Scala是一门多范式的编程语言，一种类似Java的编程语言，设计初衷是实现可伸缩的语言并集成面向对象编程。Scala把Erlang风格的基于actor的并发带进了JVM，开发者可以利用Scala的actor模型在JVM上设计具伸缩性的并发应用程序，它会自动获得多核心处理器带来的优势，而不必依照复杂的Java线程模型来编写程序，接下来就介绍一下如何在SpringBoot框架中使用Scala来进行简单的Web开发，对scala不了解的建议先去学习基础哦
一、导入依赖
<?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>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.gjing.project</groupId>
<artifactId>scala-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>scala-demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!--加入Scala依赖库-->
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>2.13.1</version>
</dependency>
<dependency>
<groupId>cn.gjing</groupId>
<artifactId>tools-starter-swagger</artifactId>
<version>1.3.0</version>
</dependency>
<dependency>
<groupId>cn.gjing</groupId>
<artifactId>tools-common</artifactId>
<version>1.2.7</version>
</dependency>
</dependencies>
<build>
<plugins>
<!--加入Scala的编译插件，否则无法进行编译-->
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<version>2.15.2</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>
通过上面我们可以发现，和创建Java版本的SpringBoot项目没啥不同，只是引入了scala-library这个我们之前没引入的包，同时增加了对scala编译的插件
二、配置YML文件
server:
port: 8080
spring:
application:
name: scala-demo
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/demo?characterEncoding=utf8&useSSL=false
username: root
password: root
type: com.zaxxer.hikari.HikariDataSource
hikari:
maximum-pool-size: 5
minimum-idle: 1
idle-timeout: 30000
connection-timeout: 30000
jpa:
database: mysql
hibernate:
ddl-auto: update
# 设置创表引擎为Innodb，不然默认为MyiSam
database-platform: org.hibernate.dialect.MySQL5InnoDBDialect
swagger:
base-package: com.gjing.project.scala.controller
title: scala学习的demo
三、创建实体类
import javax.persistence._
import scala.beans.BeanProperty
/**
* @author Gjing
**/
@Entity
@Table(name = "scala_customer")
class Customer {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@BeanProperty
var id:Integer = _
@BeanProperty
var customerName:String = _
def this(customerName:String){
this()
this.customerName = customerName
}
override def toString: String = s"Customer($id,$customerName)"
}
这块和我们用java开发没啥不同，只是@BeanProperty注解会帮我们生成get和set
四、Repository层
import com.gjing.project.scala.entity.Customer
import org.springframework.data.jpa.repository.JpaRepository
import org.springframework.stereotype.Repository
/**
* @author Gjing
**/
@Repository
trait CustomerRepository extends JpaRepository[Customer, Integer] {
/**
* 通过用户名查询
* @param name 用户名
* @return Customer
*/
def findByCustomerName(name:String) : Customer
}
这里和JAVA不同的是泛型采用的是[]中括号，这点要注意
五、Service层
import cn.gjing.tools.common.result.PageResult
import com.gjing.project.scala.entity.Customer
import com.gjing.project.scala.exceptions.MyServiceException
import com.gjing.project.scala.repository.CustomerRepository
import javax.annotation.Resource
import org.springframework.data.domain.Pageable
import org.springframework.stereotype.Service
/**
* @author Gjing
**/
@Service
class CustomerService @Resource()(customerRepository: CustomerRepository) {
/**
* 保存用户
*
* @param name 用户名
*/
def saveCustomer(name: String): Unit = {
var customer = customerRepository.findByCustomerName(name)
if (customer != null) {
throw MyServiceException("添加失败，用户已存在")
}
customer = new Customer(name)
customerRepository.save(customer)
}
/**
* 分页查询
*
* @param pageable 分页对象
* @return
*/
def pageCustomer(pageable: Pageable): PageResult[java.util.List[Customer]] = {
val page = customerRepository.findAll(pageable)
return PageResult.of(page.getContent, page.getTotalPages, page.getSize, page.getTotalElements, page.getNumber)
}
/**
* 更新用户名
* @param id 用户id
* @param name 用户名
*/
def updateCustomer(id: Integer, name: String): Unit = {
val customer = customerRepository.findById(id).orElseThrow(() => MyServiceException("更新失败，用户不存在"))
customer.setCustomerName(name)
customerRepository.saveAndFlush(customer)
}
/**
* 删除指定用户
* @param id 用户id
*/
def deleteCustomer(id:Integer): Unit = {
val customer = customerRepository.findById(id).orElseThrow(() => MyServiceException("删除失败，用户不存在"))
customerRepository.delete(customer)
}
}
有意思的是，在scala中依赖注入是写在类名上的
六、Controller层
import cn.gjing.tools.common.annotation.NotEmpty
import cn.gjing.tools.common.result.PageResult
import com.gjing.project.scala.entity.Customer
import com.gjing.project.scala.service.CustomerService
import io.swagger.annotations.{Api, ApiImplicitParam, ApiImplicitParams, ApiOperation}
import javax.annotation.Resource
import org.springframework.data.domain.PageRequest
import org.springframework.http.ResponseEntity
import org.springframework.web.bind.annotation._
/**
* @author Gjing
**/
@RestController
@Api(tags = Array("用户的相关功能"))
class CustomerController @Resource()(customerService:CustomerService){
@PostMapping(Array("/customer"))
@ApiOperation("添加用户")
@ApiImplicitParam(name = "customerName",value = "用户名",dataType = "String",required = true,paramType = "query")
@NotEmpty
def saveCustomer(customerName:String): ResponseEntity[String] ={
customerService.saveCustomer(customerName)
ResponseEntity.ok("添加成功")
}
@GetMapping(Array("/customer_page"))
@ApiOperation("分页查询")
@ApiImplicitParams(Array(
new ApiImplicitParam(name = "page",value = "页数",required = true,dataType = "int",paramType = "query"),
new ApiImplicitParam(name = "size",value = "条数",required = true,dataType = "int",paramType = "query"),
))
def pageCustomer(page:Integer,size:Integer): ResponseEntity[PageResult[java.util.List[Customer]]]={
ResponseEntity.ok(customerService.pageCustomer(PageRequest.of(page, size)))
}
@NotEmpty
@PutMapping(Array("/customer"))
@ApiOperation("更新用户")
@ApiImplicitParams(Array(
new ApiImplicitParam(name = "id",value = "用户ID",required = true,dataType = "int",paramType = "query"),
new ApiImplicitParam(name = "name",value = "用户名",required = true,dataType = "String",paramType = "query")
))
def updateCustomer(id:Integer,name:String): ResponseEntity[String] = {
customerService.updateCustomer(id, name)
ResponseEntity.ok("修改成功")
}
@DeleteMapping(Array("/customer/{id}"))
@ApiOperation("删除用户")
def deleteCustomer(id:Integer): ResponseEntity[String] = {
customerService.deleteCustomer(id)
ResponseEntity.ok("删除成功")
}
}
这样我们一个简单的Scala版本的Web项目就写好啦，只需要启动就可以试着运行啦，本文的源代码地址：scala-demo，有任何不清楚的可以在评论区回复哈
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