Springboot|Springboot 利用redis 作二级缓存
一、导入redis jar包
org.springframework.boot
spring-boot-starter-data-redis
redis.clients
jedis
2.9.0
启动类加上 @EnableCaching注解表示开启缓存功能
@SpringBootApplication
//开启缓存功能
@EnableCaching
public class ShiroApplication {public static void main(String[] args) {
SpringApplication.run(ShiroApplication.class, args);
}}
二、redis配置
#redis配置# Redis数据库索引（默认为0）
spring.redis.database=0
# Redis服务器地址
spring.redis.host=localhost
# Redis服务器连接端口
spring.redis.port=6379
# Redis服务器连接密码（默认为空）
spring.redis.password=
# 连接池最大连接数（使用负值表示没有限制）
spring.redis.jedis.pool.max-idle=8
# 连接池最大阻塞等待时间（使用负值表示没有限制）
spring.redis.jedis.pool.max-wait=-1
# 连接池中的最小空闲连接
spring.redis.jedis.pool.min-idle=0
# 连接超时时间（毫秒）
spring.redis.timeout=10000三、Redis缓存配置类
package com.example.springboot.shiro.core.shiro;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
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.cache.RedisCacheWriter;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import java.lang.reflect.Method;
import java.time.Duration;
/**
* Redis缓存配置类
*
* @author szekinwin
*/
@Configuration
@EnableCaching
public class RedisCacheConfig extends CachingConfigurerSupport {@Value("${spring.redis.host}")
private String host;
@Value("${spring.redis.port}")
private int port;
@Value("${spring.redis.timeout}")
private int timeout;
//缓存管理器
@Bean
public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
.entryTtl(Duration.ofHours(1));
// 设置缓存有效期一小时
return RedisCacheManager
.builder(RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory))
.cacheDefaults(redisCacheConfiguration).build();
}@Beanpublic RedisTemplate redisTemplate(RedisConnectionFactory factory) {RedisTemplate redisTemplate = new RedisTemplate();
redisTemplate.setConnectionFactory(factory);
//key序列化方式;
（不然会出现乱码;
）,但是如果方法上有Long等非String类型的话，会报类型转换错误；//所以在没有自己定义key生成策略的时候，以下这个代码建议不要这么写，可以不配置或者自己实现ObjectRedisSerializer//或者JdkSerializationRedisSerializer序列化方式;
RedisSerializer redisSerializer = new StringRedisSerializer();
//Long类型不可以会出现异常信息;
redisTemplate.setKeySerializer(redisSerializer);
redisTemplate.setHashKeySerializer(redisSerializer);
//设置序列化Value的实例化对象
redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
return redisTemplate;
}
/*** 自定义key.* 此方法将会根据类名+方法名+所有参数的值生成唯一的一个key,即使@Cacheable中的value属性一样，key也会不一样。*/public KeyGenerator keyGenerator() {System.out.println("RedisCacheConfig.keyGenerator()");
return new KeyGenerator(){@Overridepublic Object generate(Object o, Method method, Object... objects) {// This willgenerate a unique key of the class name, the method name//and allmethod parameters appended.StringBuilder sb = new StringBuilder();
sb.append(o.getClass().getName());
sb.append(method.getName());
for (Object obj : objects) {sb.append(obj.toString());
}System.err.print("keyGenerator======>>>>>>" + sb.toString());
return sb.toString();
}};
}
}
注: 如果报类型转换异常,请把热部署or 热加载关闭
四、redisMapper
package com.example.springboot.shiro.user.mapper;
import com.example.springboot.shiro.user.entity.Uuser;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.springframework.cache.annotation.CacheConfig;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
/*
* @Cacheable将查询结果缓存到redis中，（key="#p0"）指定传入的第一个参数作为redis的key。 * @CachePut，指定key，将更新的结果同步到redis中 * @CacheEvict，指定key，删除缓存数据，allEntries=true,方法调用后将立即清除缓存
*/@Mapper
@CacheConfig(cacheNames = "Uuser")
public interface RedisMapper {
@CachePut(value = "https://www.it610.com/article/usercache", key = "#p0")
@Insert("insert into u_user(email,pswd) values(#{email},#{pswd})")
int addUser(@Param("email")String email,@Param("pswd")String pswd);
@Select("select * from u_user where email=#{email}")Uuser findById(@Param("email") String email);
@CachePut(key = "#p0")
@Update("update u_user set email=#{email} where id=#{id}")
void updataById(@Param("id")String id,@Param("email")String email);
//如果指定为 true，则方法调用后将立即清空所有缓存
@CacheEvict(key ="#p0",allEntries=true)
@Delete("delete from u_user where id=#{id}")
int deleteById(@Param("id")int id);
}
注：关于缓存注解也可以标注在Service 类上，两者取其一
@Cacheable将查询结果缓存到redis中，（key="#p0"）指定传入的第一个参数作为redis的key
@CachePut，指定key，将更新的结果同步到redis中
@CacheEvict，指定key，删除缓存数据，allEntries=true(方法调用后将立即清除所有缓存),
@CacheConfig(cacheNames = "Uuser")表示缓存信息放在Uuser里面【Springboot|Springboot 利用redis 作二级缓存】五、Service
@Cacheable(value = "https://www.it610.com/article/demoInfo") //缓存,这里没有指定key.
