Spring Boot 整合Redisson实现限流

目录

    • 一、简介
    • 二、maven依赖
    • 三、编码实现
      • 3.1、配置文件
      • 3.2、配置类
      • 3.3、注解类
      • 3.4、切面类
      • 3.5、自定义异常和全局异常
      • 3.6、控制层
    • 四、验证
      • 4.1、单用户请求
      • 4.2、多用户请求
    • 结语

一、简介

  本篇文章主要来讲Spring Boot 整合 Redisson 实现限流,之前我们讲过使用Redis的Lua脚本方式,我们今天主要讲使用 Redisson 提供的方法实现限流。本文中主要用到 org.redisson.api.RRateLimiter ,它的方法比较多,比如:

  • trySetRate(RateType mode, long rate, long rateInterval, RateIntervalUnit rateIntervalUnit)
  • setRate(RateType mode, long rate, long rateInterval, RateIntervalUnit rateIntervalUnit)
  • tryAcquire()
  • tryAcquire(long permits)
  • acquire()
  • acquire(long permits)
  • tryAcquire(long timeout, TimeUnit unit)
  • tryAcquire(long permits, long timeout, TimeUnit unit)
  • RateLimiterConfig getConfig()
  • availablePermits()

二、maven依赖

pom.xml


<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.6.0version>
        <relativePath/> 
    parent>

    <groupId>com.aliangroupId>
    <artifactId>redis-limit-javaartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>redisCachename>
    <description>redis-limit-javadescription>

    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
        <project.package.directory>targetproject.package.directory>
        <java.version>1.8java.version>
        
        <jackson.version>2.9.10jackson.version>
        
        <lombok.version>1.16.14lombok.version>
        
        <fastjson.version>1.2.68fastjson.version>
        
        <junit.version>4.12junit.version>
    properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-aopartifactId>
        dependency>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-data-redisartifactId>
        dependency>

        
        <dependency>
            <groupId>org.redissongroupId>
            <artifactId>redisson-spring-boot-starterartifactId>
            <version>3.17.0version>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.bootgroupId>
                    <artifactId>spring-boot-starter-actuatorartifactId>
                exclusion>
            exclusions>
        dependency>

        
        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-databindartifactId>
            <version>${jackson.version}version>
        dependency>

        
        <dependency>
            <groupId>com.fasterxml.jackson.datatypegroupId>
            <artifactId>jackson-datatype-jsr310artifactId>
            <version>${jackson.version}version>
        dependency>

        
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>fastjsonartifactId>
            <version>${fastjson.version}version>
        dependency>

        <dependency>
            <groupId>org.apache.commonsgroupId>
            <artifactId>commons-lang3artifactId>
            <version>3.12.0version>
        dependency>

        
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <version>${lombok.version}version>
        dependency>

    dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>

project>

  因为我平常一直是使用 SpringBoot2.6.0 这个版本,它整合 redisson-spring-boot-starter 时会有点问题,本文的关键限流使用,不去深究这个问题,直接排除了健康检查就好了


<dependency>
    <groupId>org.redissongroupId>
    <artifactId>redisson-spring-boot-starterartifactId>
    <version>3.17.0version>
    <exclusions>
        <exclusion>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-actuatorartifactId>
        exclusion>
    exclusions>
dependency>

三、编码实现

3.1、配置文件

application.properties

# 端口
server.port=8090
# 上下文路径
server.servlet.context-path=/rateLimit

# Redis数据库索引(默认为0)
spring.redis.database=0
# Redis服务器地址
#spring.redis.host=192.168.0.193
spring.redis.host=127.0.0.1
# Redis服务器连接端口
spring.redis.port=6379
# Redis服务器连接密码(默认为空)
spring.redis.password=123456
# 连接池最大连接数(使用负值表示没有限制)
spring.redis.jedis.pool.max-active=20
# 连接池中的最小空闲连接
spring.redis.jedis.pool.min-idle=10
# 连接池中的最大空闲连接
spring.redis.jedis.pool.max-idle=20
# 连接池最大阻塞等待时间(使用负值表示没有限制)
spring.redis.jedis.pool.max-wait=20000
# 读时间(毫秒)
spring.redis.timeout=10000
# 连接超时时间(毫秒)
spring.redis.connect-timeout=10000

