虚拟机linux+centos7+docker+springboot+Redis的使用 Redis 一、Redis介绍 二、项目集成Redis(前提是在虚拟机已经配置好了redis服务,本文是基于虚拟机linux+centos7+docker+redis的案例)

虚拟机linux+centos7+docker+springboot+Redis的使用
Redis
一、Redis介绍
二、项目集成Redis(前提是在虚拟机已经配置好了redis服务,本文是基于虚拟机linux+centos7+docker+redis的案例)

虚拟机linux+centos7+docker+redis的安装和配置参照:https://www.cnblogs.com/konglxblog/p/14968147.html

一、Redis介绍

  Redis是当前比较热门的NOSQL系统之一,它是一个开源的使用ANSI c语言编写的key-value存储系统(区别于MySQL的二维表格的形式存储。)。和Memcache类似,但很大程度补偿了Memcache的不足。和Memcache一样,Redis数据都是缓存在计算机内存中,不同的是,Memcache只能将数据缓存到内存中,无法自动定期写入硬盘,这就表示,一断电或重启,内存清空,数据丢失。所以Memcache的应用场景适用于缓存无需持久化的数据。而Redis不同的是它会周期性的把更新的数据写入磁盘或者把修改操作写入追加的记录文件,实现数据的持久化。

Redis的特点:

1,Redis读取的速度是110000次/s,写的速度是81000次/s;

2,原子 。Redis的所有操作都是原子性的,同时Redis还支持对几个操作全并后的原子性执行。

3,支持多种数据结构:string(字符串);list(列表);hash(哈希),set(集合);zset(有序集合)

4,持久化,集群部署

5,支持过期时间,支持事务,消息订阅

二、项目集成Redis(前提是在虚拟机已经配置好了redis服务,本文是基于虚拟机linux+centos7+docker+redis的案例)

1.pom.xml文件配置

<!-- 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>

2.属性文件配置

# 服务端口
server.port=8004
# 服务名
spring.application.name=service-cms

# mysql数据库连接
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/zxjy?serverTimezone=GMT%2B8&useSSL=false
spring.datasource.username=root
spring.datasource.password=123

#返回json的全局时间格式
spring.jackson.date-format=yyyy-MM-dd HH:mm:ss
spring.jackson.time-zone=GMT+8

#配置mapper xml文件的路径
mybatis-plus.mapper-locations=classpath:com/stu/cmsservice/mapper/xml/*.xml

#mybatis日志
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl

#redis配置,其中host是安装redis的虚拟机的ip,6379是redis的端口号 spring.redis.host=192.168.58.128 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

3.redis配置类

package com.stu.servicebase;

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.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
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.time.Duration;

@EnableCaching
@Configuration
public class RedisConfig extends CachingConfigurerSupport {

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        template.setConnectionFactory(factory);
        //key序列化方式
        template.setKeySerializer(redisSerializer);
        //value序列化
        template.setValueSerializer(jackson2JsonRedisSerializer);
        //value hashmap序列化
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        return template;
    }

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

4.业务层添加redis缓存注解

package com.stu.educms.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.stu.educms.entity.CrmBanner;
import com.stu.educms.mapper.CrmBannerMapper;
import com.stu.educms.service.ICrmBannerService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

import java.sql.Wrapper;
import java.util.List;

/**
 * <p>
 * 首页banner表 服务实现类
 * </p>
 *
 * @author stu
 * @since 2021-06-27
 */
@Service
public class CrmBannerServiceImpl extends ServiceImpl<CrmBannerMapper, CrmBanner> implements ICrmBannerService {

    @Cacheable(value = "banner", key = "'selectBannerList'")
    @Override
    public List<CrmBanner> getAllBanner() {
        QueryWrapper wrapper = new QueryWrapper();
        wrapper.orderByDesc("id");
        wrapper.last("limit 2");
        List<CrmBanner> list = baseMapper.selectList(wrapper);
        return list;
    }
}

5.虚拟机查看redis缓存

虚拟机linux+centos7+docker+springboot+Redis的使用
Redis
一、Redis介绍
二、项目集成Redis(前提是在虚拟机已经配置好了redis服务,本文是基于虚拟机linux+centos7+docker+redis的案例)

6.虚拟机的ip,用命令ifconfig查看linux虚拟机的ip,用于属性文件里redis的host的值

[root@localhost ~]# ifconfig
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255
        inet6 fe80::42:a9ff:fe01:7c3  prefixlen 64  scopeid 0x20<link>
        ether 02:42:a9:01:07:c3  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 23  bytes 2820 (2.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.58.128  netmask 255.255.255.0  broadcast 192.168.58.255
        inet6 fe80::f635:8bb8:ac54:e24d  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:4f:e1:be  txqueuelen 1000  (Ethernet)
        RX packets 1193  bytes 857370 (837.2 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 324  bytes 27776 (27.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 64  bytes 5568 (5.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 64  bytes 5568 (5.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

veth5f1ecb6: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::3809:acff:fe81:47ef  prefixlen 64  scopeid 0x20<link>
        ether 3a:09:ac:81:47:ef  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 31  bytes 3476 (3.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

virbr0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        inet 192.168.122.1  netmask 255.255.255.0  broadcast 192.168.122.255
        ether 52:54:00:67:e1:3b  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

7.springboot缓存注解

(1)缓存@Cacheable

  根据方法对其返回结果进行缓存,下次请求时,如果缓存存在,则直接读取缓存数据返回;如果缓存不存在,则执行方法,并把返回的结果存入缓存中。一般用在查询方法上。

查看源码,属性值如下:

属性/方法名

解释

value

缓存名,必填,它指定了你的缓存存放在哪块命名空间

cacheNames

与 value 差不多,二选一即可

key

可选属性,可以使用 SpEL 标签自定义缓存的key

(2)缓存@CachePut

  使用该注解标志的方法,每次都会执行,并将结果存入指定的缓存中。其他方法可以直接从响应的缓存中读取缓存数据,而不需要再去查询数据库。一般用在新增方法上。

查看源码,属性值如下:

属性/方法名

解释

value

缓存名,必填,它指定了你的缓存存放在哪块命名空间

cacheNames

与 value 差不多,二选一即可

key

可选属性,可以使用 SpEL 标签自定义缓存的key

(3)缓存@CacheEvict

  使用该注解标志的方法,会清空指定的缓存。一般用在更新或者删除方法上

查看源码,属性值如下:

属性/方法名

解释

value

缓存名,必填,它指定了你的缓存存放在哪块命名空间

cacheNames

与 value 差不多,二选一即可

key

可选属性,可以使用 SpEL 标签自定义缓存的key

allEntries

是否清空所有缓存,默认为 false。如果指定为 true,则方法调用后将立即清空所有的缓存

beforeInvocation

是否在方法执行前就清空,默认为 false。如果指定为 true,则在方法执行前就会清空缓存