技術標籤：redisredisehcachespring boot

@Cacheable是SpringCache的註解

當初見到這個註解以為是redis的，後來研究發現是個spring的全家桶，快取器可以使用 ehCache，Redis，ConcurrentHashMap(jvm)，ehCache研究的不多，好像和jvm記憶體一樣做不到分散式。本文就redis做自定義key過期設定

支援配置的key過期時間

採用springboot 2.4.0 版本，發現這個版本對配置檔案做了優化；比如：
配置了dev之後，dev.yml 和 dev.properties都會生效

配置檔案

# cacheName:
 
過期時間；逗號分隔
xcode.redis.cache.initialCacheNamesAndDuration=testCacheMap:15m

code

package com.jgma.xcode.redis.config;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.
 
slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.CacheManager;
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.cache.RedisCacheWriter;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import org.springframework.lang.Nullable;

import java.io.Serializable;
import java.time.Duration;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * @Author: admin
 * @GitHub https://github.com/JGMa-java/magic-code.git
 */
@Slf4j
@Configuration
public class RedisConfig {

    @Value("${xcode.redis.cache.initialCacheNamesAndDuration}")
    private String[] initialCacheNames;

    private Pattern pattern = Pattern.compile("(?:([-+]?[0-9]+)M)|(?:([-+]?[0-9]+)H)|(?:([-+]?[0-9]+)S)", Pattern.CASE_INSENSITIVE);

    private String regStr = "m|M|s|S|h|H";

    /**
     * 配置redisTemplate序列化方式,使用預設的序列化manager檢視會顯示亂碼
     */
    @Bean
    public RedisTemplate<String, Serializable> redisTemplate(LettuceConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, Serializable> template = new RedisTemplate<>();
        //使用StringRedisSerializer來序列化和反序列化redis的key值
        template.setKeySerializer(new StringRedisSerializer());

        // 使用Jackson2JsonRedisSerialize 替換預設的jdkSerializeable序列化redis的value值
        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);

        template.setValueSerializer(jackson2JsonRedisSerializer);
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }


    @Bean
    public CacheManager cacheManager(LettuceConnectionFactory connectionFactory) {

        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(connectionFactory);

        Map<String, RedisCacheConfiguration> initialCacheConfigurations = new LinkedHashMap();

        for (String initialCacheName : initialCacheNames) {
            String[] split = initialCacheName.split(":");
            String cacheName = split[0];
            String durationStr = split[1];

            Duration duration = null;
            try {
                duration = parseDuration(durationStr);
            } catch (Exception e) {
                log.error(e.getMessage());
                continue;
            }
            RedisCacheConfiguration cacheConfiguration = RedisCacheConfiguration.defaultCacheConfig().entryTtl(duration);
            initialCacheConfigurations.put(cacheName, cacheConfiguration);
        }
        RedisCacheManager redisCacheManager = RedisCacheManager.builder(redisCacheWriter).withInitialCacheConfigurations(initialCacheConfigurations).build();

        return redisCacheManager;
    }

    /**
     * 過期時間配置轉Duration,僅支援時分秒格式
     *
     * @param duration 需要匹配的配置時間；例 - 2s
     * @return
     * @throws RuntimeException 不支援的時間格式
     */
    private Duration parseDuration(@Nullable String duration) throws RuntimeException {
        Matcher matcher = pattern.matcher(duration);
        if (!matcher.matches()) {
            throw new RuntimeException("[過期時間僅支援h,s,m格式]當前引數：{" + duration + "}");
        }
        if (duration.contains("m") || duration.contains("M")) {
            return Duration.ofMinutes(Long.valueOf(duration.replaceAll(regStr, "")));
        } else if (duration.contains("s") || duration.contains("S")) {
            return Duration.ofSeconds(Long.valueOf(duration.replaceAll(regStr, "")));
        } else {
            return Duration.ofHours(Long.valueOf(duration.replaceAll(regStr, "")));
        }

    }

}

業務層

package com.jgma.xcode.redis.service;

import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

import java.util.HashMap;
import java.util.Map;

/**
 * @Author: admin
 */
@Service
public class RedisService {
    private static Map<String, String> result = new HashMap();

    static {
        result.put("1", "字串1");
        result.put("2", "字串2");
    }

    @Cacheable(key = "#key",value = "testCacheMap",cacheManager = "cacheManager")
    public Object get(String key) {
        System.out.println("我是測試cache，service返回的。。。");
        return result.get(key);
    }
}

個人感覺程式碼不是太優美，有沒有好的優化方式？？？