安装Redis请参考：《CentOS快速安装Redis》
一、springboot集成redis并实现DB与缓存同步
1.添加redis及数据库相关依赖（pom.xml）
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-redis</artifactId> <version>1.4.7.RELEASE</version> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies>
2.添加数据库、mybatis、redis相关配置（application.properties）
#数据库相关配置 spring.datasource.driverClassName=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://192.168.15.129:3306/springboot?useUnicode=true&characterEncoding=utf-8&useSSL=false spring.datasource.username=root spring.datasource.password=123456 #Mybatis相关配置 mybatis.type-aliases-package=com.lianjinsoft.pojo mybatis.config-locations=classpath:mybatis/mybatis-config.xml mybatis.mapper-locations=classpath:mybatis/mapper/*.xml #Redis相关配置 #数据库索引（默认为0） spring.redis.database=0 #服务器地址 spring.redis.host=192.168.15.129 #服务器连接端 spring.redis.port=6379 #服务器连接密码（默认为空） spring.redis.password=123456 #连接池最大连接数（使用负值表示没有限制） spring.redis.pool.max-active=100 #连接池最大阻塞等待时间（使用负值表示没有限制） spring.redis.pool.max-wait=10000 #连接池中的最大空闲连接 spring.redis.pool.max-idle=8 #连接池中的最小空闲连接 spring.redis.pool.min-idle=2 #连接超时时间（毫秒） spring.redis.timeout=5000
3.springboot启动类，增加Mybatis扫描注解
@MapperScan("com.lianjinsoft.mapper")
@SpringBootApplication
public class RedisApplication {
public static void main(String[] args) {
SpringApplication.run(RedisApplication.class, args);
}
}
4.增加pojo数据表映射类
public class Order {
private Integer id;
private String orderNo;
private String orderName;
private BigDecimal amount;
private Date addTime;
//省略get、set
}
5.增加Mapper数据持久层操作方法
public interface OrderMapper {
void addOrder(Order order);
void delOrder(String orderNo);
void updOrder(Order order);
Order queryOrderByNo(String orderNo);
}
6.增加Mybatis主配置文件
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <typeAliases> <typeAlias alias="Integer" type="java.lang.Integer" /> <typeAlias alias="Long" type="java.lang.Long" /> <typeAlias alias="HashMap" type="java.util.HashMap" /> <typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" /> <typeAlias alias="ArrayList" type="java.util.ArrayList" /> <typeAlias alias="LinkedList" type="java.util.LinkedList" /> </typeAliases> </configuration>
7.增加Mapper对应的配置文件及sql
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.lianjinsoft.mapper.OrderMapper" > <resultMap id="BaseResultMap" type="com.lianjinsoft.pojo.Order" > <id column="id" property="id" jdbcType="INTEGER" /> <result column="order_no" property="orderNo" jdbcType="VARCHAR" /> <result column="order_name" property="orderName" jdbcType="VARCHAR" /> <result column="amount" property="amount" jdbcType="DECIMAL"/> <result column="add_time" property="addTime" jdbcType="TIMESTAMP" /> </resultMap> <sql id="Base_Column_List" > id, order_no, order_name, amount, add_time </sql> <select id="queryOrderByNo" parameterType="java.lang.String" resultMap="BaseResultMap" > SELECT <include refid="Base_Column_List" /> FROM orders WHERE order_no = #{orderNo} </select> <insert id="addOrder" parameterType="com.lianjinsoft.pojo.Order" > INSERT INTO orders (order_no,order_name,amount,add_time) VALUES (#{orderNo}, #{orderName}, #{amount}, #{addTime}) </insert> <delete id="delOrder" parameterType="java.lang.String" > DELETE FROM orders WHERE order_no =#{orderNo} </delete> <update id="updOrder" parameterType="com.lianjinsoft.pojo.Order" > UPDATE orders SET order_name=#{orderName} WHERE id=#{id} </update> </mapper>
8.添加缓存配置（启用缓存）
@Configuration
@EnableCaching
public class RedisConfig extends CachingConfigurerSupport {
@Bean
public KeyGenerator keyGenerator() {
return new KeyGenerator() {
@Override
public Object generate(Object target, Method method, Object... params) {
StringBuilder sf = new StringBuilder();
sf.append(target.getClass().getName());
sf.append("_");
sf.append(method.getName());
for (Object obj : params) {
sf.append("_");
sf.append(obj.toString());
}
return sf.toString();
}
};
}
@Bean
public CacheManager cacheManager(RedisTemplate redisTemplate) {
return new RedisCacheManager(redisTemplate);
}
@Bean
public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory factory) {
StringRedisTemplate template = new StringRedisTemplate(factory);
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.setValueSerializer(jackson2JsonRedisSerializer);
