Pro Spring Boot 3 with Kotlin: In-Depth Guide to Best Practices for Cloud-Native and Microservices Development. 3 Ed

Table of Contents....5 About the Authors....14 About the Technical Reviewer....15 Introduction....16 Part I: Introduction....17 Chapter 1: Spring Boot Quick Start....18 Project: Users App....18 Initial Setup....18 Start @ start.spring.io....19 Testing the Users App Project....29 Running the UserApplicationTests Class....33 Running the Users App Project....34 Why Spring Boot?....40 Spring Boot Features....43 Summary....45 Chapter 2: Spring Boot Internals....46 Requirements to Create a Spring Boot App....46 Project: My Retro App....48 Auto-Configuration....55 @EnableAutoConfiguration, @Enable, and @Conditional* Annotations....59 @EnableAutoConfiguration....59 @Enable....60 @Conditional*....61 Spring Boot Features....63 Custom Banner....65 SpringApplicationBuilder....72 Application Arguments....75 Executable JAR....77 ApplicationRunner, CommandLineRunner, and ApplicationReadyEvent....77 Application Configuration....80 My Retro App and Users App Project Integration....80 Configuration Properties....83 Relaxed Binding....85 Configuration Precedence....86 Changing Defaults....87 Application Profiles....88 Summary....89 Chapter 3: Spring Boot Web Development....90 Spring MVC....90 Spring Boot MVC Auto-Configuration....91 My Retro App Project....93 Adding Dependencies....96 AOP to the Rescue....107 Spring Web Annotated Controllers....110 Testing My Retro App....117 Users App Project....123 Spring Web Functional Endpoints....129 Testing the Users App....134 Spring Boot Web: Overriding Defaults....138 Overriding Default Server Settings....139 JSON Date Format....140 Using a Different Application Container....141 Spring Boot Web Clients....141 Testing the Client....145 Summary....146 Chapter 4: Spring Boot SQL Data Access....147 Spring Boot Features for SQL Databases....147 Spring Framework Data Access....148 JDBC with Spring Boot....149 Users App: Using Spring Boot JDBC....150 Gravatar: Identifying the User....153 Model: enum and record Types....153 JdbcTemplate and RowMapper....155 Adding the Web Controller....158 Adding Users when the App Is Ready....161 Database Initialization....163 Testing the Users App....164 But Wait... What Happened with the Tests?....167 Running the Users App....168 Using PostgreSQL....171 My Retro App: Using Spring Boot JDBC....174 Running the My Retro App....193 But Wait... What... Again?....195 Summary....195 Chapter 5: Spring Data with Spring Boot....197 Spring Data....197 Spring Data JDBC....198 Spring Data JDBC with Spring Boot....199 Users App with Spring Boot and Spring Data JDBC....199 Testing the Users App....211 Running the Users App....214 My Retro App with Spring Boot and Spring Data JDBC....215 Running the My Retro App....222 Spring Data JPA....225 Spring Data JPA with Spring Boot....226 Users App with Spring Boot and Spring Data JPA....226 Testing and Running the Users App....232 My Retro App Using Spring Boot and Spring Data JPA....233 Running the My Retro App....242 Spring Data REST....243 Spring Data REST with Spring Boot....244 Users App Using Spring Boot and Spring Data REST....244 Running the Users App....248 Testing the Users App....256 My Retro App Using Spring Boot and Spring Data REST....260 Run the My Retro App....263 Summary....267 Chapter 6: Spring Data NoSQL with Spring Boot....269 Spring Data MongoDB....269 Spring Data MongoDB with Spring Boot....270 Users App with Spring Data MongoDB and Spring Boot....270 Testing the Users App....278 Running the Users App....281 My Retro App with Spring Data MongoDB Using Spring Boot....283 Running My Retro App....294 Spring Data Redis....299 Spring Data Redis with Spring Boot....300 Users App with Spring Data Redis Using Spring Boot....300 Testing the Users App....307 Running the Users App....310 My Retro App with Spring Data Redis Using Spring Boot....312 Running My Retro App....316 Summary....319 Chapter 7: Spring Boot Reactive....320 Reactive Systems....320 The Reactive Manifesto....320 Project Reactor....322 Mono, an Asynchronous [0|1] Result....322 Flux: An Asynchronous Sequence of [0|N] Items....323 Reactive Web and Data Applications with Spring Boot....323 Users App with Spring Boot Reactive....325 Testing the Users App....335 Running the Users App....338 My Retro App with Spring Boot Reactive....339 Running My Retro App....353 Summary....354 Chapter 8: Spring