# redisson配置文件位置
spring.redis.redisson.file=classpath:redisson-single.yml

redisson-single.yml

# 单节点设置
singleServerConfig:
  # redis数据库索引
  database: 0
  # redis地址
  address: redis://127.0.0.1:6379
  # redis密码
  password: 123456
  # 连接超时
  connectTimeout: 10000
  # 读超时
  timeout: 3000
  # 命令失败重试次数
  retryAttempts: 3
  # 命令重试发送时间间隔
  retryInterval: 1500
  # 最小空闲连接数 默认24
  connectionMinimumIdleSize: 10
  # 连接池大小,默认64
  connectionPoolSize: 20

因为我本机redis是单节点的,所以是单节点配置相关的,还有很多配置,大家参照下面这两个类进行配置

  • org.redisson.config.BaseConfig
  • org.redisson.config.SingleServerConfig

如果你是集群模式,则参照下面这三个类进行配置

  • org.redisson.config.BaseConfig
  • org.redisson.config.BaseMasterSlaveServersConfig
  • org.redisson.config.ClusterServersConfig

3.2、配置类

RedisConfiguration.java

package com.alian.redissonLimit.config;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
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.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

@Slf4j
@Configuration
public class RedisConfiguration {

    /**
     * redis配置
     *
     * @param redisConnectionFactory
     * @return
     */
    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        // 实例化redisTemplate
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        //设置连接工厂
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        // key采用String的序列化
        redisTemplate.setKeySerializer(keySerializer());
        // value采用jackson序列化
        redisTemplate.setValueSerializer(valueSerializer());
        // Hash key采用String的序列化
        redisTemplate.setHashKeySerializer(keySerializer());
        // Hash value采用jackson序列化
        redisTemplate.setHashValueSerializer(valueSerializer());
        //执行函数,初始化RedisTemplate
        redisTemplate.afterPropertiesSet();
        return redisTemplate;
    }

    /**
     * key类型采用String序列化
     *
     * @return
     */
    private RedisSerializer<String> keySerializer() {
        return new StringRedisSerializer();
    }

    /**
     * value采用JSON序列化
     *
     * @return
     */
    private RedisSerializer<Object> valueSerializer() {
        //设置jackson序列化
        Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<>(Object.class);
        //设置序列化对象
        jackson2JsonRedisSerializer.setObjectMapper(getMapper());
        return jackson2JsonRedisSerializer;
    }


    /**
     * 使用com.fasterxml.jackson.databind.ObjectMapper
     * 对数据进行处理包括java8里的时间
     *
     * @return
     */
    private ObjectMapper getMapper() {
        ObjectMapper mapper = new ObjectMapper();
        //设置可见性
        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        //默认键入对象
        mapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        //设置Java 8 时间序列化
        JavaTimeModule timeModule = new JavaTimeModule();
        timeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        timeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        timeModule.addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern("HH:mm:ss")));
        timeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        timeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        timeModule.addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern("HH:mm:ss")));
        //禁用把时间转为时间戳
        mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        mapper.registerModule(timeModule);
        return mapper;
    }

}

提过很多次了,就是Redis的整合。

3.3、注解类

RateLimiter.java

package com.alian.redissonLimit.annotate;

import org.redisson.api.RateType;

import java.lang.annotation.*;

@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface RedissonRateLimiter {

    /**
     * RRateLimiter 限流模式
     * OVERALL     所有客户端加总限流
     * PER_CLIENT  每个客户端单独计算流量
     */
    RateType mode() default RateType.PER_CLIENT;

    /**
     * Spel表达式
     */
    String[] keys() default {};

    /**
     * 单位时间产生的令牌数,默认100
     */
    long rate() default 100;

    /**
     * 时间间隔,默认1秒
     */
    long rateInterval() default 1;

    /**
     * 拒绝请求时的提示信息
     */
    String showPromptMsg() default "服务器繁忙,请稍候再试";

}

  自定义注解也没有什么好说的,主要是定义了:@RateLimiter

  • 限流模式 mode (全局限流和单机限流)
  • key的名称 keys ,用于Redis锁的键
  • 单位时间产生的令牌数 rate ,默认100
  • 时间间隔 rateInterval ,默认1秒
  • 限流时返回给前端的提示信息 showPromptMsg

3.4、切面类

RateLimiterAspectHandler.java

package com.alian.redissonLimit.aop;

import com.alian.redissonLimit.annotate.RedissonRateLimiter;
import com.alian.redissonLimit.annotate.RedissonRateLimiters;
import com.alian.redissonLimit.exception.RateLimiterException;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.reflect.MethodSignature;
import org.redisson.api.RRateLimiter;
import org.redisson.api.RateIntervalUnit;
import org.redisson.api.RedissonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.DigestUtils;

import java.nio.charset.StandardCharsets;
import java.util.concurrent.TimeUnit;

