redis缓存在我们的开发中是经常使用到的非关系型数据库，可以用于缓存数据库数据，也可以用于存放session

Redis安装和运行可以点击教程链接详细看一下：教程（我是安装在linux，windows端安装RedisDesktopManager，通过远程lia）

Redis:

        Redis是一个key-value的nosql数据库，先存到内存中，会根据一定的策略持久化到磁盘，即使断电也不会丢失数据，支持的数据类型比较多

Redis项目中的运行过程：

       看图：

Redis使用（注解的方式） 

• @Cacheable
• @CachePut：修改当返回的值可以序列化，或者返回值相同的时候才可以使用
• @CacheEvict：返回值不同时，或者不可以序列化，例如ModelAndView我们就要使用CacheEvict先删除， 然后重新获取缓存

Redis代码进行测试，使用SpringBoo项目

创建项目（SpringBoot项目）

1.1.1

导入pom文件

  <parent>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-parent</artifactId>         <version>2.3.0.RELEASE</version>         <relativePath/> <!-- lookup parent from repository -->  </parent>    <properties>         <java.version>11</java.version>     </properties>      <dependencies>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-data-jpa</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.projectlombok</groupId>             <artifactId>lombok</artifactId>             <optional>true</optional>         </dependency>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-test</artifactId>             <scope>test</scope>             <exclusions>                 <exclusion>                     <groupId>org.junit.vintage</groupId>                     <artifactId>junit-vintage-engine</artifactId>                 </exclusion>             </exclusions>         </dependency>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-web</artifactId>         </dependency>         <dependency>             <groupId>junit</groupId>             <artifactId>junit</artifactId>             <scope>test</scope>         </dependency>     </dependencies> 

1.2.1

创建数据库

 create database ssmIDEA; use ssmIDEA; ​ ​ create table user(   id int primary key auto_increment,   name varchar(20),   age int ); select*from user; -- 测试数据 insert into user(name,age)values("huang",20); insert into user(name,age)values("lin",20);

1.2.2

创建包名

1.3.1

完善实体类代码（User）

 package com.example.demo.domain;  import lombok.Data;  import javax.persistence.Entity; import javax.persistence.Id; import java.io.Serializable;  @Data @Entity public class User implements Serializable {       private static final long serialVersionUID = -3055518357571903443L;     @Id     private Integer id;     private String name;     private Integer age;  } 

1.3.2

完善dao层代码（UserJpa）

 package com.example.demo.dao;  import com.example.demo.domain.User; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.stereotype.Repository;  @Repository("user")     public interface UserJpa extends JpaRepository<User,Integer> { } 

1.3.3

完善service层代码（UserService）

 package com.example.demo.service;  import com.example.demo.domain.User;  import java.util.List;  public interface UserService {     public List<User> list(); } 

1.3.4

完善service层实现类代码（UserserviceImpl）

 package com.example.demo.service.impl;  import com.example.demo.dao.UserJpa; import com.example.demo.domain.User; import com.example.demo.service.UserService;  import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service;  import java.util.List;  @Service public class UserServiceImpl implements UserService {      @Autowired     UserJpa userJpa;      @Override     public List<User> list() {         List<User> all = userJpa.findAll();         return all;     } } 

1.3.5

完善视图层代码（UserController）

 package com.example.demo.controller;  import com.example.demo.dao.UserJpa; import com.example.demo.domain.User; import com.example.demo.service.UserService;  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.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody;  import java.util.List;  @Controller public class UserController {     @Autowired     UserService userService;      @Autowired     UserJpa userJpa;     @RequestMapping("/list")     @ResponseBody     //condition = "#id.length()>3"：id的长度大于3进行缓存     //unless = "#result.size()!=0"返回结果不等于null时缓存，unless代表反    @Cacheable(cacheNames = "list",key = "#id",condition = "#id.length()>3",unless = "#result.size()==null")     @CachePut     @CacheEvict     public List<User> list(@RequestParam("id")String id){         List<User> list = userService.list();         return list;     } } 

1.3.6

完善配置文件代码（application.properties）

  Spring.dataSource.driver-class-name=com.mysql.cj.jdbc.Driver Spring.dataSource.url=jdbc:mysql://localhost:3306/ssmidea?serverTimezone=UTC&characterEncoding=utf-8&useSSL=false Spring.dataSource.username=root Spring.dataSource.password=010126  Spring.jpa:shop-sql:true  Spring.redis.host:192.168.137.237 Spring.redis.port:6379

1.3.7

启动类添加注解@EnableCaching

 package com.example.demo;  import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cache.annotation.EnableCaching;  @SpringBootApplication @EnableCaching public class DemoApplication {      public static void main(String[] args) {         SpringApplication.run(DemoApplication.class, args);     }  } 

1.4.1

启动测试，可以使用Debug进行测试

说明缓存成功

细节问题看注释

原创文章，未经允许禁止盗用

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