SpringBoot整合Kotlin构建Web服务
今天我们尝试Spring Boot整合Kotlin，并决定建立一个非常简单的Spring Boot微服务，使用Kotlin作为编程语言进行编码构建。
创建一个简单的Spring Boot应用程序。我会在这里使用maven构建项目：
<?xml version="1.0" encoding="UTF-8"?> <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.edurt.ski</groupId> <artifactId>springboot-kotlin-integration</artifactId> <version>1.0.0</version> <packaging>jar</packaging> <name>springboot kotlin integration</name> <description>SpringBoot Kotlin Integration is a open source springboot, kotlin integration example.</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.3.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <!-- plugin config --> <plugin.maven.kotlin.version>1.2.71</plugin.maven.kotlin.version> </properties> <dependencies> <!-- spring boot --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- kotlin --> <dependency> <groupId>com.fasterxml.jackson.module</groupId> <artifactId>jackson-module-kotlin</artifactId> </dependency> <dependency> <groupId>org.jetbrains.kotlin</groupId> <artifactId>kotlin-stdlib-jdk8</artifactId> </dependency> <dependency> <groupId>org.jetbrains.kotlin</groupId> <artifactId>kotlin-reflect</artifactId> </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> <artifactId>kotlin-maven-plugin</artifactId> <groupId>org.jetbrains.kotlin</groupId> <configuration> <args> <arg>-Xjsr305=strict</arg> </args> <compilerPlugins> <plugin>spring</plugin> <plugin>jpa</plugin> <plugin>all-open</plugin> </compilerPlugins> <pluginOptions> <option>all-open:annotation=javax.persistence.Entity</option> </pluginOptions> </configuration> <dependencies> <dependency> <groupId>org.jetbrains.kotlin</groupId> <artifactId>kotlin-maven-allopen</artifactId> <version>${plugin.maven.kotlin.version}</version> </dependency> <dependency> <groupId>org.jetbrains.kotlin</groupId> <artifactId>kotlin-maven-noarg</artifactId> <version>${plugin.maven.kotlin.version}</version> </dependency> </dependencies> <executions> <execution> <id>kapt</id> <goals> <goal>kapt</goal> </goals> <configuration> <sourceDirs> <sourceDir>src/main/kotlin</sourceDir> </sourceDirs> <annotationProcessorPaths> <annotationProcessorPath> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-configuration-processor</artifactId> <version>${project.parent.version}</version> </annotationProcessorPath> </annotationProcessorPaths> </configuration> </execution> </executions> </plugin> </plugins> </build> </project> 复制代码添加所有必需的依赖项：
kotlin-stdlib-jdk8 kotlin jdk8的lib包
kotlin-reflect kotlin反射包
一个简单的应用类：
package com.edurt.ski import org.springframework.boot.autoconfigure.SpringBootApplication import org.springframework.boot.runApplication @SpringBootApplication class SpringBootKotlinIntegration fun main(args: Array<String>) { runApplication<SpringBootKotlinIntegration>(*args) } 复制代码添加Rest API接口功能
创建一个HelloController Rest API接口,我们只提供一个简单的get请求获取hello,kotlin输出信息:
package com.edurt.ski.controller import org.springframework.web.bind.annotation.GetMapping import org.springframework.web.bind.annotation.RestController @RestController class HelloController { @GetMapping(value = "hello") fun hello(): String { return "hello,kotlin" } } 复制代码修改SpringBootKotlinIntegration文件增加以下设置扫描路径
@ComponentScan(value = [ "com.edurt.ski", "com.edurt.ski.controller" ]) 复制代码
添加页面功能
修改pom.xml文件增加以下页面依赖
<!-- mustache --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-mustache</artifactId> </dependency> 复制代码
在
src/main/resources路径下创建templates文件夹在templates文件夹下创建一个名为
hello.mustache的页面文件
<h1>Hello, Kotlin</h1> 复制代码
创建页面转换器HelloView
package com.edurt.ski.view import org.springframework.stereotype.Controller import org.springframework.ui.Model import org.springframework.web.bind.annotation.GetMapping @Controller class HelloView { @GetMapping(value = "hello_view") fun helloView(model: Model): String { return "hello" } } 复制代码浏览器访问http://localhost:8080/hello_view即可看到页面内容
添加数据持久化功能
修改pom.xml文件增加以下依赖(由于测试功能我们使用h2内存数据库)
<!-- data jpa and db --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>com.h2database</groupId> <artifactId>h2</artifactId> <scope>runtime</scope> </dependency> 复制代码