@Slf4j
@Component
@Aspect
public class RateLimiterAspectHandler {

    @Autowired
    private RateLimiterKeyProvider keyProvider;

    @Autowired
    private RedissonClient redissonClient;

    @Around(value = "@annotation(redissonRateLimiter)", argNames = "point,redissonRateLimiter")
    public Object around(ProceedingJoinPoint point, RedissonRateLimiter redissonRateLimiter) throws Throwable {
        isAllow(point, redissonRateLimiter);
        return point.proceed();
    }

    @Around(value = " @annotation(redissonRateLimiters)", argNames = "point,redissonRateLimiters")
    public Object around(ProceedingJoinPoint point, RedissonRateLimiters redissonRateLimiters) throws Throwable {
        RedissonRateLimiter[] limiters = redissonRateLimiters.value();
        for (RedissonRateLimiter rateLimiter : limiters) {
            isAllow(point, rateLimiter);
        }
        return point.proceed();
    }

    private void isAllow(ProceedingJoinPoint point, RedissonRateLimiter redissonRateLimiter) {
        // 获取key
        String key = keyProvider.getKey(point, redissonRateLimiter);
        // 此处是为了日志输出
        boolean flag = StringUtils.isNotBlank(key);
        // 类路径+方法,然后计算md5
        String uniqueKey = getUniqueKey((MethodSignature) point.getSignature());
        // key名称
        key = StringUtils.isNotBlank(key) ? uniqueKey + "." + key : uniqueKey;
        // 获取RRateLimiter实例
        RRateLimiter limiter = redissonClient.getRateLimiter(key);
        // 创建令牌桶数据模型,单位时间内产生多少令牌
        limiter.trySetRate(redissonRateLimiter.mode(), redissonRateLimiter.rate(), redissonRateLimiter.rateInterval(), RateIntervalUnit.SECONDS);
        // 尝试访问数据,timeout 时间内,允许获得的数量permits(如果获取失败,返回false)
        // 单位时间内不能获取到1个令牌,则返回,不阻塞
        boolean tryAcquire = limiter.tryAcquire(1, redissonRateLimiter.rateInterval(), TimeUnit.SECONDS);
        log.info("【{}】请求,线程:【{}】,获取令牌的结果:{}", flag ? "单用户" : "多用户", Thread.currentThread().getName(), tryAcquire);
        if (!tryAcquire) {
            log.error("限流模式:{}; 限流数量:{}; 限流时间间隔:{}",
                    redissonRateLimiter.mode().toString(), redissonRateLimiter.rate(), redissonRateLimiter.rateInterval());
            throw new RateLimiterException(redissonRateLimiter.showPromptMsg());
        }
    }

    private String getUniqueKey(MethodSignature signature) {
        String format = String.format("%s.%s", signature.getDeclaringTypeName(), signature.getMethod().getName());
        return DigestUtils.md5DigestAsHex(format.getBytes(StandardCharsets.UTF_8));
    }

}
  • 切面是针对所有使用了@RateLimiter 注解的方法
  • 首先是获取定义的key的值,这里通过 RateLimiterKeyProvider 获取到
  • 获取一个方法的唯一值作为Redis中key的一部分(md5(类路径+方法名)),和key一起确定最后的key
  • 通过 RedissonClient 获取RRateLimiter 实例
  • 创建令牌桶数据模型,单位时间内生成多少令牌
  • timeout 秒内不能获取到 permits 个令牌,获取到则返回 true ,否则返回 false
  • 如果未获取到则抛出异常(限流了),做一个全局异常捕获,统一返回处理

我们这里的两个方法:

  • trySetRate() :初始化RateLimit的状态并将配置存储到Redis服务器
  • tryAcquire() :仅当所有许可证在给定等待时间内可用时,才获取给定数量的许可证。如果有许可证,则获取许可证,返回true,并将可用许可证的数量减少一个。如果没有可用的许可,则此方法将立即返回值false。

RateLimiterKeyProvider.java

package com.alian.redissonLimit.aop;

import com.alian.redissonLimit.annotate.RedissonRateLimiter;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.context.expression.MethodBasedEvaluationContext;
import org.springframework.core.DefaultParameterNameDiscoverer;
import org.springframework.core.ParameterNameDiscoverer;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

