苍穹外卖之SpringCache在项目中的应用场景

SpringCache

参考视频或文章：

• https://juejin.cn/post/7507548342508371983

一、技术介绍

1.概述

• SpringCache是Spring框架提供的一套声明式缓存抽象层（只提供接口，不提供实现），通过在方法上添加注解简化缓存操作，无需手动编写缓存逻辑。
• SpringCache支持多种缓存实现，如Caffeine、Redis、EhCache等等，并统一了缓存访问的API。

2.核心特点

• 基于注解的声明式缓存
• 支持SpEL(Spring Expression Language)表达式
• 自动与Spring生态集成
• 支持条件缓存

3.常用缓存注解

二、项目应用

涉及到的文件如下：

sky-take-out:pom.xmlsky-server:pom.xmlsrc/main/java/com.sky:SkyApplicationcontroller:admin:SetmealControlleruser:SetmealController

1.导入和Redis和SpringCache的Maven依赖坐标

1.1sky-take-out: pom.xml

<?xml version="1.0" encoding="UTF-8"?><projectxmlns="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/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><artifactId>spring-boot-starter-parent</artifactId><groupId>org.springframework.boot</groupId><version>2.7.3</version></parent><groupId>com.sky</groupId><artifactId>sky-take-out</artifactId><packaging>pom</packaging><version>1.0-SNAPSHOT</version><modules><module>sky-common</module><module>sky-pojo</module><module>sky-server</module></modules><properties><druid>1.2.1</druid></properties><dependencyManagement><dependencies><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>${druid}</version></dependency></dependencies></dependencyManagement></project>

1.2sky-server: pom.xml

<?xml version="1.0" encoding="UTF-8"?><projectxmlns="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/xsd/maven-4.0.0.xsd"><parent><artifactId>sky-take-out</artifactId><groupId>com.sky</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>sky-server</artifactId><dependencies><dependency><groupId>com.sky</groupId><artifactId>sky-common</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>com.sky</groupId><artifactId>sky-pojo</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><scope>compile</scope></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

2.在项目启动类SkyApplication上开启缓存注解功能

@SpringBootApplication@EnableTransactionManagement// 开启注解方式的事务管理@EnableCaching// 开启注解方式的缓存功能publicclassSkyApplication{publicstaticvoidmain(String[]args){SpringApplication.run(SkyApplication.class,args);}}

3.编写user/SetmealController，使用@Cachable更新缓存

/** * 用户端-套餐接口 */@RestController("userSetmealController")@RequestMapping("/user/setmeal")publicclassSetmealController{@AutowiredprivateSetmealServicesetmealService;@AutowiredprivateDishServicedishService;// 根据分类id查询已启用的套餐@GetMapping("/list")@Cacheable(cacheNames="setmeal",key="#categoryId")// key名称：setmeal::{categoryId}publicResult<List<Setmeal>>getByCategoryId(LongcategoryId){List<Setmeal>setmeals=setmealService.getByCategoryId(categoryId);returnResult.success(setmeals);}}

4.编写admin/SetmealController，使用@CacheEvict清除缓存

/** * 套餐管理模块 */@RestController("adminSetmealController")@RequestMapping("/admin/setmeal")publicclassSetmealController{@AutowiredprivateSetmealServicesetmealService;// 新增套餐和对应的菜品@PostMapping@CacheEvict(cacheNames="setmeal",key="#setmealDTO.categoryId")// 清理缓存publicResultsaveWithDish(@RequestBodySetmealDTOsetmealDTO){setmealService.saveWithDish(setmealDTO);returnResult.success();}// 批量删除套餐@DeleteMapping@CacheEvict(cacheNames="setmeal",allEntries=true)// 清理全部缓存publicResultdeleteBatch(@RequestParamList<Long>ids){setmealService.deleteBatch(ids);returnResult.success();}// 修改套餐@PutMapping@CacheEvict(cacheNames="setmeal",allEntries=true)// 清理全部缓存publicResultupdate(@RequestBodySetmealDTOsetmealDTO){setmealService.updateWithDishes(setmealDTO);returnResult.success();}// 起售停售套餐@PostMapping("/status/{status}")@CacheEvict(cacheNames="setmeal",allEntries=true)// 清理全部缓存publicResultchangeStatus(@PathVariableIntegerstatus,Longid){setmealService.changeStatus(status,id);returnResult.success();}}