SpringBoot整合Kotlin构建Web服务的方法示例

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>

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)
}

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"
  }

}

修改springbootkotlinintegration文件增加以下设置扫描路径

@componentscan(value = [
  "com.edurt.ski",
  "com.edurt.ski.controller"
])

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>

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>

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"
  }

}

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>

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

}

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> {

}

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

}

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)
  }

}

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)
  }

}

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

收到返回结果

{"id":1,"name":"qianmoq"}

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>

修改userserviceimpl增加以下代码

override fun getall(page: pageable): page<usermodel> {
  return this.usersupport.findall(page)
}

修改usercontroller增加以下代码

@getmapping(value = "list")
fun get(): page<usermodel> = this.userservice.getall(pagerequest(0, 10))

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"
  }

}

创建user.mustache文件渲染数据(自行解析返回数据即可)

{{users}}

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>

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)
  }

}

源码地址：github

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。