@Slf4j
@Component
public class RateLimiterKeyProvider {

    private ParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();

    private ExpressionParser parser = new SpelExpressionParser();

    public String getKey(JoinPoint joinPoint, RedissonRateLimiter redissonRateLimiter) {
        List<String> keyList = new ArrayList<>();
        Method method = getMethod(joinPoint);
        List<String> definitionKeys = getSpelDefinitionKey(redissonRateLimiter.keys(), method, joinPoint.getArgs());
        keyList.addAll(definitionKeys);
        return StringUtils.collectionToDelimitedString(keyList,".","","");
    }

    private Method getMethod(JoinPoint joinPoint) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        if (method.getDeclaringClass().isInterface()) {
            try {
                method = joinPoint.getTarget().getClass().getDeclaredMethod(signature.getName(),
                        method.getParameterTypes());
            } catch (Exception e) {
                log.error(null,e);
            }
        }
        return method;
    }

    private List<String> getSpelDefinitionKey(String[] definitionKeys, Method method, Object[] parameterValues) {
        List<String> definitionKeyList = new ArrayList<>();
        for (String definitionKey : definitionKeys) {
            if (definitionKey != null && !definitionKey.isEmpty()) {
                EvaluationContext context = new MethodBasedEvaluationContext(null, method, parameterValues, discoverer);
                String key = parser.parseExpression(definitionKey).getValue(context).toString();
                definitionKeyList.add(key);
            }
        }
        return definitionKeyList;
    }
}

3.5、自定义异常和全局异常

RateLimiterException.java

package com.alian.redissonLimit.exception;

public class RateLimiterException extends RuntimeException {

    public RateLimiterException(String message) {
        super(message);
    }

}

  自定义异常类,也没啥好说的,下面就是全局异常,为了省篇幅没有把所有的异常都列出来,小伙伴可以自行添加,主要是对我们RateLimiterException 进行处理。

GlobalExceptionHandler.java

package com.alian.redissonLimit.exception;

import com.alian.redissonLimit.dto.ApiResponseDto;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;

import javax.servlet.http.HttpServletRequest;

@Slf4j
@Component
@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler
    @ResponseBody
    @ResponseStatus(HttpStatus.OK)
    public ApiResponseDto<?> handle(HttpRequestMethodNotSupportedException exception, HttpServletRequest request) {
        return logWarn(request.getRequestURI() + " " + exception.getMessage(), null, ApiResponseDto.errRequestMethod("请求方法错误"));
    }

    @ExceptionHandler
    @ResponseBody
    @ResponseStatus(HttpStatus.OK)
    public ApiResponseDto handle(MissingServletRequestParameterException exception) {
        return logWarn(exception.getMessage(), null, ApiResponseDto.errParam("参数错误"));
    }

    @ExceptionHandler
    @ResponseBody
    @ResponseStatus(HttpStatus.OK)
    public ApiResponseDto handle(RateLimiterException exception) {
        return ApiResponseDto.fail(exception.getMessage());
    }

    @ExceptionHandler
    @ResponseBody
    @ResponseStatus(HttpStatus.OK)
    public ApiResponseDto handle(Exception exception) {
        log.info("异常类:{}", exception.getClass().getCanonicalName());
        return logError(null, exception, ApiResponseDto.exception("系统异常"));
    }

    private static ApiResponseDto logWarn(String msg, Exception e, ApiResponseDto responseDto) {
        long timestamp = responseDto.getTimestamp();
        String m = "timestamp is " + timestamp;
        if (msg != null) {
            m += ", " + msg;
        }
        if (e == null) {
            log.warn(m);
        } else {
            log.warn(m, e);
        }
        return responseDto;
    }

    private static ApiResponseDto logError(String msg, Exception e, ApiResponseDto responseDto) {
        long timestamp = responseDto.getTimestamp();
        String m = "timestamp is " + timestamp;
        if (msg != null) {
            m += ", " + msg;
        }
        log.error(m, e);
        return responseDto;
    }

}

对应的统一返回封装如下:

ApiResponseDto.java

package com.alian.redissonLimit.dto;

import lombok.*;
import lombok.experimental.Accessors;

@Setter
@Getter
@Accessors(chain = true)
@NoArgsConstructor
@AllArgsConstructor
@ToString(exclude = "content")
public class ApiResponseDto<T> {

