名称 |
解释 |
Cache | 缓存接口,定义缓存操作。实现有:RedisCache、EhCacheCache、ConcurrentMapCache等 |
CacheManager | 缓存管理器,管理各种缓存(cache)组件 |
@Cacheable | 主要针对方法配置,能够根据方法的请求参数对其进行缓存 |
@CacheEvict | 清空缓存 |
@CachePut | 保证方法被调用,又希望结果被缓存与@Cacheable区别在于是否每次都调用方法,常用于更新 |
@EnableCaching | 开启基于注解的缓存 |
keyGenerator | 缓存数据时key生成策略 |
serialize | 缓存数据时value序列化策略 |
@CacheConfig | 统一配置本类的缓存注解的属性 |
安装docker
开机启动docker
检验docker是否安装成功
docker安装redis
docker检测是否安装成功redis
docker启动redis并设置端口映射(-d表示后台运行)
查看redis是否启动成功
在看代码前先看看目录结构吧(在这里使用ssm来整合redis)
数据库表结构
pom.xml文件,这里主要是引入spring-boot-starter-cache依赖
配置文件application.yml,配置redis
启动类加入@EnableCaching注解
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package com.lzh.springbootstudytestcache; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cache.annotation.EnableCaching; @SpringBootApplication @EnableCaching public class SpringBootStudyTestCacheApplication { public static void main(String[] args) { SpringApplication.run(SpringBootStudyTestCacheApplication. class , args); } } |
UserController 类暴露接口
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package com.lzh.springbootstudytestcache.controller; import com.lzh.springbootstudytestcache.model.User; import com.lzh.springbootstudytestcache.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; /** * @author lzh * create 2019-09-24-20:34 */ @RestController public class UserController { @Autowired UserService userService; @GetMapping ( "/user/save" ) public User saveUser( @RequestParam Integer id, @RequestParam String name, @RequestParam Integer age){ User user= userService.save( new User(id,name,age)); return user; } @GetMapping ( "/user/{id}" ) public User getUserById( @PathVariable Integer id){ System.out.println( "id=" +id); User user = userService.findUserById(id); System.out.println( "getUserById - " +user); return user; } @GetMapping ( "/user/update" ) public User updateUser( @RequestParam Integer id, @RequestParam String name, @RequestParam Integer age){ User user= userService.updateUser( new User(id,name,age)); return user; } @GetMapping ( "/user/del/{id}" ) public String deleteUser( @PathVariable Integer id){ System.out.println( "id=" +id); int num = userService.deleteUser(id); if (num > 0 ){ return "删除成功" ; } else { return "删除失败" ; } } } |
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<code class = "hljs" >UserService接口</code> |
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package com.lzh.springbootstudytestcache.service; import com.lzh.springbootstudytestcache.model.User; /** * @author lzh * create 2019-09-24-9:14 */ public interface UserService { User save(User user); User findUserById(Integer id); User updateUser(User user); int deleteUser(Integer id); } |
UserService实现类
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package com.lzh.springbootstudytestcache.service.impl; import com.lzh.springbootstudytestcache.mapper.UserMapper; import com.lzh.springbootstudytestcache.model.User; import com.lzh.springbootstudytestcache.service.UserService; import lombok.extern.log4j.Log4j2; 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.Service; /** * @author lzh * create 2019-09-24-9:14 */ @Service @Log4j2 public class UserServiceImpl implements UserService { @Autowired UserMapper userMapper; @Cacheable (value = "user" ,key = "#user.id" ) @Override public User save(User user) { int saveNum = userMapper.saveUser(user); System.out.println( "saveNum=" +saveNum); return user; } @Cacheable (value = "user" ,key = "#id" ) @Override public User findUserById(Integer id) { log.info( "进入findUserById方法" ); return userMapper.findUserById(id); } @CachePut (value = "user" , key = "#user.id" ) @Override public User updateUser(User user) { int num = userMapper.updateUser(user); System.out.println( "num=" +num); return user; } @CacheEvict (value = "user" ) @Override public int deleteUser(Integer id) { return userMapper.deleteUser(id); } } |
User实体类,加入@Data相当于加入getset方法,@AllArgsConstructor全参构造方法,@ToString重写tostring方法,引入Lombok简化代码
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package com.lzh.springbootstudytestcache.model; import lombok.AllArgsConstructor; import lombok.Data; import lombok.ToString; import java.io.Serializable; /** * @author Levin * @since 2018/5/10 0007 */ @Data @AllArgsConstructor @ToString public class User implements Serializable { private Integer id; private String name; private Integer age; } |
UserMapper持久层,使用mybatis注解@Select、@Update、@Insert、@Delete实现
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package com.lzh.springbootstudytestcache.mapper; import com.lzh.springbootstudytestcache.model.User; import org.apache.ibatis.annotations.*; /** * @author lzh * create 2019-09-24-20:39 */ @Mapper public interface UserMapper { @Select ( "SELECT * FROM User WHERE id = #{id}" ) User findUserById(Integer id); @Update ( "update user set name=#{name},age=#{age} where id=#{id}" ) int updateUser(User user); @Insert ( "insert into user set name=#{name},age=#{age}" ) int saveUser(User user); @Delete ( "DELETE FROM USER WHERE id=#{id}" ) int deleteUser(Integer id); } |
改变默认jdk序列化器
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package com.lzh.springbootstudytestcache.config; import com.fasterxml.jackson.annotation.JsonAutoDetect; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.databind.ObjectMapper; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.serializer.*; /** * @author lzh * create 2019-09-24-22:22 */ import org.springframework.cache.CacheManager; import org.springframework.context.annotation.Primary; import org.springframework.data.redis.cache.RedisCacheConfiguration; import org.springframework.data.redis.cache.RedisCacheManager; import org.springframework.data.redis.cache.RedisCacheWriter; import java.time.Duration; //@Configuration public class MyRedisConfig { //@Bean(name = "redisTemplate") public RedisTemplate<String,Object> redisTemplate(RedisConnectionFactory redisConnectionFactory){ RedisTemplate<String,Object> redisTemplate = new RedisTemplate<>(); redisTemplate.setConnectionFactory(redisConnectionFactory); redisTemplate.setKeySerializer(keySerializer()); redisTemplate.setHashKeySerializer(keySerializer()); redisTemplate.setValueSerializer(valueSerializer()); redisTemplate.setHashValueSerializer(valueSerializer()); return redisTemplate; } //@Primary //@Bean public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory){ //缓存配置对象 RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig(); redisCacheConfiguration = redisCacheConfiguration.entryTtl(Duration.ofMinutes(30L)) //设置缓存的默认超时时间:30分钟 .disableCachingNullValues() //如果是空值,不缓存 .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(keySerializer())) //设置key序列化器 .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer((valueSerializer()))); //设置value序列化器 return RedisCacheManager .builder(RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory)) .cacheDefaults(redisCacheConfiguration).build(); } private RedisSerializer<String> keySerializer() { return new StringRedisSerializer(); } private RedisSerializer<Object> valueSerializer() { return new GenericJackson2JsonRedisSerializer(); } } |
启动srpingboot访问http://localhost:8080/user/1
使用redis可视化工具查看发现多了一个user对象,这就是在执行查询语句的时候保存的缓存
看控制台这里打印出了日志,这是第一次查询,说明执行了sql语句
再次访问http://localhost:8080/user/1,没有执行findUserById方法说明没有执行sql语句,而是直接从redis缓存中读取