KTLN-18: Kotlin Microservice With Spring Boot (#8913)

spring-reactive-kotlin/pom.xml

@@ -5,6 +5,7 @@
     <artifactId>spring-reactive-kotlin</artifactId>
     <name>spring-reactive-kotlin</name>
     <description>Demo project for Spring Boot</description>
+
     <packaging>jar</packaging>
 
     <parent>
@@ -23,6 +24,18 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-webflux</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot.experimental</groupId>
+            <artifactId>spring-boot-starter-data-r2dbc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.r2dbc</groupId>
+            <artifactId>r2dbc-h2</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.module</groupId>
             <artifactId>jackson-module-kotlin</artifactId>
@@ -38,21 +51,95 @@
             <artifactId>reactor-test</artifactId>
             <scope>test</scope>
         </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot.experimental</groupId>
+            <artifactId>spring-boot-test-autoconfigure-r2dbc</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
     </dependencies>
 
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot.experimental</groupId>
+                <artifactId>spring-boot-bom-r2dbc</artifactId>
+                <version>0.1.0.M3</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
     <build>
+        <sourceDirectory>src/main/kotlin</sourceDirectory>
+        <testSourceDirectory>src/test/kotlin</testSourceDirectory>
         <plugins>
             <plugin>
                 <artifactId>kotlin-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>compile</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>compile</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>test-compile</id>
+                        <phase>test-compile</phase>
+                        <goals>
+                            <goal>test-compile</goal>
+                        </goals>
+                    </execution>
+                </executions>
                 <groupId>org.jetbrains.kotlin</groupId>
                 <version>${kotlin.version}</version>
                 <configuration>
                     <args>
                         <arg>-Xjsr305=strict</arg>
                     </args>
+                    <jvmTarget>1.8</jvmTarget>
+                    <compilerPlugins>
+                        <plugin>spring</plugin>
+                        <plugin>jpa</plugin>
+                    </compilerPlugins>
                 </configuration>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.jetbrains.kotlin</groupId>
+                        <artifactId>kotlin-maven-allopen</artifactId>
+                        <version>${kotlin.version}</version>
+                    </dependency>
+                    <dependency>
+                        <groupId>org.jetbrains.kotlin</groupId>
+                        <artifactId>kotlin-maven-noarg</artifactId>
+                        <version>${kotlin.version}</version>
+                    </dependency>
+                </dependencies>
             </plugin>
         </plugins>
     </build>
 
+    <properties>
+        <java.version>1.8</java.version>
+        <kotlin.version>1.3.70</kotlin.version>
+        <boot.dependencies.version>2.2.5.RELEASE</boot.dependencies.version>
+    </properties>
+
+    <repositories>
+        <repository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/milestone</url>
+        </repository>
+    </repositories>
+
+
 </project>

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/HealthTrackerApplication.kt

@@ -0,0 +1,11 @@
+package com.baeldung.bootmicroservice
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+
+@SpringBootApplication
+class HealthTrackerApplication
+
+fun main(args: Array<String>) {
+	runApplication<HealthTrackerApplication>(*args)
+}

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/config/DBConfiguration.kt

@@ -0,0 +1,28 @@
+package com.baeldung.bootmicroservice.config;
+
+import org.springframework.context.annotation.Configuration
+import org.springframework.data.r2dbc.core.DatabaseClient
+
+@Configuration
+class DBConfiguration(db: DatabaseClient) {
+    init {
+        val initDb = db.execute {
+            """ CREATE TABLE IF NOT EXISTS profile (
+                    id SERIAL PRIMARY KEY,
+                    first_name VARCHAR(20) NOT NULL,
+                    last_name VARCHAR(20) NOT NULL,
+                    birth_date DATE NOT NULL
+                );
+                CREATE TABLE IF NOT EXISTS health_record(
+                    id SERIAL PRIMARY KEY,
+                    profile_id LONG NOT NULL,
+                    temperature DECIMAL NOT NULL,
+                    blood_pressure DECIMAL NOT NULL,
+                    heart_rate DECIMAL,
+                    date DATE NOT NULL
+                );
+            """
+        }
+        initDb.then().subscribe()
+    }
+}

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/controller/HealthRecordController.kt

@@ -0,0 +1,44 @@
+package com.baeldung.bootmicroservice.controller
+
+import com.baeldung.bootmicroservice.model.AverageHealthStatus
+import com.baeldung.bootmicroservice.model.HealthRecord
+import com.baeldung.bootmicroservice.repository.HealthRecordRepository
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RestController
+import reactor.core.publisher.Mono
+
+@RestController
+class HealthRecordController(val repository: HealthRecordRepository) {
+
+    @PostMapping("/health/{profileId}/record")
+    fun storeHealthRecord(@PathVariable("profileId") profileId: Long, @RequestBody record: HealthRecord): Mono<HealthRecord> =
+            repository.save(HealthRecord(null
+                    , profileId
+                    , record.temperature
+                    , record.bloodPressure
+                    , record.heartRate
+                    , record.date))
+
+    @GetMapping("/health/{profileId}/avg")
+    fun fetchHealthRecordAverage(@PathVariable("profileId") profileId: Long): Mono<AverageHealthStatus> =
+            repository.findByProfileId(profileId)
+                    .reduce(
+                            AverageHealthStatus(0, 0.0, 0.0, 0.0)
+                            , { s, r ->
+                        AverageHealthStatus(s.cnt + 1
+                                , s.temperature + r.temperature
+                                , s.bloodPressure + r.bloodPressure
+                                , s.heartRate + r.heartRate
+                        )
+                    }
+                    ).map { s ->
+                        AverageHealthStatus(s.cnt
+                                , if (s.cnt != 0) s.temperature / s.cnt else 0.0
+                                , if (s.cnt != 0) s.bloodPressure / s.cnt else 0.0
+                                , if (s.cnt != 0) s.heartRate / s.cnt else 0.0)
+                    }
+
+}