创建User实体
package com.edurt.ski.model import javax.persistence.Entity import javax.persistence.GeneratedValue import javax.persistence.Id @Entity //class UserModel( // @Id // @GeneratedValue // private var id: Long? = 0, // private var name: String //) class UserModel { @Id @GeneratedValue var id: Long? = 0 get() = field set var name: String? = null get() = field set } 复制代码创建UserSupport dao数据库操作工具类
package com.edurt.ski.support import com.edurt.ski.model.UserModel import org.springframework.data.repository.PagingAndSortingRepository interface UserSupport : PagingAndSortingRepository<UserModel, Long> { } 复制代码创建UserService服务类
package com.edurt.ski.service import com.edurt.ski.model.UserModel interface UserService { /** * save model to db */ fun save(model: UserModel): UserModel } 复制代码创建UserServiceImpl实现类
package com.edurt.ski.service import com.edurt.ski.model.UserModel import com.edurt.ski.support.UserSupport import org.springframework.stereotype.Service @Service(value = "userService") class UserServiceImpl(private val userSupport: UserSupport) : UserService { override fun save(model: UserModel): UserModel { return this.userSupport.save(model) } } 复制代码创建用户UserController进行持久化数据
package com.edurt.ski.controller import com.edurt.ski.model.UserModel import com.edurt.ski.service.UserService import org.springframework.web.bind.annotation.PathVariable import org.springframework.web.bind.annotation.PostMapping import org.springframework.web.bind.annotation.RequestMapping import org.springframework.web.bind.annotation.RestController @RestController @RequestMapping(value = "user") class UserController(private val userService: UserService) { @PostMapping(value = "save/{name}") fun save(@PathVariable name: String): UserModel { val userModel = UserModel() // userModel.id = 1 userModel.name = name return this.userService.save(userModel) } } 复制代码使用控制台窗口执行以下命令保存数据
curl -X POST http://localhost:8080/user/save/qianmoQ 复制代码
收到返回结果
{"id":1,"name":"qianmoQ"} 复制代码表示数据保存成功
增加数据读取渲染功能
修改UserService增加以下代码
/** * get all model */ fun getAll(page: Pageable): Page<UserModel> 复制代码
修改UserServiceImpl增加以下代码
override fun getAll(page: Pageable): Page<UserModel> { return this.userSupport.findAll(page) } 复制代码修改UserController增加以下代码
@GetMapping(value = "list") fun get(): Page<UserModel> = this.userService.getAll(PageRequest(0, 10)) 复制代码
创建UserView文件渲染User数据
package com.edurt.ski.view import com.edurt.ski.service.UserService import org.springframework.data.domain.PageRequest import org.springframework.stereotype.Controller import org.springframework.ui.Model import org.springframework.ui.set import org.springframework.web.bind.annotation.GetMapping @Controller class UserView(private val userService: UserService) { @GetMapping(value = "user_view") fun helloView(model: Model): String { model["users"] = this.userService.getAll(PageRequest(0, 10)) return "user" } } 复制代码创建user.mustache文件渲染数据(自行解析返回数据即可)
{{users}} 复制代码浏览器访问http://localhost:8080/user_view即可看到页面内容
增加单元功能
修改pom.xml文件增加以下依赖
<!-- test --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>junit</groupId> <artifactId>junit</artifactId> </exclusion> <exclusion> <groupId>org.mockito</groupId> <artifactId>mockito-core</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId> <scope>test</scope> </dependency> 复制代码
创建UserServiceTest文件进行测试UserService功能
package com.edurt.ski import com.edurt.ski.service.UserService import org.junit.jupiter.api.AfterAll import org.junit.jupiter.api.Test import org.springframework.beans.factory.annotation.Autowired import org.springframework.boot.test.context.SpringBootTest import org.springframework.data.domain.PageRequest @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT) class UserServiceTest(@Autowired private val userService: UserService) { @Test fun `get all`() { println(">> Assert blog page title, content and status code") val entity = this.userService.getAll(PageRequest(0, 1)) print(entity.totalPages) } }
作者：EdurtIO
链接：https://juejin.cn/post/7170505045711159327