提示

使用SpringCache+Redis缓存前，可以先了解一下SpringCache基本概念

快速访问 🚀 SpringCache

使用SpringCache简化缓存功能的实现

- name: 快速访问 🚀 SpringCache 
  desc: 使用SpringCache简化缓存功能的实现
  link: /note/spring-cache/
  bgColor: '#DFEEE7'
  textColor: '#2A3344'

项目集成Redis

由于使用的springboot项目，springCache的依赖已经添加

缓存中使用了redis，需要事先搭建redis

因为缓存是公共使用，所有的service模块都有可能使用缓存，把依赖与部分配置加在service-util模块，其他service模块都可以使用

在 service-util 的pom中添加依赖

<!-- redis -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!-- spring2.X集成redis所需common-pool2-->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
    <version>2.6.0</version>
</dependency>

在 service-util 中添加redis配置bean

创建 com.stt.yygh.common.config.RedisConfig 配置类

• 标记注解 @EnableCaching
  • 开启缓存，并配置Redis缓存管理器
  • 该注解触发后置处理器, 检查每一个Spring bean 的 public 方法是否存在缓存注解。如果找到这样的一个注释, 自动创建一个代理拦截方法调用和处理相应的缓存行为
• 添加 KeyGenerator 类对象，自定义key的生成规则
  • 使用 className+methodName+paramsName
• 配置RedisTemplate
  • 解决存储key value序列化问题
• 配置 CacheManager
  • 配置key value的序列化
  • 配置redis中缓存key的过期时间

package com.stt.yygh.common.config;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.interceptor.KeyGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
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 org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.lang.reflect.Method;
import java.time.Duration;

@Configuration
@EnableCaching
public class RedisConfig {

    // 自定义key规则
    @Bean
    public KeyGenerator keyGenerator() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName());
                sb.append(method.getName());
                for (Object obj : params) {
                    sb.append(obj.toString());
                }
                return sb.toString();
            }
        };
    }

    // 设置RedisTemplate规则
    @Bean
    public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

        //解决查询缓存转换异常的问题
        ObjectMapper om = new ObjectMapper();

        // 指定要序列化的域，field,get和set,以及修饰符范围，ANY是都有包括private和public
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);

        // 指定序列化输入的类型，类必须是非final修饰的，final修饰的类，比如String,Integer等会跑出异常
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);

        //序列号key value
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);

        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer);

        redisTemplate.afterPropertiesSet();
        return redisTemplate;
    }

    // 设置CacheManager缓存规则
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory factory) {
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

        //解决查询缓存转换异常的问题
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);

        // 配置序列化（解决乱码的问题）,过期时间600秒
        RedisCacheConfiguration config = RedisCacheConfiguration
            	.defaultCacheConfig()
                .entryTtl(Duration.ofSeconds(600))
                .serializeKeysWith(RedisSerializationContext
                        .SerializationPair.fromSerializer(redisSerializer))
                .serializeValuesWith(RedisSerializationContext
                        .SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
                .disableCachingNullValues();

        return RedisCacheManager.builder(factory)
                .cacheDefaults(config)
                .build();
    }
}

在 service-cmn 中添加redis配置

在 application.properties中添加如下配置

# redis配置
spring.redis.host=localhost
spring.redis.port=6379
spring.redis.database= 0
spring.redis.timeout=1800000

spring.redis.lettuce.pool.max-active=20
spring.redis.lettuce.pool.max-wait=-1
# 最大阻塞等待时间(负数表示没限制)
spring.redis.lettuce.pool.max-idle=5
spring.redis.lettuce.pool.min-idle=0

在数据字典中使用

使用@Cacheable 和 @CacheEvict 注解

package com.stt.yygh.cmn.service.impl;

import com.alibaba.excel.EasyExcel;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.stt.yygh.cmn.listener.DictListener;
import com.stt.yygh.cmn.mapper.DictMapper;
import com.stt.yygh.cmn.service.DictService;
import com.stt.yygh.model.cmn.Dict;
import com.stt.yygh.model.cmn.DictExcelVo;
import org.springframework.beans.BeanUtils;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