template.afterPropertiesSet();
return template;
}
}
9.增加OrderService接口及实现类
public interface OrderService {
void addOrder(Order order);
void delOrder(String orderNo);
void updOrder(Order order);
Order queryOrderByNo(String orderNo);
}
@Service
public class OrderServiceImpl implements OrderService{
private final String prefix = "order:";
@Autowired
private OrderMapper orderMapper;
@Autowired
private RedisTemplate redisTemplate;
@Override
public void addOrder(Order order) {
orderMapper.addOrder(order);
redisTemplate.opsForValue().set(prefix+order.getOrderNo(), order);
LogUtil.info("新增订单，添加缓存："+order);
}
@Override
public void delOrder(String orderNo) {
if(redisTemplate.hasKey(prefix+orderNo)){
redisTemplate.delete(prefix+orderNo);
LogUtil.info("删除缓存数据："+orderNo);
}
orderMapper.delOrder(orderNo);
}
@Override
public void updOrder(Order order) {
orderMapper.updOrder(order);
if(redisTemplate.hasKey(prefix+order.getOrderNo())){
redisTemplate.opsForValue().set(prefix+order.getOrderNo(), order);
LogUtil.info("更新缓存订单信息："+order);
}
}
@Override
public Order queryOrderByNo(String orderNo) {
Order order = (Order)redisTemplate.opsForValue().get(prefix+orderNo);
if(order != null){
LogUtil.info("从缓存获取到数据："+order);
return order;
}
order = orderMapper.queryOrderByNo(orderNo);
if(order != null){
redisTemplate.opsForValue().set(prefix+orderNo, order);
}
return order;
}
}
10.增加OrderServiceTests测试类（Junit）
@RunWith(SpringRunner.class)
@SpringBootTest
public class OrderServiceTests {
@Autowired
private OrderService orderService;
@Test
public void test1_add() {
//添加订单
orderService.addOrder(new Order("100001", "XX手机", new BigDecimal("4999")));
}
@Test
public void test2_query() {
//查询订单
orderService.queryOrderByNo("100001");
}
@Test
public void test3_update() {
//先查询订单信息
Order order = orderService.queryOrderByNo("100001");
order.setOrderName("国民手机");
//更新DB及缓存
orderService.updOrder(order);
//再次查询
orderService.queryOrderByNo("100001");
}
@Test
public void test4_del() {
//删除DB及缓存
orderService.delOrder("100001");
//再次查询
orderService.queryOrderByNo("100001");
}
}
10.1）执行test1_add()方法
10:57:45.873 [main] INFO c.l.service.OrderServiceTests - Starting OrderServiceTests on LAPTOP-1DF7S904 with PID 8316 (started by lianjinsoft in E:workspacespringbootspring-boot-redis) 10:57:45.875 [main] INFO c.l.service.OrderServiceTests - No active profile set, falling back to default profiles: default 10:57:45.908 [main] INFO o.s.c.a.AnnotationConfigApplicationContext - Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:57:45 CST 2018]; root of context hierarchy 10:57:46.233 [main] INFO o.s.d.r.c.RepositoryConfigurationDelegate - Multiple Spring Data modules found, entering strict repository configuration mode! 10:57:47.370 [main] WARN o.s.b.s.r.RedisStarterDeprecationWarningAutoConfiguration - spring-boot-starter-redis is deprecated as of Spring Boot 1.4, please migrate to spring-boot-starter-data-redis 10:57:47.399 [main] INFO c.l.service.OrderServiceTests - Started OrderServiceTests in 1.752 seconds (JVM running for 2.512) 10:57:47.931 [main] INFO com.lianjinsoft.util.LogUtil - 新增订单，添加缓存：Order [id=null, orderNo=100001, orderName=XX手机, amount=4999, addTime=Mon Apr 23 10:57:47 CST 2018] 10:57:47.939 [Thread-2] INFO o.s.c.a.AnnotationConfigApplicationContext - Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:57:45 CST 2018]; root of context hierarchy
从日志的第7行可以看出，订单信息已经添加成功。并添加到缓存中。
10.2）执行test2_query()方法
10:58:04.273 [main] INFO c.l.service.OrderServiceTests - Starting OrderServiceTests on LAPTOP-1DF7S904 with PID 20492 (started by lianjinsoft in E:workspacespringbootspring-boot-redis) 10:58:04.277 [main] INFO c.l.service.OrderServiceTests - No active profile set, falling back to default profiles: default 10:58:04.301 [main] INFO o.s.c.a.AnnotationConfigApplicationContext - Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:58:04 CST 2018]; root of context hierarchy 10:58:04.618 [main] INFO o.s.d.r.c.RepositoryConfigurationDelegate - Multiple Spring Data modules found, entering strict repository configuration mode! 10:58:05.920 [main] WARN o.s.b.s.r.RedisStarterDeprecationWarningAutoConfiguration - spring-boot-starter-redis is deprecated as of Spring Boot 1.4, please migrate to spring-boot-starter-data-redis 10:58:05.953 [main] INFO c.l.service.OrderServiceTests - Started OrderServiceTests in 1.903 seconds (JVM running for 2.659) 10:58:06.101 [main] INFO com.lianjinsoft.util.LogUtil - 从缓存获取数据：Order [id=null, orderNo=100001, orderName=XX手机, amount=4999, addTime=Mon Apr 23 10:57:47 CST 2018] 10:58:06.109 [Thread-2] INFO o.s.c.a.AnnotationConfigApplicationContext - Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:58:04 CST 2018]; root of context hierarchy
