Spring boot sample app with API first approach. Integrates Open API Generator to generate API interfaces and Domain models.

Gradle Multimodule project. All directories at level 1 are gradle modules.

.
├── api  // controllers
│   └── src
│       ├── main
│       │   ├── java
│       │   ├── resources
│       │   └── spec // openAPI spec. here
│       └── test
│           ├── java
│           └── resources
├── app
│   └── src
│       ├── main
│       │   ├── java
│       │   └── resources
│       └── test
│           ├── java
│           └── resources
├── config
│   └── src
│       ├── main
│       │   ├── java
│       │   └── resources
│       └── test
│           ├── java
│           └── resources
├── dao
│   └── src
│       ├── main
│       │   ├── java
│       │   └── resources
│       └── test
│           ├── java
│           └── resources
├── entities
│   └── src
│       ├── main
│       │   ├── java
│       │   └── resources
│       └── test
│           ├── java
│           └── resources
└── service  // bussiness logic
    └── src
        ├── main
        │   ├── java
        │   └── resources
        └── test
            ├── java
            └── resources

• OpenAPI generator gradle plugin is integrated in :api gradle module
• Edit Open API spec in :api/src/main/spec folder and execute codegen gradle task
• Interfaces and models are generated at :api/build/src/main/java
• Open API spec is written for two APIs, Todo Entries and Users in separate yaml files. Models are shared between the two APIs.
• Two separate gradle tasks exists to generate the Todo (generateTodoApi) and User (generateUserApi) APIs.
• The above tasks are combined using a single codegen task.

• Swagger UI is available at http://localhost:8083/swagger-ui.html, via `io.springfox:springfox-swagger-ui'
• Swagger API docs at http://localhost:8083/v2/api-docs
• Swagger Docket config and API info is configured at net.ripper.todoapp.api.config.SwaggerConfigurer
• Tags are used to group APIs. an additional `@Api(tags=aTag)' is needed on the Controller implementation for correct grouping.

• Install Flyway cli from http://flywaydb.org
• Change directory to :db and run flyway -configFiles=flyway-{env}.conf migrate to apply migrations in :db\sql folder
• Refer flyway documentation on how to create new migrations.

• Use start-sonar.sh script to start a local sonar instance at port 9001
• Add systemProp.sonar.host.url=http://localhost:9001 to ~/.gradle/gradle.properties
• Run gradle task test followed by sonarqube
• Open sonar UI running at http://localhost:9001 to see code quality results

• Nullable fields in OpenAPI schema are wrapped in JsonNullable
• Fields in JSON can be in 3 states
  • Absent (i.e. missing in the request)
  • Present
  • Null (i.e. {"a":null}) In case of PATCH request the Absent field is supposed to retain the current value. Present or explicit Null should update the value.
• Serialization/Deserialization of JsonNullable, Jackson ObjectMapper is configured in net.ripper.todoapp.api.config.JacksonObjectMapperConfigurer
• Hibernate needs a custom ValueExtractor to extract values and apply constraints. It is configured in net.ripper.todoapp.api.config.ValidationConfigurer

• JWT security
• Unit Tests and Integration tests separation
• Custom spring templates for OpenAPI generator
• Config module implementation
• Complete Docker config
• Add Caching
• Integrate Jacoco or sonar for code quality reports
• Git hooks to format code before code