学了springcloud如何操作数据库进行增删改查，又学了springcloud如何操作reids把数据存储到redis。今天结合数据库操作和reids操作，来看看如何使用SpringCache。SpringCache提供了基于注解的缓存配置方法。它本质上不是一个具体的缓存实现方案（例如EHCache），而是一个对缓存使用的抽象和封装，通过在已有代码中打上几个预定义的注释，就可以实现希望达到的缓存效果。SpringCache支持跟第三方缓存例如EHCache、Redis集成；另外也提供了开箱即用的默认实现，可以直接拿来使用。SpringCache支持使用SpEL（Spring ExpressionLanguage）来定义缓存的key和各种condition，因此具备相当的灵活性，并可以支持非常复杂的语义。
1、新建项目sc-redis-cache，对用的pom.xml文件如下
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>spring-cloud</groupId>
<artifactId>sc-redis-cache</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>sc-redis-cache</name>
<url>http://maven.apache.org</url>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
</parent>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Finchley.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
<groupId>com.zaxxer</groupId>
<artifactId>HikariCP</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.3</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>2、新建springboot启动类RedisCacheApplication.java
package sc.redis.cache;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import
org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
/**
* 更多资源关注公众号： java乐园
*
* @author Administrator
*
*/
@SpringBootApplication
@EnableCaching // 启动缓存
@MapperScan(basePackages="sc.redis.cache.dao")
public class RedisCacheApplication {
public static void main(String[] args) {
SpringApplication.run(RedisCacheApplication.class,args);
}
} 备注：@MapperScan(basePackages="sc.redis.cache.dao")该注解的basePackages一定是DAO所在包最终报名。
如果写成@MapperScan(basePackages="sc.redis.cache")这样在测试中将报错：
3、新建配置文件application.yml
server:
port: 9003
spring:
application:
name: sc-redis-cache
datasource:
driverClassName: com.mysql.jdbc.Driver
url:jdbc:mysql://localhost:3306/sc?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8
username:root
password: root
type: com.zaxxer.hikari.HikariDataSource
hikari:
minimum-idle: 5
maximum-pool-size: 15
auto-commit: true
idle-timeout: 30000
pool-name: DatebookHikariCP
max-lifetime: 1800000
connection-timeout: 30000
connection-test-query: SELECT 1
cache:
type: REDIS
redis:
timeToLive: 200000 #缓存超时时间ms
cache-null-values: false #是否缓存空值
redis:
host: 127.0.0.1
password:
port: 6379
timeout: 10000 # 连接超时时间（毫秒）
database: 0 # Redis默认情况下有16个分片，这里配置具体使用的分片，默认是0
lettuce:
pool:
max-active: 8 # 连接池最大连接数（使用负值表示没有限制）默认 8
max-wait: -1 # 连接池最大阻塞等待时间（使用负值表示没有限制）默认 -1
max-idle: 8 # 连接池中的最大空闲连接默认 8
min-idle:0 # 连接池中的最小空闲连接默认 0
logging:
level:
sc.redis.cache.dao: debug备注：配置文件中有连接数据库的配置信息和连接redis的配置信息，同时配置了打印sql语句的日志级别
4、新建自定义reids序列化方式RedisCacheSerializeConfiguration.java类
package sc.redis.cache.config;
import java.time.Duration;
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.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
@Configuration
publicclass RedisCacheSerializeConfiguration{
///**
// *二选一
// * 设置 redis数据默认过期时间设置@cacheable序列化方式
// *
// * @return
// */
//@Bean
//public RedisCacheConfiguration redisCacheConfiguration() {
// RedisCacheConfigurationconfiguration = RedisCacheConfiguration.defaultCacheConfig();
// configuration =configuration.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(valueSerializer()))
// .entryTtl(Duration.ofDays(30));
//configuration.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(keySerializer()));
// return configuration;
//}
/**
* 二选一
* 设置 redis数据默认过期时间设置@cacheable序列化方式
*
* @param connectionFactory
* @return
*/
@Bean
public RedisCacheManager cacheManager(RedisConnectionFactory connectionFactory) {
RedisCacheConfigurationconfig = RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofDays(30))
.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(keySerializer()))
.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(valueSerializer()))
.disableCachingNullValues();
RedisCacheManager redisCacheManager = RedisCacheManager.builder(connectionFactory).cacheDefaults(config)
.transactionAware().build();
System.out.println("自定义RedisCacheManager加载完成");
returnredisCacheManager;
}
private RedisSerializer<String> keySerializer() {
returnnewStringRedisSerializer();
}
private RedisSerializer<Object> valueSerializer() {
returnnewGenericJackson2JsonRedisSerializer();
}
}5、启动相关类请参照源码，目录结构如下
6、编写单元测试类
package sc.redis.cache;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import sc.redis.cache.model.User;
import sc.redis.cache.service.UserService;
@RunWith(SpringRunner.class)
@SpringBootTest
publicclass TestRedis {
privatestaticfinal Logger logger =LoggerFactory.getLogger(TestRedis.class);
@Autowired
privateUserService userService;
@Test
publicvoid add() {
User u = new User();
u.setId(4L);
u.setUserName("huangjinjin");
u.setPosition("cto");
u.setAge(24);
userService.addUser(u);
}
@Test
publicvoid get() {
User u =userService.getUser(4L);
logger.debug("userName = "+ u.getUserName());
}
}7、进行单元测试
运行add方法添加一条数据到数据库：
日志：
第一次运行get方法：
日志：
使用redis-cli查看redis，数据已经插入缓存
第二次运行get方法：
日志：
发现没有打印任何sql语句，说明数据是从redis获取的，没有去数据库查询数据。
源码：
https://gitee.com/hjj520/spring-cloud-2.x/tree/master/sc-redis-cache本文作者：java乐园
