Spring Boot with Kotlin Training in Ireland

Note, this course is also available in Java. Or why not combine this with content from our Kotlin Language course.

This course covers all aspects of application development using the Spring family of frameworks. By the end of the delivery delegates will be able to create and customise projects via the Spring Initializr, assemble trees of components via Dependency Injection and AOP, write RESTful services using MVC and WebFlux and access databases using Spring Data. They will also be able to add metrics via Actuator and basic authentication via Spring Security.

Agile development will be continuously empathised during the delivery, with delegates writing tests for their components via both the standard JUnit extensions and the Spring MVC test framework. The course is fully up to date with the new features introduced in Spring 5 and Spring Boot 2 including support for Java 9 types and the Kotlin language.

Delegates must be confident Kotlin developers - the course can be extended with a content from out Kotlin language course to give a complete package. They should also have a basic understanding of the architecture of RESTful services and Single Page Applications.

• Write RESTful services in Kotlin via Spring Boot, MVC and WebFlux
• Write unit tests for Spring including using automatic mock injection
• Use Spring Boot starters for data access and security
• Leverage Kotlin to simplify building Spring Boot applications

Introduction to Spring

• Weaknesses in the original JEE architecture
• Why Spring arose as a cure for the maladies of JEE
• Configuring Spring via XML, YAML, Groovy and Kotlin
• How to choose between the configuration options
• Springs growth from library to framework to ecosystem
• Choosing between the Spring platform and JEE8

Annotation Based Dependency Injection in Spring Core

• The role of the ApplicationContext in Spring DI
• Different ways of providing ‘bean wiring’ to the context object
• Understanding scopes and selecting the correct scope for a bean
• Using @Autowired to perform autowiring by type
• Using @Autowired and @Qualifier for autowiring by name
• Using @Resource as an alternative means of autowiring by name
• Declaring beans using @Component, @Service and @Controller
• Creating bean provider methods via @Configuration classes
• A detailed introduction to Spring Expression Language (Spring EL)
• Populating fields via Spring EL using @Value

Other Forms of Dependency Injection in Spring Core

• The XML based Bean Description Language and Schema Extensions
• The Groovy and Kotlin based Domain Specific Languages
• Support for standard properties files and YAML

Unit Testing Spring Beans

• How a DI container aids unit and integration testing
• Configuring the Spring specific test runner for JUnit
• Injecting dependencies into JUnit tests via Spring
• Creating configurations for different testing scenarios
• Combining mocking frameworks like Mockito with Spring

Introducing Aspect Oriented Development

• The notion of cross-cutting concerns (aka Aspects)
• Key terms (Aspects, Advice, Pointcuts, Weaving etc…)
• A detailed guide to AspectJ Pointcut Expressions
• Support for AOP in Spring Core via auto-proxying
• Why only method calls can be intercepted in Spring
• Declaring Advice and Pointcuts using annotations
• Understanding the five different kinds of advice
• How AOP is used within Spring Security and Transactions

Introduction to Spring Boot

• The need for a meta-framework to manage Spring itself
• Creating Spring Boot projects via the ‘Spring Initializr’
• How Spring Boot configures other parts of Spring as modules
• Customizing the Maven / Gradle build file to manage dependencies
• Options for overriding the default configurations in Spring Boot
• Building and testing command line applications in Spring Boot

Using Spring MVC within Spring Boot

• How MVC evolved from a Web Framework to a Microservices Platform
• MVC Design (Dispatcher Servlet, Handler Mappings and View Resolvers)
• Registering controllers via annotations and component scanning
• The difference between @Controller and @RestController
• Deploying MVC Apps as Microservices via Spring Boot and Cloud Services
• Overriding the default configurations and registering JEE components

Basic Configuration of Spring Controllers

• Associating controller beans with URL patterns
• Mapping methods to HTTP verbs (GET, POST, PUT etc…)
• Triggering methods based on parameters and headers
• Passing objects from the Servlet API into methods
• Injecting individual parameters and populating JavaBeans
• Injecting information from HTTP headers and cookies
• Using path variables to inject information from the URL
• Marshalling the body of the request into JSON and/or XML
• Customizing XML marshalling via the JAXB annotations
• Cusomizing JSON marshalling via Jackson annotations

Advanced Configuration of Spring Controllers

• Wrapping the response type in ResponseEntity
• Creating ResponseEntity objects via the builder API
• Customizing the response code and manipulating HTTP headers
• Validating input via the JSR-303 Bean Validation annotations
• Registering your own validators for cross-field validations
• Using the Optional type for request routing
• Defining model attributes and exception handler methods
• Redirecting output to server pages via view resolvers
• Configuring Thymeleaf as a sample server page library

Writing Tests and Clients for Spring Controllers

• The spring-test module and TestContext framework
• Creating a Web Application Context within a JUnit test
• Sending requests to controllers via the Dispatcher Servlet
• Using the fluent API to specify requests and check responses
• Writing clients for RESTful Services via the JAX-RS Client API
• Writing clients for RESTful Services via the Spring RestTemplate

Enhancements in Spring 5 and Spring Boot 2

• Support for Functional and Reactive Programming in Spring 5
• The new ‘WebFlux’ model for services in Spring Boot 2
• Creating WebFlux based services via MVC annotations
• Creating WebFlux services fia the functional model
• Using the Kotlin based DSL for functional services

Securing and Monitoring Spring Microservices

• Combining Spring Security with Spring Boot Applications
• Different options for adding authentication to endpoints
• Using Spring Actuator to collect metrics from running services
• Customizing and extending the built in metrics and health checks

Database Access with Spring Data

• The famously intractable ‘Object Relational Mismatch’
• Review of ORM frameworks such as Hibernate and the JPA
• How Spring Data simplifies the creation of repositories
• Customizing and extending your repository components