SpringBoot整合Scala構建Web服務

摘要： 今天我們嘗試Spring Boot整合Scala，並決定建立一個非常簡單的Spring Boot微服務，使用Scala作為程式語言進行編碼構建。 建立專案 初始化專案 mvn archetype:generate -DgroupId=com.edurt.ssi -D...

今天我們嘗試Spring Boot整合Scala，並決定建立一個非常簡單的Spring Boot微服務，使用Scala作為程式語言進行編碼構建。

建立專案

• 初始化專案

mvn archetype:generate -DgroupId=com.edurt.ssi -DartifactId=springboot-scala-integration -DarchetypeArtifactId=maven-archetype-quickstart -Dversion=1.0.0 -DinteractiveMode=false

• 修改pom.xml增加java和scala的支援

<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 http://maven.apache.org/maven-v4_0_0.xsd">

<modelVersion>4.0.0</modelVersion>
<groupId>com.edurt.ssi</groupId>
<artifactId>springboot-scala-integration</artifactId>
<packaging>jar</packaging>
<version>1.0.0</version>

<name>springboot-scala-integration</name>
<description>SpringBoot Scala Integration is a open source springboot, scala 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>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<!-- dependency config -->
<dependency.scala.version>2.12.1</dependency.scala.version>
<!-- plugin config -->
<plugin.maven.scala.version>3.1.3</plugin.maven.scala.version>
</properties>

<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${dependency.scala.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>

<build>
<sourceDirectory>${project.basedir}/src/main/scala</sourceDirectory>
<testSourceDirectory>${project.basedir}/src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>${plugin.maven.scala.version}</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

</project>

• 一個簡單的應用類

package com.edurt.ssi

import org.springframework.boot.SpringApplication
import org.springframework.boot.autoconfigure.SpringBootApplication

@SpringBootApplication
class SpringBootScalaIntegration

object SpringBootScalaIntegration extends App{

SpringApplication.run(classOf[SpringBootScalaIntegration])

}

新增Rest API介面功能

• 建立一個HelloController Rest API介面,我們只提供一個簡單的get請求獲取hello,scala輸出資訊

package com.edurt.ssi.controller

import org.springframework.web.bind.annotation.{GetMapping, RestController}

@RestController
class HelloController {

@GetMapping(value = Array("hello"))
def hello(): String = {
return "hello,scala"
}

}

• 修改SpringBootScalaIntegration檔案增加以下設定掃描路徑

@ComponentScan(value = Array(
"com.edurt.ssi.controller"
))

新增頁面功能

• 修改pom.xml檔案增加以下頁面依賴

<!-- mustache -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mustache</artifactId>
</dependency>

• 修改SpringBootScalaIntegration檔案增加以下設定掃描路徑ComponentScan的value欄位中

"com.edurt.ssi.view"

• 在src/main/resources路徑下建立templates 資料夾
• 在templates資料夾下建立一個名為hello.mustache 的頁面檔案

<h1>Hello, Scala</h1>

• 建立頁面轉換器HelloView

package com.edurt.ssi.view

import org.springframework.stereotype.Controller
import org.springframework.web.bind.annotation.GetMapping

@Controller
class HelloView {

@GetMapping(value = Array("hello_view"))
def helloView: String = {
return "hello";
}

}

• 瀏覽器訪問http://localhost :8080/hello_view即可看到頁面內容

新增資料持久化功能

• 修改pom.xml檔案增加以下依賴(由於測試功能我們使用h2記憶體資料庫)

<!-- 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>

• 修改SpringBootScalaIntegration檔案增加以下設定掃描model路徑

@EntityScan(value = Array(
"com.edurt.ssi.model"
))

• 建立User實體

package com.edurt.ssi.model

import javax.persistence.{Entity, GeneratedValue, Id}

@Entity
class UserModel {

@Id
@GeneratedValue
var id: Long = 0

var name: String = null

}

• 建立UserSupport dao資料庫操作工具類

package com.edurt.ssi.support

import com.edurt.ssi.model.UserModel
import org.springframework.data.repository.PagingAndSortingRepository

trait UserSupport extends PagingAndSortingRepository[UserModel, Long] {

}

• 建立UserService服務類

package com.edurt.ssi.service

import com.edurt.ssi.model.UserModel

trait UserService {

/**
* save model to db
*/
def save(model: UserModel): UserModel;

}

• 建立UserServiceImpl實現類

package com.edurt.ssi.service

import com.edurt.ssi.model.UserModel
import com.edurt.ssi.support.UserSupport
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.stereotype.Service

@Service(value = "userService")
class UserServiceImpl @Autowired() (
val userSupport: UserSupport
) extends UserService {

/**
* save model to db
*/
override def save(model: UserModel): UserModel = {
return this.userSupport.save(model)
}

}

• 建立使用者UserController進行持久化資料

package com.edurt.ssi.controller

import com.edurt.ssi.model.UserModel
import com.edurt.ssi.service.UserService
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.web.bind.annotation.{PathVariable, PostMapping, RequestMapping, RestController}

@RestController
@RequestMapping(value = Array("user"))
class UserController @Autowired()(
val userService: UserService
) {

@PostMapping(value = Array("save/{name}"))
def save(@PathVariable name: String): Long = {
val userModel = {
new UserModel()
}
userModel.name = name
return this.userService.save(userModel).id
}

}

• 使用控制檯視窗執行以下命令儲存資料

curl -X POST http://localhost:8080/user/save/qianmoQ

收到返回結果

表示資料儲存成功

增加資料讀取渲染功能

• 修改UserService增加以下程式碼

/**
 * get all model
 */
def getAll(page: Pageable): Page[UserModel]

• 修改UserServiceImpl增加以下程式碼

/**
* get all model
*/
override def getAll(page: Pageable): Page[UserModel] = {
return this.userSupport.findAll(page)
}

• 修改UserController增加以下程式碼

@GetMapping(value = Array("list"))
def get(): Page[UserModel] = this.userService.getAll(PageRequest.of(0, 10))

• 建立UserView檔案渲染User資料

package com.edurt.ssi.view

import com.edurt.ssi.service.UserService
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.data.domain.PageRequest
import org.springframework.stereotype.Controller
import org.springframework.ui.Model
import org.springframework.web.bind.annotation.GetMapping

@Controller
class UserView @Autowired()(
private val userService: UserService
) {

@GetMapping(value = Array("user_view"))
def helloView(model: Model): String = {
model.addAttribute("users", this.userService.getAll(PageRequest.of(0, 10)))
return "user"
}

}

• 建立user.mustache檔案渲染資料(自行解析返回資料即可)

{{users}}

• 瀏覽器訪問http://localhost :8080/user_view即可看到頁面內容

增加單元功能

• 修改pom.xml檔案增加以下依賴

<!-- 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>

• 建立UserServiceTest檔案進行測試UserService功能

package com.edurt.ssi

import com.edurt.ssi.service.UserService
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
def `get all`() {
println(">> Assert blog page title, content and status code")
val entity = this.userService.getAll(PageRequest.of(0, 1))
print(entity.getTotalPages)
}

}

原始碼地址：GitHub