Spring Boot REST API Demo Todo App

Features

• Java 17
• Spring Boot 3
• Spring Web REST API
• Java record DTO
• HTTP PATCH using Java record
• Spring Data JDBC ListCrudRepository
• Spring Data JDBC custom SQL query
• Spring Data JDBC ListQueryByExampleExecutor
• Spring Data JDBC pagination, sort and filter
• Spring Data JDBC Event Listener to log to history table
• Flyway DB migration
• h2 MODE=MySQL file DB for dev and in-memory DB for test
• RFC7807 ProblemDetail RestControllerAdvice using ResponseEntityExceptionHandler
• RFC7807 ProblemDetail i18n custom message in messages.properties
• HTTP Client using @HttpExchange
• Custom properties in application.properties
• unit tests with coverage report

Maven Packages in pom.xml

• org.springframework.boot
  • spring-boot-starter-web
  • spring-boot-starter-webflux
  • spring-boot-starter-validation
  • spring-boot-starter-data-jdbc
  • spring-boot-devtools
  • spring-boot-starter-test
  • spring-boot-starter-security
  • spring-boot-configuration-processor
• com.h2database
• org.flywaydb
• org.springdoc

Quick Start

java -version
# openjdk version "17.0.8.1" 2023-08-22 LTS

mvn --version
# Apache Maven 3.9.4

mvn spring-boot:run

curl http://localhost:8080/todos

• http://localhost:8080/swagger-ui.html
• http://localhost:8080/h2-console
  • JDBC URL: jdbc:h2:file:./target/demodb

Spring Initializr

https://start.spring.io/

• Spring Web
• Spring Data JDBC
• H2 Database
• Flyway Migration
• Spring Boot DevTools

Setup JDK Maven

• https://docs.aws.amazon.com/corretto/latest/corretto-17-ug/downloads-list.html
• https://maven.apache.org/download.cgi

# MacOS .zshrc sample
export JAVA_HOME=`/usr/libexec/java_home -v 17`
export PATH=${JAVA_HOME}/bin:${PATH}
export PATH=~/Downloads/apache-maven-3.9.4/bin:${PATH}

Test

• https://medium.com/@truongbui95/jacoco-code-coverage-with-spring-boot-835af8debc68
• https://sukkiri.jp/technologies/devtools/jacoco/jacoco-with-maven.html
• method naming convention is short form of MethodName_StateUnderTest_ExpectedBehavior
  • https://dzone.com/articles/7-popular-unit-test-naming

mvn clean test site

python -m http.server --directory ./target/site/
# unit tests report at http://localhost:8000/

python -m http.server --directory ./target/site/jacoco/ 3000
# coverage report at http://localhost:3000/

# verify if the coverage is above the minimum for CI
mvn clean verify

DB Migration

• Note: 3 type of DB initialization
  • schema version: Flyway V files
  • reference data: Flyway R file
  • dev mock data: Spring built-in data.sql
    • test specific data: @Sql annotation
• in Dev: auto migration when server started
• in Prod: manual migration by Flyway plugin

export FLYWAY_URL="jdbc:h2:file:./target/demodb;MODE=MySQL;AUTO_SERVER=TRUE"
export FLYWAY_USER=sa
export FLYWAY_PASSWORD=

mvn flyway:info
mvn flyway:migrate
mvn flyway:validate

Upgrade Maven Packages

• check outdated packages
  • https://medium.com/@mlvandijk/keeping-dependencies-up-to-date-with-maven-be8f7fb6441e
• upgrade packages
  • https://kazuhira-r.hatenablog.com/entry/20160528/1464444327

# display dependency updates
mvn versions:display-dependency-updates

# display plugin updates
mvn versions:display-plugin-updates

# update pom.xml as suggested
# c.f. VSCode Redhat Dependency Analytics extension

# show dependency-tree
mvn dependency:tree
mvn dependency:tree -Dincludes=org.slf4j:slf4j-api

# find unused dependencies
mvn dependency:analyze

# upgrade to release (latest stable non-SNAPSHOT)
mvn versions:use-latest-releases
# upgrade to newest possible (includes unstable SNAPSHOT)
mvn versions:use-latest-versions

Reference

• https://spring.io/guides/gs/rest-service/
• https://spring.io/guides/tutorials/rest/
• https://docs.spring.io/spring-data/jdbc/docs/current/reference/html/