R2DBC 还未完全成熟，现在声明式事务还有点问题，所有文章只简单的写了 kotlin协程 + CRUD
1、依赖管理
第一步 添加相关的 pom 依赖
<?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>2.3.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.sweet</groupId>
<artifactId>ktdemo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>ktdemo</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>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.module</groupId>
<artifactId>jackson-module-kotlin</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>dev.miku</groupId>
<artifactId>r2dbc-mysql</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</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>
2. 数据库配置
R2DBC 的配置和原来的 JDBC配置不同
server.port=9070
spring.r2dbc.url=r2dbc:mysql://localhost:3306/cat1?characterEncoding=UTF-8&useSSL=true
spring.r2dbc.username=root
spring.r2dbc.password=123456
logging.level.com.sweet.ktdemo=DEBUG
logging.level.org.springframework.data.r2dbc=DEBUG
最后一句可以打印出执行的 sql
3. 模型类
data class User(val id: Long, val name: String)
4. Repository
package com.sweet.ktdemo.repository
import com.sweet.ktdemo.model.User
import kotlinx.coroutines.reactive.awaitFirst
import org.springframework.data.r2dbc.core.*
import org.springframework.data.relational.core.query.Criteria
import org.springframework.data.relational.core.query.Update
import org.springframework.stereotype.Service
@Service
class UserRepository(val client: DatabaseClient) {
suspend fun findOne(id: Long): User? =
client.execute("SELECT * FROM t_user where id=:id")
.bind("id", id)
.asType<User>()
.fetch()
.awaitFirst()
suspend fun findAll(): MutableList<User> = client.select().from("t_user")
.asType<User>()
.fetch()
.all()
.collectList()
.awaitFirst()
suspend fun save(user: User) =
client.insert().into<User>().table("t_user")
.using(user)
.await()
suspend fun saveAll(user: List<User>) {
user.forEach { save(it) }
}
suspend fun delete(id: Long) =
client.delete()
.from("t_delete")
.matching(Criteria.where("id").`is`(id))
.fetch().awaitRowsUpdated()
suspend fun update(user: User) =
client.update()
.table("t_user")
.using(Update.update("name", user.name))
.matching(Criteria.where("id").`is`(user.id))
.fetch()
.awaitRowsUpdated()
}
5. Controller
package com.sweet.ktdemo.controller
import com.sweet.ktdemo.model.User
import com.sweet.ktdemo.repository.UserRepository
import org.springframework.web.bind.annotation.*
@RestController
class UserController(val userRepository: UserRepository) {
@GetMapping("/user/{id}")
suspend fun getUser(@PathVariable id: Long): User? =
userRepository.findOne(id)
@GetMapping("/users")
suspend fun getUsers(): List<User> =
userRepository.findAll()
@PostMapping("/users")
suspend fun saveUser(@RequestBody users: List<User>): Unit =
userRepository.saveAll(users)
@DeleteMapping("/users/{id}")
suspend fun deleteUser(@PathVariable id: Long): Int =
userRepository.delete(id)
@PutMapping("/users")
suspend fun updateUser(@RequestBody user: User): Int =
userRepository.update(user)
}
- 测试接口
api-test.http
PUT http://localhost:9070/users
Content-Type: application/json
{
"id" : 1,
"name" : "faef0000Update"
}
###
DELETE http://localhost:9070/users/46
Accept: application/json
###
POST http://localhost:9070/users
Content-Type: application/json
[
{
"id" : 190,
"name" : "Kt01"
},
{
"id" : 20,
"name" : "Kt02"
}
]
###
GET http://localhost:9070/users
Accept: application/json
###
GET http://localhost:9070/user/1
Accept: application/json
### 根据 ID 获取