Boot Testing....355 Spring Testing Framework....355 Spring Boot Testing Framework....357 Testing Web Apps with a Mock Environment....358 Using Mocking and Spying Beans....362 Testcontainers....366 Spring Boot Testing Slices....368 @JsonTest....370 @WebMvcTest....374 @DataJpaTest....379 @WebFluxTest....382 @DataMongoTest....386 Using Testcontainers to Run Your Spring Boot Applications....389 Summary....391 Part II: Spring Cloud Data Flow: Internals....392 Chapter 9: Spring Boot Security....393 Spring Security....393 Spring Security with Spring Boot....396 Adding Security to Users App....397 Users App Web Controller....403 Testing Security in Users App....403 Mocking Security Tests....406 Using Persistence for Security Authentication in Users App....408 Using Custom Persistence for Your Authentication Security....411 Connecting a UI to Users App....415 Users Frontend/Backend: Let’s Give It a Try!....418 Adding Security to My Retro App....422 Unit Testing My Retro App Security for Authorization....435 Putting Everything Together: UI, Users App, and Retro App....440 Adding a Social Login with OAuth2....443 Social Login to Users App....444 Running Users App with Social Login....452 The Spring Authorization Server....455 Getting Started....456 Using the Spring Authentication Server with Users App....461 Running Users App....467 Wait... What About My Retro App?....470 Summary....471 Chapter 10: Messaging with Spring Boot....472 Messaging As a Concept....472 Messaging with Spring Boot....473 Events with Spring Boot....475 Adding Events to Users App....476 JMS with Spring Boot....479 Which Broker Are We Using?....481 Users App with JMS....481 Running Users App....487 Listen for Incoming User Events with JMS....492 Rerunning Users App....494 Using JMS Topics with My Retro App....495 Running My Retro App....502 AMQP with Spring Boot....503 Installing RabbitMQ....503 RabbitMQ/AMQP: Exchanges, Bindings, and Queues....504 Using AMQP with RabbitMQ in Users App....506 Publishing Messages to RabbitMQ....509 Running Users App with RabbitMQ....514 Consuming Messages from RabbitMQ....521 Running Users App with RabbitMQ to Consume Messages....525 Using RabbitMQ in My Retro App to Consume User Events....525 Running My Retro App to Listen for User Events from RabbitMQ....529 WebSockets with Spring Boot....531 Adding WebSockets to Users App....532 Using the WebSockets Client in Users App to Consume Events....536 Running Users App with WebSockets....539 Using WebSockets in My Retro App to Consume Events....540 Running My Retro App Using WebSockets/STOMP....549 RSocket with Spring Boot....550 Using RSocket with Users App with Spring Boot....551 Running Users App with RSocket and Spring Boot....555 Requesting RSocket Messages in My Retro App....555 Running the RSocket Requester in My Retro App with Spring Boot....561 Other Messaging Frameworks....562 Summary....562 Chapter 11: Spring Boot Actuator....563 What Is Spring Boot Actuator?....563 Users App with Spring Boot Actuator....564 /actuator....567 Configuring /Actuator Endpoints....569 Using Spring Profiles for Actuator Endpoints....570 Enabling Actuator Endpoints....571 /actuator/info....571 /actuator/env....576 /actuator/beans....578 /actuator/conditions....579 /actuator/configprops....580 /actuator/heapdump....581 /actuator/threaddump....581 /actuator/mappings....583 /actuator/loggers....585 /actuator/metrics....586 /actuator/shutdown....590 Adding Security....590 /actuator/auditevents....594 Implementing Custom Actuator Endpoints....596 Accessing Custom Endpoints with JMX....601 More Spring Boot Actuator Configuration....607 CORS Support....607 Changing the Server Address, Port, and Base Path....607 Using SSL with Spring Boot Actuator....608 Configuring Endpoints....608 Overview of /actuator/health....609 Health Indicators....611 A Custom Health Indicator for Users App....614 My Retro App with Spring Boot Actuator Observability: Metrics, Logs, and Tracing....618 Adding Observability to My Retro App....618 Adding Custom Metrics and Observations....621 Adding an External Request with the New @HttpExchange....624 Adding Logging Using Grafana Loki....632 Declaring Services in Docker Compose....635 Ready to Run!....639 Observing with Grafana and Prometheus—Metrics, Logs, and Tracing....641 What About External Resources: Memory, CPU, and Storage?....649 Summary....656 Chapter 12: Spring Boot Native and AOT....657 What Is Spring AOT?....657 