DemoR2dbcApplication.kt

package com.example.demor2dbc

import kotlinx.coroutines.flow.Flow
import org.springframework.beans.factory.InitializingBean
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.data.r2dbc.repository.config.EnableR2dbcRepositories
import org.springframework.data.repository.kotlin.CoroutineCrudRepository
import org.springframework.stereotype.Service

@SpringBootApplication
@EnableR2dbcRepositories
class MissedEventsStreamerApplication

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

interface EventRepository : CoroutineCrudRepository<AppEventEntity<*>, Long> {
	fun findAllByStatus(status: EventStatus): Flow<AppEventEntity<*>>
}

data class AppEventEntity<T>(val id: Long, val status: EventStatus) {
}

@Service
class EventStreamer(private val repository: EventRepository):InitializingBean{
	override fun afterPropertiesSet() {
		println(repository)
	}

}

EventStatus.java

/*
 * Copyright 2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.example.demor2dbc;

public enum EventStatus {
	Hello, World
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.3.3.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>demo-r2dbc</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>demo-r2dbc</name>
	<description>Demo project for Spring Boot</description>

	<properties>
		<java.version>1.8</java.version>
		<kotlin.version>1.3.72</kotlin.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-r2dbc</artifactId>
		</dependency>
		<dependency>
			<groupId>io.projectreactor.kotlin</groupId>
			<artifactId>reactor-kotlin-extensions</artifactId>
		</dependency>
		<dependency>
			<groupId>org.jetbrains.kotlin</groupId>
			<artifactId>kotlin-reflect</artifactId>
		</dependency>
		<dependency>
			<groupId>org.jetbrains.kotlin</groupId>
			<artifactId>kotlin-stdlib-jdk8</artifactId>
		</dependency>
		<dependency>
			<groupId>org.jetbrains.kotlinx</groupId>
			<artifactId>kotlinx-coroutines-reactor</artifactId>
		</dependency>

		<dependency>
			<groupId>io.r2dbc</groupId>
			<artifactId>r2dbc-h2</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
			<exclusions>
				<exclusion>
					<groupId>org.junit.vintage</groupId>
					<artifactId>junit-vintage-engine</artifactId>
				</exclusion>
			</exclusions>
		</dependency>
		<dependency>
			<groupId>io.projectreactor</groupId>
			<artifactId>reactor-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
		<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
			<plugin>
				<groupId>org.jetbrains.kotlin</groupId>
				<artifactId>kotlin-maven-plugin</artifactId>
				<configuration>
					<args>
						<arg>-Xjsr305=strict</arg>
					</args>
					<compilerPlugins>
						<plugin>spring</plugin>
					</compilerPlugins>
				</configuration>
				<dependencies>
					<dependency>
						<groupId>org.jetbrains.kotlin</groupId>
						<artifactId>kotlin-maven-allopen</artifactId>
						<version>${kotlin.version}</version>
					</dependency>
				</dependencies>
			</plugin>
		</plugins>
	</build>

</project>