Spring Boot with Kotlin Training

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