seefa / spring-boot-starter

Building Spring Boot application with Gradle plus Kotlin

1-Make a Gradle Project by Kotlin language syntax with IDE

2- Make Project package structure(ir.seefa.sample.project) in src/main/kotlin and src/test/kotlin

• Hint: Be careful about word spelling for packages because Test classes will not able to run SpringBoot Test Runner if Packages or Classes are not match names.

3- add below codes to build.gradle.kts to get Spring Boot dependencies and project features(Project name, Project version, Java plugin, dependencies, Add a task to making JAR file, Java configuration, so on)

 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
     id("org.springframework.boot") version "2.1.6.RELEASE"
     id("io.spring.dependency-management") version "1.0.7.RELEASE"
     kotlin("jvm") version "1.2.71"
     kotlin("plugin.spring") version "1.2.71"
 }
 
 group = "ir.seefa.sample.project"
 version = "1.0-SNAPSHOT"
 java.sourceCompatibility = JavaVersion.VERSION_11
 
 repositories {
     mavenCentral()
 }
 
 dependencies {
     implementation("org.springframework.boot:spring-boot-starter-web")
     implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
     implementation("org.jetbrains.kotlin:kotlin-reflect")
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
     testImplementation("org.springframework.boot:spring-boot-starter-test")
 }
 
 tasks.withType<KotlinCompile> {
     kotlinOptions {
         freeCompilerArgs = listOf("-Xjsr305=strict")
         jvmTarget = "1.8"
     }
 }

• Tips:
  1. import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
  2. plugins -> org.springframework.boot,io.spring.dependency-management,kotlin("jvm"),kotlin("plugin.spring")
  3. apply plugin -> io.spring.dependency-management
  4. Project properties: Group,Version,java.sourceCompatibility
  5. repositories
  6. dependencies implementation -> org.springframework.boot:spring-boot-starter-web,implementation -> com.fasterxml.jackson.module:jackson-module-kotlin,implementation -> org.jetbrains.kotlin:kotlin-reflect,implementation -> org.jetbrains.kotlin:kotlin-stdlib-jdk8,testImplementation -> org.springframework.boot:spring-boot-starter-test
  7. tasks.withType

4- Add SpringBootStarterApplication.kt class to has been made package from Step 2 with following code:

package ir.seefa.sample.project

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication

@SpringBootApplication
class SpringBootStarterApplication

fun main(args: Array<String>) {
	runApplication<SpringBootStarterApplication>(*args)
}

5- Add application.properties file to src/main/resources path for apply application configuration before run such server port as follows:

server.port=9090

6- Add SpringBootStarterApplicationTests class to /src/test/kotlin/[Package_Name] with following codes

package ir.seefa.sample.project

import org.junit.Test
import org.junit.runner.RunWith
import org.springframework.boot.test.context.SpringBootTest
import org.springframework.test.context.junit4.SpringRunner

@RunWith(SpringRunner::class)
@SpringBootTest
class SpringBootStarterApplicationTests {

	@Test
	fun contextLoads() {
	}

}

7- run command gradle in command line

8- run command gradle tasks in command line

9- Build your project with Gradle Wrapper => Run in command line(gradle wrapper --gradle-version 5.4.1)

10- After passing step No.8, we can only run this command to build project(./gradlew build)

11- Run this command will execute our Application(./gradlew run) or Run SpringBootStarterApplication directly.