从日志的第7行可以看出，查询信息从缓存中获取（没有查询数据库）。
10.3）执行test3_update()方法
10:58:17.172 [main] INFO c.l.service.OrderServiceTests - Starting OrderServiceTests on LAPTOP-1DF7S904 with PID 12316 (started by lianjinsoft in E:workspacespringbootspring-boot-redis) 10:58:17.172 [main] INFO c.l.service.OrderServiceTests - No active profile set, falling back to default profiles: default 10:58:17.207 [main] INFO o.s.c.a.AnnotationConfigApplicationContext - Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:58:17 CST 2018]; root of context hierarchy 10:58:17.530 [main] INFO o.s.d.r.c.RepositoryConfigurationDelegate - Multiple Spring Data modules found, entering strict repository configuration mode! 10:58:18.679 [main] WARN o.s.b.s.r.RedisStarterDeprecationWarningAutoConfiguration - spring-boot-starter-redis is deprecated as of Spring Boot 1.4, please migrate to spring-boot-starter-data-redis 10:58:18.750 [main] INFO c.l.service.OrderServiceTests - Started OrderServiceTests in 1.809 seconds (JVM running for 2.553) 10:58:19.032 [main] INFO com.lianjinsoft.util.LogUtil - 从缓存获取数据：Order [id=null, orderNo=100001, orderName=XX手机, amount=4999, addTime=Mon Apr 23 10:57:47 CST 2018] 10:58:19.450 [main] INFO com.lianjinsoft.util.LogUtil - 更新缓存订单信息：Order [id=null, orderNo=100001, orderName=国民手机, amount=4999, addTime=Mon Apr 23 10:57:47 CST 2018] 10:58:19.454 [main] INFO com.lianjinsoft.util.LogUtil - 从缓存获取数据：Order [id=null, orderNo=100001, orderName=国民手机, amount=4999, addTime=Mon Apr 23 10:57:47 CST 2018] 10:58:19.458 [Thread-2] INFO o.s.c.a.AnnotationConfigApplicationContext - Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:58:17 CST 2018]; root of context hierarchy
从日志的第7~9行可以看出，订单先从缓存中获取，然后执行了更新DB、更新缓存，最后再从缓存中获取到了订单信息。
10.4）执行test4_del()方法
10:58:34.652 [main] INFO c.l.service.OrderServiceTests - Starting OrderServiceTests on LAPTOP-1DF7S904 with PID 7428 (started by lianjinsoft in E:workspacespringbootspring-boot-redis) 10:58:34.652 [main] INFO c.l.service.OrderServiceTests - No active profile set, falling back to default profiles: default 10:58:34.676 [main] INFO o.s.c.a.AnnotationConfigApplicationContext - Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:58:34 CST 2018]; root of context hierarchy 10:58:34.997 [main] INFO o.s.d.r.c.RepositoryConfigurationDelegate - Multiple Spring Data modules found, entering strict repository configuration mode! 10:58:36.107 [main] WARN o.s.b.s.r.RedisStarterDeprecationWarningAutoConfiguration - spring-boot-starter-redis is deprecated as of Spring Boot 1.4, please migrate to spring-boot-starter-data-redis 10:58:36.140 [main] INFO c.l.service.OrderServiceTests - Started OrderServiceTests in 1.856 seconds (JVM running for 2.61) 10:58:36.281 [main] INFO com.lianjinsoft.util.LogUtil - 删除缓存数据：100001 10:58:36.689 [main] INFO com.lianjinsoft.util.LogUtil - 从数据库获取数据：null 10:58:36.693 [Thread-2] INFO o.s.c.a.AnnotationConfigApplicationContext - Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@306cf3ea: startup date [Mon Apr 23 10:58:34 CST 2018]; root of context hierarchy
从日志的第7、8行可以看出，订单信息已经从DB、缓存中删除了。
注意：
本案例只是简单的介绍如何将DB与缓存数据同步操作，并不一定适合您当前的业务需求。并且以上操作不能保证缓存与DB数据完全一致。
二、springboot集成redis并实现分布式session缓存
分布式session共享有很多方案，其中缓存托管就是主流一种实现。
1.添加session缓存相关依赖（pom.xml）
<dependency> <groupId>org.springframework.session</groupId> <artifactId>spring-session-data-redis</artifactId> </dependency>
2.添加session配置（启用session缓存）
maxInactiveIntervalInSeconds: 设置session失效时间。
@Configuration
@EnableRedisHttpSession(maxInactiveIntervalInSeconds = 60*30)
public class SessionConfig {
}
3.测试
3.1）修改本地服务端口并启动，模拟分布式应用部署（application.properties）
#服务端口（8001、8002、8003）
server.port=8001
3.2）分别调用各应用接口，查看sessionId
3.3）查看redis缓存信息
如图：缓存中的sessionId与接口返回信息一致。
源代码：https://gitee.com/skychenjiajun/spring-boot