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1. Spring Cache介绍

Spring Cache提供了一组注解，使开发者能够轻松地在方法上定义缓存行为

Spring Cache抽象了缓存的底层实现，允许开发者选择使用不同的缓存提供者（如 Ehcache、Redis、Caffeine 等）。通过配置相应的缓存管理器，可以方便地切换底层缓存实现，而无需改变应用代码

Spring Cache的maven坐标：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId><version>3.1.5</version>
</dependency>

Spring Cache的常用注解：

注解	说明
@EnableCaching	开启缓存注解功能，通常加在启动类上
@Cacheable	在方法执行前先查询缓存中是否有数据，如果有数据，则直接返回缓存数据 如果没有缓存数据，调用方法并将方法返回值放到缓存中
@CachePut	将方法的返回值放到缓存中
@CacheEvict	将一条或多条数据从缓存中删除

2. Spring Cache入门案例

CacheDemoApplication.java

package com.itheima;import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;@Slf4j
@SpringBootApplication
@EnableCaching
public class CacheDemoApplication {public static void main(String[] args) {SpringApplication.run(CacheDemoApplication.class, args);log.info("项目启动成功...");}
}

WebMvcConfiguration.java

@Configuration
@Slf4j
public class WebMvcConfiguration extends WebMvcConfigurationSupport {/*** 生成接口文档配置** @return*/@Beanpublic Docket docket() {log.info("准备生成接口文档...");ApiInfo apiInfo = new ApiInfoBuilder().title("接口文档").version("2.0").description("接口文档").build();Docket docket = new Docket(DocumentationType.SWAGGER_2).apiInfo(apiInfo).select()//指定生成接口需要扫描的包.apis(RequestHandlerSelectors.basePackage("com.itheima.controller")).paths(PathSelectors.any()).build();return docket;}/*** 设置静态资源映射** @param registry*/protected void addResourceHandlers(ResourceHandlerRegistry registry) {log.info("开始设置静态资源映射...");registry.addResourceHandler("/doc.html").addResourceLocations("classpath:/META-INF/resources/");registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");}
}

User.java

@Data
public class User implements Serializable {private static final long serialVersionUID = 1L;private Long id;private String name;private int age;
}

UserController.java

package com.itheima.controller;import com.itheima.entity.User;
import com.itheima.mapper.UserMapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.web.bind.annotation.*;@RestController
@RequestMapping("/user")
@Slf4j
public class UserController {@Autowiredprivate UserMapper userMapper;@PostMapping@CachePut(cacheNames = "userCache", key = "#user.id")// @CachePut(cacheNames = "userCache", key = "#result.id")// @CachePut(cacheNames = "userCache", key = "#p0.id")// @CachePut(cacheNames = "userCache", key = "#a0.id")// @CachePut(cacheNames = "userCache", key = "#root.args[0].id")public User save(@RequestBody User user){userMapper.insert(user);return user;}@Cacheable(cacheNames = "userCache", key = "#id")@GetMappingpublic User getById(Long id){User user = userMapper.getById(id);return user;}@DeleteMapping@CacheEvict(cacheNames = "userCache", key = "#id")public void deleteById(Long id){userMapper.deleteById(id);}@DeleteMapping("/delAll")@CacheEvict(cacheNames = "userCache", allEntries = true)public void deleteAll(){userMapper.deleteAll();}
}

UserMapper.java

@Mapper
public interface UserMapper {@Insert("insert into user(name,age) values (#{name}, #{age})")@Options(useGeneratedKeys = true, keyProperty = "id")void insert(User user);@Delete("delete from user where id = #{id}")void deleteById(Long id);@Delete("delete from user")void deleteAll();@Select("select * from user where id = #{id}")User getById(Long id);
}

application.yml

server:port: 8888
spring:datasource:druid:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://localhost:13306/spring_cache_demo?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=trueusername: rootpassword: rootredis:host: localhostport: 6379password: 123456database: 1
logging:level:com:itheima:mapper: debugservice: infocontroller: info

pom.xml

<?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 http://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>2.7.3</version><relativePath/></parent><groupId>com.itheima</groupId><artifactId>springcache-demo</artifactId><version>1.0-SNAPSHOT</version><properties><maven.compiler.source>11</maven.compiler.source><maven.compiler.target>11</maven.compiler.target></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><scope>compile</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.20</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.76</version></dependency><dependency><groupId>commons-lang</groupId><artifactId>commons-lang</artifactId><version>2.6</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.2.0</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.1</version></dependency><dependency><groupId>com.github.xiaoymin</groupId><artifactId>knife4j-spring-boot-starter</artifactId><version>3.0.2</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><version>2.7.3</version></plugin></plugins></build>
</project>