@Service
public class DictServiceImpl extends ServiceImpl<DictMapper, Dict> implements DictService {

    //根据数据id查询子数据列表
    @Cacheable(value = "dict",keyGenerator = "keyGenerator")
    @Override
    public List<Dict> findChildData(Long id) {
      ...
...
    }

    //导入数据字典
    @CacheEvict(value = "dict", allEntries=true)
    @Override
    public void importDictData(MultipartFile file) {
...
    }
}

测试

• 在查询数据字典后，查看redis中是否有缓存

127.0.0.1:6379> keys *
1) "dict::com.stt.yygh.cmn.service.impl.DictServiceImplfindChildData1"
2) "test222"
3) "dict::com.stt.yygh.cmn.service.impl.DictServiceImplfindChildData86"
127.0.0.1:6379> get dict::com.stt.yygh.cmn.service.impl.DictServiceImplfindChildData1
"[\"java.util.ArrayList\",[[\"com.stt.yygh.model.cmn.Dict\",{\"id\":86,\"createTime\":[\"java.util.Date\",\"2019-06-10 02:43:35\"],\"updateTime\":[\"java.util.Date\",1592898228000],\"isDeleted\":0,\"param\":[\"java.util.HashMap\",{}],\"parentId\":1,\"name\":\"\xe7\x9c\x81\",\"value\":\"86\",\"dictCode\":\"Province\",\"hasChildren\":true}],[\"com.stt.yygh.model.cmn.Dict\",{\"id\":100,\"createTime\":[\"java.util.Date\",\"2021-12-04 01:28:58\"],\"updateTime\":[\"java.util.Date\",1638581407000],\"isDeleted\":0,\"param\":[\"java.util.HashMap\",{}],\"parentId\":1,\"name\":\"\xe6\x89\x8b\xe6\x9c\xba\",\"value\":\"100\",\"dictCode\":\"phone\",\"hasChildren\":true}],[\"com.stt.yygh.model.cmn.Dict\",{\"id\":10000,\"createTime\":[\"java.util.Date\",\"2019-06-10 02:43:32\"],\"updateTime\":[\"java.util.Date\",1592191604000],\"isDeleted\":0,\"param\":[\"java.util.HashMap\",{}],\"parentId\":1,\"name\":\"\xe5\x8c\xbb\xe9\x99\xa2\xe7\xad\x89\xe7\xba\xa7\",\"value\":null,\"dictCode\":\"Hostype\",\"hasChildren\":true}],[\"com.stt.yygh.model.cmn.Dict\",{\"id\":20000,\"createTime\":[\"java.util.Date\",\"2019-06-10 02:43:32\"],\"updateTime\":[\"java.util.Date\",1592290377000],\"isDeleted\":0,\"param\":[\"java.util.HashMap\",{}],\"parentId\":1,\"name\":\"\xe8\xaf\x81\xe4\xbb\xb6\xe7\xb1\xbb\xe5\x9e\x8b\",\"value\":\"20000\",\"dictCode\":\"CertificatesType\",\"hasChildren\":true}],[\"com.stt.yygh.model.cmn.Dict\",{\"id\":30000,\"createTime\":[\"java.util.Date\",\"2019-06-10 02:43:32\"],\"updateTime\":[\"java.util.Date\",1591608399000],\"isDeleted\":0,\"param\":[\"java.util.HashMap\",{}],\"parentId\":1,\"name\":\"\xe5\xad\xa6\xe5\x8e\x86\",\"value\":\"30000\",\"dictCode\":\"Education\",\"hasChildren\":true}],[\"com.stt.yygh.model.cmn.Dict\",{\"id\":99100,\"createTime\":[\"java.util.Date\",\"2019-06-11 02:39:11\"],\"updateTime\":[\"java.util.Date\",1591608399000],\"isDeleted\":0,\"param\":[\"java.util.HashMap\",{}],\"parentId\":1,\"name\":\"\xe6\xb0\x91\xe6\x97\x8f\",\"value\":\"99100\",\"dictCode\":\"Nation\",\"hasChildren\":true}]]]"