What Is GraalVM?....659 Benefits of Using GraalVM....659 Examples of Using GraalVM....660 Spring, Spring Boot, and GraalVM....662 AOT Processing in Spring....663 Creating GraalVM Native Apps....665 Creating a Native Users App....665 Creating a Native My Retro App....676 GraalVM Native Images, wait... What?....685 Creating Native Image for Users App....686 Inspecting the User’s Native Image....687 Creating a My Retro App Native Image....688 Inspecting the My Retro Native Image....689 Testing Native Apps and Images....690 AOT Processing with Custom Hints....690 Summary....692 Chapter 13: Spring Cloud with Spring Boot....693 Challenges Addressed by Spring Cloud....693 Microservices....695 Twelve-Factor App Practices and Spring Boot/Spring Cloud Relationship....696 Cloud Development....699 Using Spring Cloud Technologies....701 HashiCorp Consul and Spring Cloud Consul....703 HashiCorp Consul....704 Using HashiCorp Consul....705 Spring Cloud Consul....708 Using Spring Cloud Consul in Users App....710 Running Users App with Spring Consul....716 Reviewing the UserProperties....719 Using a YAML Format Instead of a Key/Value Pair as a Configuration....721 Using Spring Cloud Consul in My Retro App....724 Using OpenFeign in My Retro App....727 Running My Retro App....735 HashiCorp Vault and Spring Cloud Vault....736 HashiCorp Vault....736 Using HashiCorp Vault with Credentials Creation for PostgreSQL....738 Spring Cloud Vault....744 Implementing Credential Generation on the Users Service App Using HashiCorp Vault....746 Running Users App with Vault....748 Fixing Credential Rotation by Adding a Listener....749 Using Spring Cloud Gateway....753 Creating a My Retro Gateway....754 Running the My Retro Gateway....758 More Gateway Features....762 CircuitBreaker Filter....762 Adding the CircuitBreaker Filter to the My Retro Gateway App....763 Integrating the Cloud Environment into Docker Compose....766 Creating Multi-Architecture Images....771 Using a Cloud Platform: Kubernetes....773 Using Kubernetes....775 Prerequisites: Installation....775 Starting Minikube....775 Creating the Postgres Deployment....776 ConfigMap....776 PersistentVolume and PersistentVolumeClaim....776 Deployment....777 Service....779 Installing the Declarations....779 Deploying Microservices in Kubernetes: Users App, My Retro App, and My Retro Gateway App Deployments....780 ClusterRole and ClusterRoleBinding....780 Users Deployment and Service....781 My Retro Deployment and Service....784 My Retro Gateway ConfigMap, Deployment, and Service....786 Access to My Retro Gateway: Using Port-Forward....790 Cleaning Up....790 Summary....791 Chapter 14: Extending Spring Boot....792 Benefits of a Custom Starter....792 Revisiting @Conditional and @Enable....793 Requirements of the Custom Spring Boot Starter....795 Rules and Guidelines for a Custom Spring Boot Starter....797 Creating My Retro Spring Boot Starter....798 Building the myretro-spring-boot-starter Custom Starter....819 Publishing the Custom Starter in GitHub as a Maven Artifact....820 Using the myretro-spring-boot-starter Custom Starter....825 Running Users App with myretro-spring-boot-starter....833 Summary....835 Chapter 15: Spring Boot New Projects....837 Spring Modulith....837 Comparing Spring Modulith with Microservices....837 Choosing the Right Approach....838 Fundamentals....839 Understanding Module Packages in Spring Boot....841 Using Spring Modulith in the My Retro Solution....842 Running the My Retro Solution....854 Spring AI....855 AI Concepts....855 Models....855 Prompts....856 Prompt Templates....857 Embeddings....857 Tokens....858 Teaching AI New Tricks: Beyond the Training Dataset....859 Creating a Chat GPT Client....859 Running the App....862 Summary....862 Appendix A: Spring Boot Migration....863 Migrating Spring Security....863 Using HttpSecurity....863 WebSecurity Configuration....864 LDAP Authentication....865 In-Memory Authentication....866 JDBC Authentication....867 Upgrading to Spring Boot 3....869 Using Configuration Properties Migration....872 Spring Boot Migrator....873 Summary....873 Appendix B: Spring Boot GraphQL....874 What Is GraphQL?....874 Spring for GraphQL....876 Spring for GraphQL and Spring Boot: A Match Made in Developer Heaven....877 Using GraphQL in Users App....878 The Users GraphQL Controller....883 The Users GraphQL Schema....886 Running Users App....890 Using GraphQL in My Retro App....895 Summary....901 Index....902