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/controller/ProfileController.kt

@@ -0,0 +1,15 @@
+package com.baeldung.bootmicroservice.controller
+
+import com.baeldung.bootmicroservice.model.Profile
+import com.baeldung.bootmicroservice.repository.ProfileRepository
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RestController
+import reactor.core.publisher.Mono
+
+@RestController
+class ProfileController(val repository: ProfileRepository) {
+
+    @PostMapping("/profile")
+    fun save(@RequestBody profile: Profile): Mono<Profile> = repository.save(profile)
+}

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/model/AverageHealthStatus.kt

@@ -0,0 +1,3 @@
+package com.baeldung.bootmicroservice.model;
+
+class AverageHealthStatus(var cnt: Int, var temperature: Double, var bloodPressure: Double, var heartRate: Double)

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/model/HealthRecord.kt

@@ -0,0 +1,8 @@
+package com.baeldung.bootmicroservice.model
+
+import org.springframework.data.annotation.Id
+import org.springframework.data.relational.core.mapping.Table
+import java.time.LocalDate
+
+@Table
+data class HealthRecord(@Id var id: Long?, var profileId: Long?, var temperature: Double, var bloodPressure: Double, var heartRate: Double, var date: LocalDate)

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/model/Profile.kt

@@ -0,0 +1,8 @@
+package com.baeldung.bootmicroservice.model
+
+import org.springframework.data.annotation.Id
+import org.springframework.data.relational.core.mapping.Table
+import java.time.LocalDateTime
+
+@Table
+data class Profile(@Id var id:Long?, var firstName : String, var lastName : String, var birthDate: LocalDateTime)

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/repository/HealthRecordRepository.kt

@@ -0,0 +1,13 @@
+package com.baeldung.bootmicroservice.repository
+
+import com.baeldung.bootmicroservice.model.HealthRecord
+import org.springframework.data.r2dbc.repository.Query
+import org.springframework.data.repository.reactive.ReactiveCrudRepository
+import org.springframework.stereotype.Repository
+import reactor.core.publisher.Flux
+
+@Repository
+interface HealthRecordRepository: ReactiveCrudRepository<HealthRecord, Long> {
+    @Query("select p.* from health_record p where p.profile_id = :profileId ")
+    fun findByProfileId(profileId: Long): Flux<HealthRecord>
+}

spring-reactive-kotlin/src/main/kotlin/com/baeldung/bootmicroservice/repository/ProfileRepository.kt

@@ -0,0 +1,8 @@
+package com.baeldung.bootmicroservice.repository
+
+import com.baeldung.bootmicroservice.model.Profile
+import org.springframework.data.repository.reactive.ReactiveCrudRepository
+import org.springframework.stereotype.Repository
+
+@Repository
+interface ProfileRepository: ReactiveCrudRepository<Profile, Long>

spring-reactive-kotlin/src/main/resources/application.yml

@@ -0,0 +1 @@
+management.endpoints.web.exposure.include: health,metrics

spring-reactive-kotlin/src/test/kotlin/com/baeldung/bootmicroservice/controller/ProfileControllerTest.kt

@@ -0,0 +1,51 @@
+package com.baeldung.bootmicroservice.controller;
+
+import com.baeldung.bootmicroservice.model.Profile
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.http.MediaType
+import org.springframework.test.web.reactive.server.WebTestClient
+import java.time.LocalDateTime
+
+@SpringBootTest
+class ProfileControllerTest {
+    @Autowired
+    lateinit var controller: ProfileController
+
+    @Autowired
+    lateinit var mapper:  ObjectMapper ;
+
+    lateinit var client: WebTestClient
+    lateinit var profile: String
+
+    @BeforeEach
+    fun setup() {
+        client = WebTestClient.bindToController(controller).build()
+        profile = mapper.writeValueAsString(Profile(null, "kotlin", "reactive", LocalDateTime.now()))
+    }
+
+    @Test
+    fun whenRequestProfile_thenStatusShouldBeOk() {
+        client.post()
+                .uri("/profile")
+                .contentType(MediaType.APPLICATION_JSON)
+                .bodyValue(profile)
+                .exchange()
+                .expectStatus().isOk
+    }
+
+    @Test
+    fun whenRequestProfile_thenIdShouldBeNotNull() {
+        client.post()
+                .uri("/profile")
+                .contentType(MediaType.APPLICATION_JSON)
+                .bodyValue(profile)
+                .exchange()
+                .expectBody()
+                .jsonPath("$.id")
+                .isNotEmpty
+    }
+}