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Server Application

All server applications use the latest versions of Gradle build tool and Spring Boot.

Microservices Architecture​

Each backend application has only one data source for it and has its own, pretty limited functionality. This is done to make the applications comply with microservices criteria:

  1. Backend applications are small, manageable, self-contained
  2. Can be deployed independently of others
info

More documentation on microservices themselves is available at canonical https://microservices.io/. Also supported by Spring Cloud.

Gradle Build File​

The basic zero setup for a typical project is as follows:

build.gradle
plugins {
    id 'java'    
}

group = 'org.clematis'
version = '1.0.0-SNAPSHOT'

java {
    sourceCompatibility = '17'
}

dependencies {
 //...
}

Gradle version is in the gradle-wrapper.properties file:

distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip
networkTimeout=10000
validateDistributionUrl=true
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists

The minimal project layout is:

/.
 ...
 ├─ gradle
 │ └─ wrapper
 │   ├─ gradle-wrapper.jar
 │   └─ gradle-wrapper.properties
 ... 
 ├─ src
 │ ├─ docs
 │ ├─ main
 │ └─ test
 ...
 build.gradle

Every next chapter will add settings to this file.

Spring Boot Dependencies​

There are some dependencies to be added to the build file:

build.gradle
plugins {
    id 'org.springframework.boot' version '3.4.3'
    id 'io.spring.dependency-management' version '1.1.7'   
}

dependencies {
    annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
    developmentOnly 'org.springframework.boot:spring-boot-devtools'
}

Installing Spring Gradle dependency management plugin will allow autoconfiguration of projects dependencies by applying Spring Maven BOMs to the project's dependencies.

Can be done better

Using Gradle’s native bom support instead can help resolve some issues with security patching.

Groovy Spring Boot Application​

For some applications with Groovy code mixed up with Java code, it may turn out to be more sensible to continue the development of the whole application using Groovy, as in case with Clematis Weather:

@SpringBootApplication
@EntityScan(basePackages = ["jworkspace", "org.clematis.weather"])
@SuppressWarnings(["PMD", "checkstyle:hideutilityclassconstructor"])
@SuppressFBWarnings("EI_EXPOSE_REP")
class WeatherApplication {

    static void main(String[] args) {
        SpringApplication.run(WeatherApplication.class, args)
    }

    @Bean
    ModelMapper modelMapper() {
        return new ModelMapper();
    }
}

There are no significant differences with Java variant, apart from Groovy syntax.