttling, and static response handling through filters before requests reach backend services, with load shedding and capacity allocation.

Enable a circuit breaker and implement a default fallback in Hystrix to return a default book object when a fault occurs, to handle white label errors.

Learn how to route requests to a bookstore producer service through the Zuul API gateway, implement simple filters, and observe pre- and post-request behavior.

Explore non-blocking, asynchronous request processing: a thread pool delegates incoming requests, immediately processes others, and uses the callback function to deliver responses when the work completes.

Master Mono and Flux in Spring's reactive streams, detailing publisher and subscriber roles and back pressure. Learn how Mono emits zero or one element and Flux emits zero to many.

Discover how to route multiple services with Spring Cloud Gateway by building two hello services on ports 888 and 1889, each with a rest controller mapped to hello1 and hello2.

Configure the gateway by defining a bean method to add a request header and a response header. Read the request header in the hello service and verify flow with Postman.

Create a custom gateway filter by extending AbstractGatewayFilterFactory, add a static config class, and implement a pre and post filter via a lambda, chaining filters for a gateway application.

Run the custom filter to observe how it prints the pre filter and the second service method invoked through the gateway.

Create a global filter for all gateway services by returning a global filter method that accepts exchange and chain, and observe the first and second global filter messages.

Create and sequence global filters to process requests in Spring Boot microservices, demonstrating a first global filter followed by a second global filter message.

Demonstrates how a required parameter defaults when missing and prints the given value when present, illustrating resilience in application behavior.