加入redis

╰半橙微兮° 2022-05-12 13:18 244阅读 0赞

## POM.xml ##

<dependency>
          <groupId>redis.clients</groupId>
          <artifactId>jedis</artifactId>
          <version>2.8.1</version>
          <type>jar</type>
        </dependency>

## redis.xml 其实是spring ##

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    
        <context:property-placeholder location="classpath:redis.properties" />
    
        <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig" />
    
        <bean id="shardedJedisPool" class="redis.clients.jedis.ShardedJedisPool" scope="singleton" >
            <constructor-arg index="0" ref="jedisPoolConfig" />
            <constructor-arg index="1">
                <list>
                    <bean class="redis.clients.jedis.JedisShardInfo">
                        <constructor-arg name="host" value="${redis.host}"/>
                        <constructor-arg name="port" value="${redis.port}"/>
                        <constructor-arg name="timeout" value="${redis.timeout}"/>
                    </bean>
                </list>
            </constructor-arg>
        </bean>
    
    </beans>

## redis.properties ##

redis.host=127.0.0.1
    redis.port=6379
    redis.timeout=3000

## RedisPool.java ##

@Service("redisPool")
    @Slf4j
    public class RedisPool {
    
        @Resource(name = "shardedJedisPool")
        private ShardedJedisPool shardedJedisPool;
    
        public ShardedJedis instance() {
            return shardedJedisPool.getResource();
        }
    
        public void safeClose(ShardedJedis shardedJedis) {
            try {
               if (shardedJedis != null) {
                   shardedJedis.close();
               }
            } catch (Exception e) {
                log.error("return redis resource exception", e);
            }
        }
    }

## SysCacheService ##

@Service
    @Slf4j
    public class SysCacheService {
    
        @Resource(name = "redisPool")
        private RedisPool redisPool;
    
        public void saveCache(String toSavedValue, int timeoutSeconds, CacheKeyConstants prefix) {
            saveCache(toSavedValue, timeoutSeconds, prefix, null);
        }
    
        public void saveCache(String toSavedValue, int timeoutSeconds, CacheKeyConstants prefix, String... keys) {
            if (toSavedValue == null) {
                return;
            }
            ShardedJedis shardedJedis = null;
            try {
                String cacheKey = generateCacheKey(prefix, keys);
                shardedJedis = redisPool.instance();
                shardedJedis.setex(cacheKey, timeoutSeconds, toSavedValue);
            } catch (Exception e) {
                log.error("save cache exception, prefix:{}, keys:{}", prefix.name(), JsonMapper.obj2String(keys), e);
            } finally {
                redisPool.safeClose(shardedJedis);
            }
        }
    
        public String getFromCache(CacheKeyConstants prefix, String... keys) {
            ShardedJedis shardedJedis = null;
            String cacheKey = generateCacheKey(prefix, keys);
            try {
                shardedJedis = redisPool.instance();
                String value = shardedJedis.get(cacheKey);
                return value;
            } catch (Exception e) {
                log.error("get from cache exception, prefix:{}, keys:{}", prefix.name(), JsonMapper.obj2String(keys), e);
                return null;
            } finally {
                redisPool.safeClose(shardedJedis);
            }
        }
    
        private String generateCacheKey(CacheKeyConstants prefix, String... keys) {
            String key = prefix.name();
            if (keys != null && keys.length > 0) {
                key += "_" + Joiner.on("_").join(keys);
            }
            return key;
        }
    }

## 使用 ##

public List<SysAcl> getCurrentUserAclListFromCache() {
            int userId = RequestHolder.getCurrentUser().getId();
            String cacheValue = sysCacheService.getFromCache(CacheKeyConstants.USER_ACLS, String.valueOf(userId));
            if (StringUtils.isBlank(cacheValue)) {
                List<SysAcl> aclList = getCurrentUserAclList();
                if (CollectionUtils.isNotEmpty(aclList)) {
                    sysCacheService.saveCache(JsonMapper.obj2String(aclList), 600, CacheKeyConstants.USER_ACLS, String.valueOf(userId));
                }
                return aclList;
            }
            return JsonMapper.string2Obj(cacheValue, new TypeReference<List<SysAcl>>() {
            });
        }
    
            List<SysAcl> userAclList = getCurrentUserAclListFromCache();