    /** 成功 */
    public static String CODE_SUCCESS="0000";
    /** 失败 */
    public static String CODE_FAIL="1000";
    /** 系统异常 */
    public static String CODE_EXCEPTION="1001";
    /** 签名错误 */
    public static String CODE_ERR_SIGN="1002";
    /** 参数错误 */
    public static String CODE_ERR_PARAM="1003";
    /** 业务异常 */
    public static String CODE_BIZ_ERR="1004";
    /** 查询无数据,使用明确的参数(如id)进行查询时未找到记录时返回此错误码 */
    public static String CODE_NO_DATA="1005";
    /** 错误的请求方法 */
    public static String CODE_ERR_REQUEST_METHOD="1006";
    /** 错误的请求内容类型 */
    public static String CODE_ERR_CONTENT_TYPE="1007";
    /** 系统繁忙 */
    public static String CODE_SYS_BUSY="1008";
    /** 显示提示 */
    public static String CODE_SHOW_TIP="1009";
    /** 根据bizCode进行处理 */
    public static String CODE_DEAL_BIZ_CODE="1012";
    /** 未找到请求 */
    public static String CODE_NOT_FOUND_CODE="1013";

    public final static ApiResponseDto SUCCESS=new ApiResponseDto();


    private String code =CODE_SUCCESS;

    /** 状态说明 */
    private String msg ="success";

    /** 请求是否成功 */
    public boolean isSuccess(){
        return CODE_SUCCESS.equals(code);
    }

    /** 结果内容 */
    private T content;

    /** 时间戳 */
    private long timestamp=System.currentTimeMillis();

    /** 业务状态码,由业务接口定义 */
    private String bizCode;

    /** 业务状态说明 */
    private String bizMsg;

    public ApiResponseDto(T content) {
        this.content=content;
    }

    public static <T> ApiResponseDto<T> success(){
        return SUCCESS;
    }

    public static <T> ApiResponseDto<T> success(T content){
        return new ApiResponseDto<T>(content);
    }

    public static <T> ApiResponseDto<T> fail(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_FAIL);
        response.setMsg(msg);
        return response;
    }

    public static <T> ApiResponseDto<T> exception(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_EXCEPTION);
        response.setMsg(msg);
        return response;
    }

    public static <T> ApiResponseDto<T> errSign(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_ERR_SIGN);
        response.setMsg(msg);
        return response;
    }

    public static <T> ApiResponseDto<T> errParam(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_ERR_PARAM);
        response.setMsg(msg);
        return response;
    }

    public static <T> ApiResponseDto<T> bizErr(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_BIZ_ERR);
        response.setMsg(msg);
        return response;
    }

    public static <T> ApiResponseDto<T> notFound(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_NOT_FOUND_CODE);
        response.setMsg(msg);
        return response;
    }

    public static <T> ApiResponseDto<T> noData(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_NO_DATA);
        response.setMsg(msg);
        return response;
    }
    public static <T> ApiResponseDto<T>  errRequestMethod(String msg){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_ERR_REQUEST_METHOD);
        response.setMsg(msg);
        return response;
    }
    public static <T> ApiResponseDto<T> errContentType(){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_ERR_CONTENT_TYPE);
        response.setMsg("错误的请求内容类型");
        return response;
    }
    public static <T> ApiResponseDto<T> sysBusy(){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_SYS_BUSY);
        response.setMsg("系统繁忙");
        return response;
    }
    public static <T> ApiResponseDto<T>  showTip(String tip){
        ApiResponseDto<T> response = new ApiResponseDto<>();
        response.setCode(CODE_SHOW_TIP);
        response.setMsg(tip);
        return response;
    }

    public ApiResponseDto<T> bizInfo(String bizCode,String bizMsg){
        this.code=bizCode;
        this.msg=bizMsg;
        return this;
    }

    public static <T> ApiResponseDto<T>  dealBizCode(String bizCode,String bizMsg,T content){
        ApiResponseDto<T> response = new ApiResponseDto<>(content);
        response.setCode(CODE_DEAL_BIZ_CODE);
        response.setMsg("根据bizCode进行处理");
        response.setBizCode(bizCode);
        response.setBizMsg(bizMsg);
        return response;
    }
}

3.6、控制层

UserController.java

package com.alian.redissonLimit.controller;

import com.alian.redissonLimit.annotate.RedissonRateLimiter;
import com.alian.redissonLimit.annotate.RedissonRateLimiters;
import com.alian.redissonLimit.dto.ApiResponseDto;
import com.alian.redissonLimit.dto.UserDto;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RateType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.time.LocalDateTime;
import java.util.HashMap;
import java.util.Map;

