【前言】针对系统中的查询比较频繁的热点数据做缓存，注意不是类似数据库的二级缓存哦，spring的Cacheable这个注解可以对方法级别的返回值直接缓存，还可以在类上打该注解

springboot 版本 2.1.5.RELEASE

1.引入redis

                
     
      org.springframework.boot
                 
     
      spring-boot-starter-data-redis
             
    

2.application.yml

spring:  redis:    host: 127.0.0.1    database: 1    port: 6379    password:    timeout: 5000    jedis:      pool:        max-active: 20        max-idle: 20        min-idle: 10        max-wait: -1ms

3.配置Redisconfig

package com.lkx.springbootfull.redis;import com.fasterxml.jackson.annotation.JsonAutoDetect;import com.fasterxml.jackson.annotation.PropertyAccessor;import com.fasterxml.jackson.databind.ObjectMapper;import org.springframework.boot.context.properties.ConfigurationProperties;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.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;/** * ClassName: RedisConfig * Function:  TODO * Date:      2019-06-07 15:13 * author     likaixuan * version    V1.0 */@Configurationpublic class RedisConfig {    private Duration timeToLive = Duration.ofHours(1);    @Bean    public RedisTemplate
    
      redisTemplate(RedisConnectionFactory redisConnectionFactory) {        RedisTemplate
     
       redisTemplate = new RedisTemplate<>();        redisTemplate.setConnectionFactory(redisConnectionFactory);        // 使用Jackson2JsonRedisSerialize 替换默认序列化        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);        ObjectMapper objectMapper = new ObjectMapper();        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);        // 设置value的序列化规则和 key的序列化规则        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);        redisTemplate.setKeySerializer(new StringRedisSerializer());        redisTemplate.afterPropertiesSet();        return redisTemplate;    }    @Bean    public CacheManager cacheManager(RedisConnectionFactory factory) {        RedisSerializer
      
        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）        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()                .entryTtl(timeToLive)                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))                .disableCachingNullValues();        RedisCacheManager cacheManager = RedisCacheManager.builder(factory)                .cacheDefaults(config)                .build();        return cacheManager;    }}
      
     
    

4.RedisUtils 这个如果是缓存的话可有可无，系统中redis get set操作的公共类

package com.lkx.springbootfull.redis;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.data.redis.core.*;import org.springframework.stereotype.Component;import java.io.Serializable;import java.util.List;import java.util.Set;import java.util.concurrent.TimeUnit;/** * ClassName: RedisUtils * Function:  TODO * Date:      2019-06-07 16:49 * author     likaixuan * version    V1.0 */@Componentpublic class RedisUtils {    @Autowired    private RedisTemplate redisTemplate;//不带事务    /**     * 写入缓存     *     * @param key     * @param value     * @return     */    public boolean set(final String key, Object value) {        boolean result = false;        try {            ValueOperations
    
      operations = redisTemplate.opsForValue();            operations.set(key, value);            result = true;        } catch (Exception e) {            e.printStackTrace();        }        return result;    }    /**     * 写入缓存设置时效时间     *     * @param key     * @param value     * @return     */    public boolean set(final String key, Object value, Long expireTime) {        boolean result = false;        try {            ValueOperations
     
       operations = redisTemplate.opsForValue();            operations.set(key, value);            redisTemplate.expire(key, expireTime, TimeUnit.SECONDS);            result = true;        } catch (Exception e) {            e.printStackTrace();        }        return result;    }    /**     * 批量删除对应的value     *     * @param keys     */    public void remove(final String... keys) {        for (String key : keys) {            remove(key);        }    }    /**     * 批量删除对应的value (带事务,业务代码中用到事务，则需用此方法)     *     * @param keys     */    public void removeTransactional(final String... keys) {        for (String key : keys) {            removeTransactional(key);        }    }    /**     * 批量删除key     *     * @param pattern     */    public void removePattern(final String pattern) {        Set
      
        keys = redisTemplate.keys(pattern);        if (keys.size() > 0)            redisTemplate.delete(keys);    }    /**     * 删除对应的value     *     * @param key     */    public void remove(final String key) {        if (exists(key)) {            redisTemplate.delete(key);        }    }    /**     * 判断缓存中是否有对应的value     *     * @param key     * @return     */    public boolean exists(final String key) {        return redisTemplate.hasKey(key);    }    /**     * 读取缓存     *     * @param key     * @return     */    public Object get(final String key) {        ValueOperations
       
         operations = redisTemplate.opsForValue();        return operations.get(key);    }    /**     * 哈希 添加     *     * @param key     * @param hashKey     * @param value     */    public void hmSet(String key, Object hashKey, Object value) {        HashOperations
        
          hash = redisTemplate.opsForHash();        hash.put(key, hashKey, value);    }    /**     * 哈希获取数据     *     * @param key     * @param hashKey     * @return     */    public Object hmGet(String key, Object hashKey) {        HashOperations
         
           hash = redisTemplate.opsForHash(); return hash.get(key, hashKey); } /** * 列表添加 * * @param k * @param v */ public void lPush(String k, Object v) { ListOperations
          
            list = redisTemplate.opsForList(); list.rightPush(k, v); } /** * 列表获取 * * @param k * @param l * @param l1 * @return */ public List
           
          
         
        
       
      
     
    

5.然后直接在方法上打上注解

key 如果不写的话，就会根据参数来自已生成相关key,如果指定了key,就是固定的key.

【注意】缓存时间内，该方法直接跳过，不执行该方法。