SpirngBoot整合redis做缓存Demo

2023-02-22 80

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简介： SpirngBoot整合redis做缓存Demo

环境准备

下载

项目代码

Demoo: SSM,SpringBoot or other demo - Gitee.com

redis可视化工具RedisDesktopManager下载

链接：https://pan.baidu.com/s/1e3hVvR5du4Ullv9InjqdSw

提取码：yq07

复制这段内容后打开百度网盘手机App，操作更方便哦

SpringBoot 整合MyBatis

redis环境准备

环境搭建

测试连接

<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
    <dependency>
      <groupId>redis.clients</groupId>
      <artifactId>jedis</artifactId>
      <version>2.9.0</version>
    </dependency>

package com.imooc.demo;
import redis.clients.jedis.Jedis;
public class MyRedis {
  public static void main(String args[]) {
    // 连接redis服务
    Jedis jedis = new Jedis("47.105.132.96", 6379);
    //jedis.auth("123456");  //如果redis有设置密码
    // 查看服务是否运行
    System.out.println("Server is running: " + jedis.ping());
    String name=jedis.get("name");
    System.out.println(name); 
  }
}

整合redis

注意

项目在上面SpringBoot整合MyBatis的基础上修改的

pom.xml

<dependencies>
    <!-- https://mvnrepository.com/artifact/log4j/log4j -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
    <!-- druid -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.18</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>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>1.3.4</version>
    </dependency>
    <!-- <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-devtools</artifactId>
      <scope>runtime</scope>
      <optional>true</optional>
    </dependency> -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <scope>runtime</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

application.properties

添加redis的访问ip地址,我的redis没有密码

######################################
###redis
######################################
spring.redis.host=47.105.132.96

redis配置类

作用：使数据存入redis以json方法存储

package com.example.demo.config;
import java.net.UnknownHostException;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import com.example.demo.entity.User;
@Configuration
public class RedisConfig {
  /**
   * 为 User类添加RedisSerializer 序列号器规则，使其存的方式为JSON
   */
  @Bean
  public RedisTemplate<Object, User> userRedisTemplate(RedisConnectionFactory redisConnectionFactory)
      throws UnknownHostException {
    RedisTemplate<Object, User> template = new RedisTemplate<Object, User>();
    template.setConnectionFactory(redisConnectionFactory);
    Jackson2JsonRedisSerializer<User> serializer = new Jackson2JsonRedisSerializer<>(User.class);
    template.setDefaultSerializer(serializer);
    return template;
  }
  @Bean
  public RedisCacheManager userCacheManager(RedisTemplate<Object, User> userRedisTemplate) {
    RedisCacheManager cacheManager = new RedisCacheManager(userRedisTemplate);
    cacheManager.setUsePrefix(true);
    return cacheManager;
  }
}

service层（敲黑板）（敲黑板）（敲黑板）

@CacheConfig

@Cacheable(value = "user", key = "#id")

@CachePut(value = "user", key = "#user.id")

@CacheEvict(value = "user", key = "#id")

1）@CacheConfig里的cacheNames属性和其余3个注解中的value属性一样，都是代表下图中的上面箭头

2）@Cacheable @CachePut @CacheEvict 里的key属性设置存缓存中的数据的 key，如下图中的第二个箭头，

如果没有指定key,默认为key为方法的参数，value为方法返回的值，我们要设置key为user的id,这里面有语法，自己注意一下

package com.example.demo.service;
import java.util.Date;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheConfig;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import com.example.demo.dao.UserMapper;
import com.example.demo.entity.User;
/**
 *  (1)如果在类上加上下面注解
 *  @CacheConfig(cacheNames="user")
 *  则所有方法中@Cacheable，@CachePut，@CacheEvict  的（value = "user"）可以省略
 *  (2)(cacheManager="userCacheManager") 有多个cacheManager告诉当前service用哪个cacheManager
 */
@CacheConfig(cacheManager="userCacheManager")
@Service
public class UserService {
  @Autowired
  private UserMapper userMapper;
  @Cacheable(value = "user", key = "#id")
  public User getUser(Integer id) {
    System.out.println("查询：" + id);
    User user = userMapper.selectByPrimaryKey(id);
    return user;
  }
  /*
   * @CachePut （1）先调用方法 （2）再缓存数据 
   * 注意：@CachePut(value="user")
   */
  @CachePut(value = "user", key = "#user.id")
  public User updateUser(User user) {
    user.setName(new Date().toString());
    System.out.println("修改：" + user.getId());
    // dao.update(user);
    return user;
  }
  /*
   * @CacheEvict  : 清除缓存
   */
  @CacheEvict(value = "user", key = "#id")
  public void deleteUser(Integer id) {
    System.out.println("delete :"+id);
    //dao.delete(id);
  }
}

控制层

package com.example.demo.controller;
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheConfig;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.example.demo.dao.UserMapper;
import com.example.demo.entity.User;
import com.example.demo.service.UserService;
@RestController
public class UserController {
  @Autowired
  private UserService userService;
  @GetMapping("/user/{id}")
  public User selectUser(@PathVariable("id") int id) {
    User user = userService.getUser(id);
    return user;
  }
  @GetMapping("/updateuser/{id}")
  public String updateUser(@PathVariable("id") int id) {
    //根据id修改user，没查数据库
    User user=new User();
    user.setId(id);
    user.setName("1");
    user.setPassword("1");
    user.setSign(1);
    userService.updateUser(user);
    return "success";
  }
  @GetMapping("/deleteuser/{id}")
  public String deleteUser(@PathVariable("id") int id) {
    userService.deleteUser(id);
    return "success";
  }
}

启动类

添加 @EnableCaching,开启缓存功能

@SpringBootApplication 
@EnableCaching
public class SpringBootCacheApplication {
  public static void main(String[] args) {
    SpringApplication.run(SpringBootCacheApplication.class, args);
  }
}

测试(按照下面顺序访问下面url)

1) http://localhost:8080/user/1

查询user,发送SQL,把key为1的数据放在redis中

2)http://localhost:8080/user/1

查询user,不发送SQL,甚至不走service.selectUser()方法

3)http://localhost:8080/user/2

查询user,发送SQL,把key为2的数据放在redis中

4)http://localhost:8080/updateuser/1

修改id为1的user（上面的修改代码没有连接数据库，直接写死，重点测试缓存），redis中的key为user:1的值修改为新的数据

5) http://localhost:8080/user/1

查询user,不发送SQL,查询到修改后的新数据

6)http://localhost:8080/deleteuser/1

删除缓存中，即redis中key为user:1的数据

7) http://localhost:8080/user/1