@Slf4j
@RequestMapping("/user")
@RestController
public class UserController {

    private static Map<String, UserDto> map = new HashMap<String, UserDto>() {{
        put("BAT001", new UserDto("BAT001", "梁南生", 27, "研发部", 18000.0, LocalDateTime.of(2020, 5, 20, 9, 0, 0)));
        put("BAT002", new UserDto("BAT002", "包雅馨", 25, "财务部", 8800.0, LocalDateTime.of(2016, 11, 10, 8, 30, 0)));
        put("BAT003", new UserDto("BAT003", "罗考聪", 35, "测试部", 6400.0, LocalDateTime.of(2017, 3, 20, 14, 0, 0)));
    }};

    @RedissonRateLimiters(value = {
            @RedissonRateLimiter(keys = {"#id"}, mode = RateType.OVERALL, rate = 1, rateInterval = 1, showPromptMsg = "您查询太快了,请稍后再试"),
            @RedissonRateLimiter(mode = RateType.OVERALL, rate = 3, rateInterval = 1, showPromptMsg = "系统繁忙,请稍后再试")
    })
    @RequestMapping("/findById/{id}")
    public ApiResponseDto<UserDto> findById(@PathVariable("id") String id) {
        UserDto userDto = map.getOrDefault(id, null);
        if (userDto != null) {
            return ApiResponseDto.success(userDto);
        }
        return ApiResponseDto.noData("未查询到数据");
    }

}

  简单模拟根据用户编号查询用户的接口,关键是我们使用注解@RateLimiter 的方法可以做限流,看是否能达到我们的要求。这里有两层意思:

  • 一个用户每秒最多获取1个令牌,每秒最多生成1个令牌
  • 整个接口每秒最多获取3个令牌,每秒最多生成1个令牌

  虽说和我们上一篇的设计是一样的,但是得到的结果可能就不一样了,具体的我们来看看测试结果,然后了解下为啥可能会不一样。

四、验证

4.1、单用户请求

  写个简单的单元测试方法。

测试方法

package com.alian.redissonLimit;

import com.alian.redissonLimit.controller.UserController;
import com.alian.redissonLimit.dto.ApiResponseDto;
import com.alian.redissonLimit.dto.UserDto;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.concurrent.CountDownLatch;

@Slf4j
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class RedisLimitTest {

    @Autowired
    private UserController userController;

    @Test
    public void singleUserRequest() {
        final CountDownLatch countDownLatch = new CountDownLatch(5);
        for (int i = 0; i < 5; i++) {
            new Thread(() -> {
                try {
                    // 使当前线程在锁存器倒计数至零之前一直等待,除非线程被中断或超出了指定的等待时间。如果当前计数为零,则此方法立刻返回true值
                    countDownLatch.await();
                    //获得锁
                    ApiResponseDto<UserDto> responseDto = userController.findById("BAT001");
                    log.info("线程【{}】执行完,结果信息:{}", Thread.currentThread().getName(), responseDto.getMsg());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }, "Thread" + i).start();
            // 递减锁存器的计数,如果计数到达零,则释放所有等待的线程。如果当前计数大于零,则将计数减少.
            countDownLatch.countDown();
        }
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

}

单用户后台结果1:

11:39:17 953 INFO [Thread3]:【单用户】请求,线程:【Thread3】,获取令牌的结果:true
11:39:17 953 INFO [Thread3]:【多用户】请求,线程:【Thread3】,获取令牌的结果:true
11:39:17 963 INFO [Thread3]:线程【Thread3】执行完,结果信息:success
11:39:18 969 INFO [Thread2]:【单用户】请求,线程:【Thread2】,获取令牌的结果:false
11:39:18 969 INFO [Thread1]:【单用户】请求,线程:【Thread1】,获取令牌的结果:false
11:39:18 969 INFO [Thread4]:【单用户】请求,线程:【Thread4】,获取令牌的结果:false
11:39:18 969 INFO [Thread0]:【单用户】请求,线程:【Thread0】,获取令牌的结果:false
11:39:18 969 ERROR [Thread1]:限流模式:OVERALL; 限流数量:1; 限流时间间隔:1
11:39:18 969 ERROR [Thread4]:限流模式:OVERALL; 限流数量:1; 限流时间间隔:1
11:39:18 969 ERROR [Thread2]:限流模式:OVERALL; 限流数量:1; 限流时间间隔:1
11:39:18 969 ERROR [Thread0]:限流模式:OVERALL; 限流数量:1; 限流时间间隔:1