public Uuser findById(String email) {
System.err.println("LoginService.findById()=========从数据库中进行获取的....email=" + email);
return redisMapper.findById(email);
}@CacheEvict(value = "https://www.it610.com/article/demoInfo")
public void deleteFromCache(String email) {System.err.println("LoginService.delete().从缓存中删除.");
}注：@Cacheable(value ="https://www.it610.com/article/demoInfo") 表示 缓存信息放在demoInfo里面
@CacheEvict(value="https://www.it610.com/article/demoInfo") 表示清除demoInfo里面的缓存里面的信息
六、Controller
@RequestMapping(value = "https://www.it610.com/article/redis",method = RequestMethod.POST)
@ResponseBody
public Uuser findById(String email) {return loginService.findById(email);
}
@RequestMapping(value = "https://www.it610.com/article/delete",method = RequestMethod.POST)
@ResponseBody
public String delete(String email){
loginService.deleteFromCache(email);
return "ok";
}七、测试
第一次：执行findById()方法
keyGenerator======>>>>>>com.example.springboot.shiro.user.service.LoginServicefindByIdadmin2018-07-29 15:31:19.165INFO 10404 --- [nio-8080-exec-1] io.lettuce.core.EpollProvider: Starting without optional epoll library
2018-07-29 15:31:19.165INFO 10404 --- [nio-8080-exec-1] io.lettuce.core.KqueueProvider: Starting without optional kqueue library
keyGenerator======>>>>>>com.example.springboot.shiro.user.service.LoginServicefindByIdadminLoginService.findById()=========从数据库中进行获取的....email=admin
2018-07-29 15:31:20,257 DEBUG DataSourceUtils:114 - Fetching JDBC Connection from DataSource从上图可以看出，数据第一次是从数据库拿出，此时redis 缓存已生成，自定义key已生成
再次执行：执行findById()方法
keyGenerator======>>>>>>com.example.springboot.shiro.user.service.LoginServicefindByIdadmin2018-07-29 15:40:47,598 DEBUG RequestResponseBodyMethodProcessor:278 - Written [{"create_time":{"date":16,"day":4,"hours":11,"minutes":15,"month":5,"seconds":33,"time":1466046933000,"timezoneOffset":-480,"year":116},"email":"admin","id":1,"last_login_time":{"date":29,"day":0,"hours":12,"minutes":55,"month":6,"seconds":4,"time":1532840104000,"timezoneOffset":-480,"year":118},"nickname":"???","pswd":"","salt":"","status":1,"verificationCode":""}] as "application/json" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@987455b]
2018-07-29 15:40:47,599 DEBUG DispatcherServlet:1076 - Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
2018-07-29 15:40:47,599 DEBUG DispatcherServlet:1000 - Successfully completed request从日志中不难看出，第二次查询并没有到数据库中去查询，而是去缓存中调用。
转载于:https://www.cnblogs.com/wang-qiang/p/9432275.html
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