文章链接：liuyueyi.github.io/hexblog/201…

Spring之借助Redis设计一个简单访问计数器

为什么要做一个访问计数？之前的个人博客用得是卜算子做站点访问计数，用起来挺好，但出现较多次的响应很慢，再其次就是个人博客实在是访问太少，数据不好看😢…

前面一篇博文简单介绍了Spring中的RedisTemplate的配置与使用，那么这篇算是一个简单的应用case了,主要基于Redis的计数器来实现统计

I. 设计

一个简单的访问计数器，主要利用redis的hash结构，对应的存储结构如下:

存储结构比较简单，为了扩展，每个应用（or站点）对应一个APP，然后根据path路径进行分页统计，最后有一个特殊的用于统计全站的访问计数

II. 实现

主要就是利用Redis的hash结构，然后实现数据统计，并没有太多的难度，Spring环境下搭建redis环境可以参考:

• 180611-Spring之RedisTemplate配置与使用

1. Redis封装类

针对几个常用的做了简单的封装，直接使用RedisTemplate的excute方法进行的操作，当然也是可以使用 template.opsForValue() 等便捷方式，这里采用JSON方式进行对象的序列化和反序列化

public class QuickRedisClient {
    private static final Charset CODE = Charset.forName("UTF-8");
    private static RedisTemplate<String, String> template;

    public static void register(RedisTemplate<String, String> template) {
        QuickRedisClient.template = template;
    }

    public static void nullCheck(Object... args) {
        for (Object obj : args) {
            if (obj == null) {
                throw new IllegalArgumentException("redis argument can not be null!");
            }
        }
    }

    public static byte[] toBytes(String key) {
        nullCheck(key);
        return key.getBytes(CODE);
    }

    public static byte[][] toBytes(List<String> keys) {
        byte[][] bytes = new byte[keys.size()][];
        int index = 0;
        for (String key : keys) {
            bytes[index++] = toBytes(key);
        }
        return bytes;
    }

    public static String getStr(String key) {
        return template.execute((RedisCallback<String>) con -> {
            byte[] val = con.get(toBytes(key));
            return val == null ? null : new String(val);
        });
    }

    public static void putStr(String key, String value) {
        template.execute((RedisCallback<Void>) con -> {
            con.set(toBytes(key), toBytes(value));
            return null;
        });
    }

    public static Long incr(String key, long add) {
        return template.execute((RedisCallback<Long>) con -> {
            Long record = con.incrBy(toBytes(key), add);
            return record == null ? 0L : record;
        });
    }

    public static Long hIncr(String key, String field, long add) {
        return template.execute((RedisCallback<Long>) con -> {
            Long record = con.hIncrBy(toBytes(key), toBytes(field), add);
            return record == null ? 0L : record;
        });
    }

    public static <T> T hGet(String key, String field, Class<T> clz) {
        return template.execute((RedisCallback<T>) con -> {
            byte[] records = con.hGet(toBytes(key), toBytes(field));
            if (records == null) {
                return null;
            }

            return JSON.parseObject(records, clz);
        });
    }

    public static <T> Map<String, T> hMGet(String key, List<String> fields, Class<T> clz) {
        List<byte[]> list =
                template.execute((RedisCallback<List<byte[]>>) con -> con.hMGet(toBytes(key), toBytes(fields)));
        if (CollectionUtils.isEmpty(list)) {
            return Collections.emptyMap();
        }

        Map<String, T> result = new HashMap<>();
        for (int i = 0; i < fields.size(); i++) {
            if (list.get(i) == null) {
                continue;
            }

            result.put(fields.get(i), JSON.parseObject(list.get(i), clz));
        }
        return result;
    }
}

对应的配置类

package com.git.hui.story.cache.redis;

import com.git.hui.story.cache.redis.serializer.DefaultStrSerializer;
import org.springframework.cache.CacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.connection.RedisPassword;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;

/**
 * Created by yihui in 18:45 18/6/11.
 */
@Configuration
@PropertySource(value = "classpath:application.yml")
public class RedisConf {

    private final Environment environment;

    public RedisConf(Environment environment) {
        this.environment = environment;
    }

    @Bean
    public CacheManager cacheManager() {
        return RedisCacheManager.RedisCacheManagerBuilder.fromConnectionFactory(redisConnectionFactory()).build();
    }

    @Bean
    public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, String> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);

        DefaultStrSerializer serializer = new DefaultStrSerializer();
        redisTemplate.setValueSerializer(serializer);
        redisTemplate.setHashValueSerializer(serializer);
        redisTemplate.setKeySerializer(serializer);
        redisTemplate.setHashKeySerializer(serializer);

        redisTemplate.afterPropertiesSet();

        QuickRedisClient.register(redisTemplate);
        return redisTemplate;
    }


    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        LettuceConnectionFactory fac = new LettuceConnectionFactory();
        fac.getStandaloneConfiguration().setHostName(environment.getProperty("spring.redis.host"));
        fac.getStandaloneConfiguration().setPort(Integer.parseInt(environment.getProperty("spring.redis.port")));
        fac.getStandaloneConfiguration()
                .setPassword(RedisPassword.of(environment.getProperty("spring.redis.password")));
        fac.afterPropertiesSet();
        return fac;
    }
}

2. Controller 支持

首先是定义请求参数:

@Data
public class WebCountReqDO implements Serializable {
    private String appKey;
    private String referer;
}

其次是实现Controller接口，稍稍注意下，根据path进行计数的逻辑：

• 如果请求参数显示指定了referer参数，则用传入的参数进行统计
• 如果没有显示指定referer，则根据header获取referer
• 解析referer，分别对path和host进行统计+1，这样站点的统计计数就是根据host来的，而页面的统计计数则是根据path路径来的

@Slf4j
@RestController
@RequestMapping(path = "/count")
public class WebCountController {

    @RequestMapping(path = "cc", method = {RequestMethod.GET})
    public ResponseWrapper<CountDTO> addCount(WebCountReqDO webCountReqDO) {
        String appKey = webCountReqDO.getAppKey();
        if (StringUtils.isBlank(appKey)) {
            return ResponseWrapper.errorReturnMix(Status.StatusEnum.ILLEGAL_PARAMS_MIX, "请指定APPKEY!");
        }

        String referer = ReqInfoContext.getReqInfo().getReferer();
        if (StringUtils.isBlank(referer)) {
            referer = webCountReqDO.getReferer();
        }

        if (StringUtils.isBlank(referer)) {
            return ResponseWrapper.errorReturnMix(Status.StatusEnum.FAIL_MIX, "无法获取请求referer!");
        }

        return ResponseWrapper.successReturn(doUpdateCnt(appKey, referer));
    }


    private CountDTO doUpdateCnt(String appKey, String referer) {
        try {
            if (!referer.startsWith("http")) {
                referer = "https://" + referer;
            }

            URI uri = new URI(referer);
            String host = uri.getHost();
            String path = uri.getPath();
            long count = QuickRedisClient.hIncr(appKey, path, 1);
            long total = QuickRedisClient.hIncr(appKey, host, 1);
            return new CountDTO(count, total);
        } catch (Exception e) {
            log.error("get referer path error! referer: {}, e: {}", referer, e);
            return new CountDTO(1L, 1L);
        }
    }
}

3. 实例

针对这个简单的redis计数，目前在个人的mweb和zweb两个页面已经接入，在页脚处可以看到对应的计数，每次刷新计数会+1

• mweb: liuyueyi.gitee.io/mweb/#/
• zweb: liuyueyi.gitee.io/zweb/#/

III. 其他

0. 相关博文

• 180611-Spring之RedisTemplate配置与使用

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