从上面的结果我们可以看到同时1秒内同时接收5个请求,只有1个请求拿到了令牌,我们之前就说了,可能结果还能不同,我们这里的间隔是1秒钟,但是如果我们把获取令牌的时间改成2秒呢?

boolean tryAcquire = limiter.tryAcquire(1, redissonRateLimiter.rateInterval(), TimeUnit.SECONDS);

如果改成

boolean tryAcquire = limiter.tryAcquire(1, 2, TimeUnit.SECONDS);

单用户后台结果2:

13:19:43 617 INFO [Thread4]:【单用户】请求,线程:【Thread4】,获取令牌的结果:true
13:19:43 623 INFO [Thread4]:线程【Thread4】执行完,结果信息:success
13:19:44 627 INFO [Thread3]:【单用户】请求,线程:【Thread3】,获取令牌的结果:true
13:19:44 627 INFO [Thread3]:线程【Thread3】执行完,结果信息:success
13:19:45 617 INFO [Thread1]:【单用户】请求,线程:【Thread1】,获取令牌的结果:false
13:19:45 617 INFO [Thread0]:【单用户】请求,线程:【Thread0】,获取令牌的结果:false
13:19:45 617 INFO [Thread2]:【单用户】请求,线程:【Thread2】,获取令牌的结果:false
13:19:45 617 ERROR [Thread1]:限流模式:OVERALL; 限流数量:1; 限流时间间隔:1
13:19:45 617 ERROR [Thread2]:限流模式:OVERALL; 限流数量:1; 限流时间间隔:1
13:19:45 617 ERROR [Thread0]:限流模式:OVERALL; 限流数量:1; 限流时间间隔:1

  从这里我们可以看到单用户请求5次,最后有2个拿到了令牌,tryAcquire(1, 2, TimeUnit.SECONDS),这个意思就是在2秒内获取1个令牌即可,虽说第一秒只有1个令牌,但是到第二秒内又产生了1个令牌,所以5个请求,有2个请求拿到了令牌。其实这种也有一定的好处,就是先请求进来的,有一定的概率会分配到锁,也就是先到先得的概率大一点,类似在排队一样。

4.2、多用户请求

  我们还是把上面的修改,改回去(tryAcquire(1, redissonRateLimiter.rateInterval(), TimeUnit.SECONDS))。

测试方法

package com.alian.redissonLimit;

import com.alian.redissonLimit.controller.UserController;
import com.alian.redissonLimit.dto.ApiResponseDto;
import com.alian.redissonLimit.dto.UserDto;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.concurrent.CountDownLatch;

@Slf4j
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class RedisLimitTest {

    @Autowired
    private UserController userController;

    @Test
    public void multiUserRequest() {
        final CountDownLatch countDownLatch = new CountDownLatch(5);
        for (int i = 1; i < 6; i++) {
            String id = "BAT00" + i;
            new Thread(() -> {
                try {
                    // 使当前线程在锁存器倒计数至零之前一直等待,除非线程被中断或超出了指定的等待时间。如果当前计数为零,则此方法立刻返回true值
                    countDownLatch.await();
                    //获得锁
                    ApiResponseDto<UserDto> responseDto = userController.findById(id);
                    log.info("线程【{}】执行完,结果信息:{}", Thread.currentThread().getName(), responseDto.getMsg());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }, "Thread" + i).start();
            // 递减锁存器的计数,如果计数到达零,则释放所有等待的线程。如果当前计数大于零,则将计数减少.
            countDownLatch.countDown();
        }
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

}

  我们测试方法是5个用户,5个线程同时请求我们的接口,所以单用户限流都是能拿到令牌的,5个请求都拿到了令牌,而接口限流是每秒3个令牌,所以有2个触发了限流。

单用户后台结果1:

13:38:02 763 INFO [Thread4]:【单用户】请求,线程:【Thread4】,获取令牌的结果:true
13:38:02 763 INFO [Thread1]:【单用户】请求,线程:【Thread1】,获取令牌的结果:true
13:38:02 763 INFO [Thread2]:【单用户】请求,线程:【Thread2】,获取令牌的结果:true
13:38:02 763 INFO [Thread5]:【单用户】请求,线程:【Thread5】,获取令牌的结果:true
13:38:02 763 INFO [Thread3]:【单用户】请求,线程:【Thread3】,获取令牌的结果:true
13:38:02 764 INFO [Thread5]:【多用户】请求,线程:【Thread5】,获取令牌的结果:true
13:38:02 764 INFO [Thread4]:【多用户】请求,线程:【Thread4】,获取令牌的结果:true
13:38:02 764 INFO [Thread2]:【多用户】请求,线程:【Thread2】,获取令牌的结果:true
13:38:02 768 INFO [Thread5]:线程【Thread5】执行完,结果信息:未查询到数据
13:38:02 768 INFO [Thread2]:线程【Thread2】执行完,结果信息:success
13:38:02 768 INFO [Thread4]:线程【Thread4】执行完,结果信息:未查询到数据
13:38:03 777 INFO [Thread1]:【多用户】请求,线程:【Thread1】,获取令牌的结果:false
13:38:03 777 INFO [Thread3]:【多用户】请求,线程:【Thread3】,获取令牌的结果:false
13:38:03 777 ERROR [Thread1]:限流模式:OVERALL; 限流数量:3; 限流时间间隔:1
13:38:03 777 ERROR [Thread3]:限流模式:OVERALL; 限流数量:3; 限流时间间隔:1

  从结果上可以看出,先是用户限流执行,然后接口限流执行。其实这里还和我们的注解顺序有关系,如果我们把com.alian.redissonLimit.controller findById 方法上面的组合注解

@RedissonRateLimiters(value = {
        @RedissonRateLimiter(keys = {"#id"}, mode = RateType.OVERALL, rate = 1, rateInterval = 1, showPromptMsg = "您查询太快了,请稍后再试"),
        @RedissonRateLimiter(mode = RateType.OVERALL, rate = 3, rateInterval = 1, showPromptMsg = "系统繁忙,请稍后再试")
})

改成(注解顺序改变

@RedissonRateLimiters(value = {
        @RedissonRateLimiter(mode = RateType.OVERALL, rate = 3, rateInterval = 1, showPromptMsg = "系统繁忙,请稍后再试"),
        @RedissonRateLimiter(keys = {"#id"}, mode = RateType.OVERALL, rate = 1, rateInterval = 1, showPromptMsg = "您查询太快了,请稍后再试")
})

单用户后台结果2:

13:40:18 786 INFO [Thread3]:【多用户】请求,线程:【Thread3】,获取令牌的结果:true
13:40:18 786 INFO [Thread5]:【多用户】请求,线程:【Thread5】,获取令牌的结果:true
13:40:18 786 INFO [Thread4]:【多用户】请求,线程:【Thread4】,获取令牌的结果:true
13:40:18 805 INFO [Thread4]:【单用户】请求,线程:【Thread4】,获取令牌的结果:true
13:40:18 805 INFO [Thread5]:【单用户】请求,线程:【Thread5】,获取令牌的结果:true
13:40:18 805 INFO [Thread3]:【单用户】请求,线程:【Thread3】,获取令牌的结果:true
13:40:18 807 INFO [Thread4]:线程【Thread4】执行完,结果信息:未查询到数据
13:40:18 807 INFO [Thread3]:线程【Thread3】执行完,结果信息:success
13:40:18 807 INFO [Thread5]:线程【Thread5】执行完,结果信息:未查询到数据
13:40:19 797 INFO [Thread2]:【多用户】请求,线程:【Thread2】,获取令牌的结果:false
13:40:19 797 INFO [Thread1]:【多用户】请求,线程:【Thread1】,获取令牌的结果:false
13:40:19 797 ERROR [Thread2]:限流模式:OVERALL; 限流数量:3; 限流时间间隔:1
13:40:19 797 ERROR [Thread1]:限流模式:OVERALL; 限流数量:3; 限流时间间隔:1

  从结果上可以看出,先是接口限流执行,然后用户限流执行,和之前的执行顺序相比就是相反的了。

结语

  • 使用 @RateLimiters 组合注解可以完成单用户限流和多用户接口限流
  • 使用 @RateLimiters 组合注解时,需要注意子注解 @RateLimiter 的顺序
  • 使用 Redisson 实现限流时,它是支持集群模式的
  • 使用 Redisson 实现限流调用方式比较简单,但是底层还是使用的Lua脚本
  • 使用 Redisson 实现限流的时,获取令牌的时间可以根据具体情况灵活调整
  • 使用 Redisson 实现限流的时,有个不好的地方是它生成的key不会自动过期,需要配合redis删除策略或者手动清除
  • 使用 Redisson 实现限流的时,通过类型或者方法名预先配置好指定的规则并且缓存起来,使用时再获取,可以达到动态配置的效果

  所以还是建议使用我之前介绍的采用Lua脚本:Spring Boot 整合Redis使用Lua脚本实现限流

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