Spring Boot - 使用 redis 缓存数据

实体类

package com.lfsun.springbootcacheredis.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

/**
 * <p>
 * 用户实体
 * </p>
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User implements Serializable {
    private static final long serialVersionUID = 2892248514883451461L;
    /**
     * 主键id
     */
    private Long id;
    /**
     * 姓名
     */
    private String name;
}

redis配置

spring:
  redis:
    # 连接超时时间（记得添加单位，Duration）
    # Redis默认情况下有16个分片，这里配置具体使用的分片
    # database: 0
    lettuce:
      pool:
        # 连接池最大连接数（使用负值表示没有限制） 默认 8
        max-active: 8
        # 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-wait: -1ms
        # 连接池中的最大空闲连接 默认 8
        max-idle: 8
        # 连接池中的最小空闲连接 默认 0
        min-idle: 0
  cache:
    # 一般来说是不用配置的，Spring Cache 会根据依赖的包自行装配
    type: redis
  data:
    redis:
      host: localhost
      timeout: 10000ms
logging:
  level:
    com.lfsun: debug

package com.lfsun.springbootcacheredis.config;

import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
import org.springframework.cache.CacheManager;
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.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.io.Serializable;

/**
 * <p>
 * redis配置
 * </p>
 */
@Configuration
@AutoConfigureAfter(RedisAutoConfiguration.class)
@EnableCaching
public class RedisConfig {

    /**
     * 默认情况下的模板只能支持RedisTemplate<String, String>，也就是只能存入字符串，因此支持序列化
     */
    @Bean
    public RedisTemplate<String, Serializable> redisCacheTemplate(LettuceConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, Serializable> template = new RedisTemplate<>();
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }

    /**
     * 配置使用注解的时候缓存配置，默认是序列化反序列化的形式，加上此配置则为 json 形式
     */
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory factory) {
        // 配置序列化
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig();
        RedisCacheConfiguration redisCacheConfiguration = config.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer())).serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer()));

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

接口与实现类

package com.lfsun.springbootcacheredis.service;


import com.lfsun.springbootcacheredis.entity.User;

/**
 * <p>
 * UserService
 * </p>
 */
public interface UserService {
    /**
     * 保存或修改用户
     *
     * @param user 用户对象
     * @return 操作结果
     */
    User saveOrUpdate(User user);

    /**
     * 获取用户
     *
     * @param id key值
     * @return 返回结果
     */
    User get(Long id);

    /**
     * 删除
     *
     * @param id key值
     */
    void delete(Long id);
}

package com.lfsun.springbootcacheredis.service.impl;

import com.google.common.collect.Maps;
import com.lfsun.springbootcacheredis.entity.User;
import com.lfsun.springbootcacheredis.service.UserService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

import java.util.Map;

/**
 * <p>
 * UserService
 * </p>
 */
@Service
@Slf4j
public class UserServiceImpl implements UserService {
    /**
     * 模拟数据库
     */
    private static final Map<Long, User> DATABASES = Maps.newConcurrentMap();

    /**
     * 初始化数据
     */
    static {
        DATABASES.put(1L, new User(1L, "user1"));
        DATABASES.put(2L, new User(2L, "user2"));
        DATABASES.put(3L, new User(3L, "user3"));
    }

    /**
     * 保存或修改用户
     *
     * @param user 用户对象
     * @return 操作结果
     */
    @CachePut(value = "user", key = "#user.id")
    @Override
    public User saveOrUpdate(User user) {
        DATABASES.put(user.getId(), user);
        log.info("保存用户【user】= {}", user);
        return user;
    }

    /**
     * 获取用户
     *
     * @param id key值
     * @return 返回结果
     */
    @Cacheable(value = "user", key = "#id")
    @Override
    public User get(Long id) {
        // 我们假设从数据库读取
        log.info("查询用户【id】= {}", id);
        return DATABASES.get(id);
    }

    /**
     * 删除
     *
     * @param id key值
     */
    @CacheEvict(value = "user", key = "#id")
    @Override
    public void delete(Long id) {
        DATABASES.remove(id);
        log.info("删除用户【id】= {}", id);
    }
}

测试

package com.lfsun.springbootcacheredis;

import com.lfsun.springbootcacheredis.entity.User;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;

import java.io.Serializable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.IntStream;

/**
 * <p>
 * Redis测试
 * </p>
 */
@Slf4j
public class RedisTest extends SpringBootCacheRedisApplicationTests {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private RedisTemplate<String, Serializable> redisCacheTemplate;

    /**
     * 测试 Redis 操作
     */
    @Test
    public void get() {
        // 测试线程安全，程序结束查看redis中count的值是否为1000
        ExecutorService executorService = Executors.newFixedThreadPool(1000);
        IntStream.range(0, 1000).forEach(i -> executorService.execute(() -> stringRedisTemplate.opsForValue().increment("count", 1)));

        stringRedisTemplate.opsForValue().set("k1", "v1");
        String k1 = stringRedisTemplate.opsForValue().get("k1");
        log.debug("【k1】= {}", k1);

        // 以下演示整合，具体Redis命令可以参考官方文档
        String key = "lfsun:user:1";
        redisCacheTemplate.opsForValue().set(key, new User(1L, "user1"));
        // 对应 String（字符串）
        User user = (User) redisCacheTemplate.opsForValue().get(key);
        log.debug("【user】= {}", user);
    }
}

package com.lfsun.springbootcacheredis.service;


import com.lfsun.springbootcacheredis.SpringBootCacheRedisApplicationTests;
import com.lfsun.springbootcacheredis.entity.User;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * <p>
 * Redis - 缓存测试
 * </p>
 */
@Slf4j
public class UserServiceTest extends SpringBootCacheRedisApplicationTests {
    @Autowired
    private UserService userService;

    /**
     * 获取两次，查看日志验证缓存
     */
    @Test
    public void getTwice() {
        // 模拟查询id为1的用户
        User user1 = userService.get(1L);
        log.debug("【user1】= {}", user1);

        // 再次查询
        User user2 = userService.get(1L);
        log.debug("【user2】= {}", user2);
        // 查看日志，只打印一次日志，证明缓存生效
    }

    /**
     * 先存，再查询，查看日志验证缓存
     */
    @Test
    public void getAfterSave() {
        userService.saveOrUpdate(new User(4L, "测试中文"));

        User user = userService.get(4L);
        log.debug("【user】= {}", user);
        // 查看日志，只打印保存用户的日志，查询是未触发查询日志，因此缓存生效
    }

    /**
     * 测试删除，查看redis是否存在缓存数据
     */
    @Test
    public void deleteUser() {
        // 查询一次，使redis中存在缓存数据
        userService.get(1L);
        // 删除，查看redis是否存在缓存数据
        userService.delete(1L);
    }

}

完整代码案例地址

Spring Boot 集成 redis