Spring Cache快速入门教程及案例

谁借莪１个温暖的怀抱￠ 2024-02-05 11:49 15阅读 0赞

## 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：

<table> 
 <thead> 
  <tr> 
   <th><strong>注解</strong></th> 
   <th><strong>说明</strong></th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>@EnableCaching</td> 
   <td>开启缓存注解功能，通常加在启动类上</td> 
  </tr> 
  <tr> 
   <td>@Cacheable</td> 
   <td>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<br>如果没有缓存数据，调用方法并将方法返回值放到缓存中</td> 
  </tr> 
  <tr> 
   <td>@CachePut</td> 
   <td>将方法的返回值放到缓存中</td> 
  </tr> 
  <tr> 
   <td>@CacheEvict</td> 
   <td>将一条或多条数据从缓存中删除</td> 
  </tr> 
 </tbody> 
</table>

## 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
         */
        @Bean
        public 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 {
        
    
        @Autowired
        private 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")
        @GetMapping
        public 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.Driver
          url: jdbc:mysql://localhost:13306/spring_cache_demo?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true
          username: root
          password: root
      redis:
        host: localhost
        port: 6379
        password: 123456
        database: 1
    logging:
      level:
        com:
          itheima:
            mapper: debug
            service: info
            controller: 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>