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Scala是一門多范式的編程語言,一種類似Java的編程語言,設計初衷是實現可伸縮的語言并集成面向對象編程。Scala把Erlang風格的基于actor的并發帶進了JVM,開發者可以利用Scala的actor模型在JVM上設計具伸縮性的并發應用程序,它會自動獲得多核心處理器帶來的優勢,而不必依照復雜的Java線程模型來編寫程序,接下來就介紹一下如何在SpringBoot框架中使用Scala來進行簡單的Web開發,對scala不了解的建議先去學習基礎哦
一、導入依賴
<?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依賴庫--> <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的編譯插件,否則無法進行編譯--> <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>
通過上面我們可以發現,和創建Java版本的SpringBoot項目沒啥不同,只是引入了scala-library這個我們之前沒引入的包,同時增加了對scala編譯的插件
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 # 設置創表引擎為Innodb,不然默認為MyiSam database-platform: org.hibernate.dialect.MySQL5InnoDBDialect swagger: base-package: com.gjing.project.scala.controller title: scala學習的demo
三、創建實體類
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)" }
這塊和我們用java開發沒啥不同,只是@BeanProperty注解會幫我們生成get和set
四、Repository層
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] { /** * 通過用戶名查詢 * @param name 用戶名 * @return Customer */ def findByCustomerName(name:String) : Customer }
這里和JAVA不同的是泛型采用的是[]中括號,這點要注意
五、Service層
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) { /** * 保存用戶 * * @param name 用戶名 */ def saveCustomer(name: String): Unit = { var customer = customerRepository.findByCustomerName(name) if (customer != null) { throw MyServiceException("添加失敗,用戶已存在") } customer = new Customer(name) customerRepository.save(customer) } /** * 分頁查詢 * * @param pageable 分頁對象 * @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) } /** * 更新用戶名 * @param id 用戶id * @param name 用戶名 */ def updateCustomer(id: Integer, name: String): Unit = { val customer = customerRepository.findById(id).orElseThrow(() => MyServiceException("更新失敗,用戶不存在")) customer.setCustomerName(name) customerRepository.saveAndFlush(customer) } /** * 刪除指定用戶 * @param id 用戶id */ def deleteCustomer(id:Integer): Unit = { val customer = customerRepository.findById(id).orElseThrow(() => MyServiceException("刪除失敗,用戶不存在")) customerRepository.delete(customer) } }
有意思的是,在scala中依賴注入是寫在類名上的
六、Controller層
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("用戶的相關功能")) class CustomerController @Resource()(customerService:CustomerService){ @PostMapping(Array("/customer")) @ApiOperation("添加用戶") @ApiImplicitParam(name = "customerName",value = "用戶名",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("分頁查詢") @ApiImplicitParams(Array( new ApiImplicitParam(name = "page",value = "頁數",required = true,dataType = "int",paramType = "query"), new ApiImplicitParam(name = "size",value = "條數",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("更新用戶") @ApiImplicitParams(Array( new ApiImplicitParam(name = "id",value = "用戶ID",required = true,dataType = "int",paramType = "query"), new ApiImplicitParam(name = "name",value = "用戶名",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("刪除用戶") def deleteCustomer(id:Integer): ResponseEntity[String] = { customerService.deleteCustomer(id) ResponseEntity.ok("刪除成功") } }
這樣我們一個簡單的Scala版本的Web項目就寫好啦,只需要啟動就可以試著運行啦,本文的源代碼地址:scala-demo,有任何不清楚的可以在評論區回復哈
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持億速云。
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