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這篇“怎么使用AOP+redis+lua做限流”文章的知識(shí)點(diǎn)大部分人都不太理解,所以小編給大家總結(jié)了以下內(nèi)容,內(nèi)容詳細(xì),步驟清晰,具有一定的借鑒價(jià)值,希望大家閱讀完這篇文章能有所收獲,下面我們一起來(lái)看看這篇“怎么使用AOP+redis+lua做限流”文章吧。
公司里使用OneByOne的方式刪除數(shù)據(jù),為了防止一段時(shí)間內(nèi)刪除數(shù)據(jù)過(guò)多,讓我這邊做一個(gè)接口限流,超過(guò)一定閾值后報(bào)異常,終止刪除操作。
創(chuàng)建自定義注解
@limit
讓使用者在需要的地方配置count(一定時(shí)間內(nèi)最多訪問(wèn)次數(shù))
、period(給定的時(shí)間范圍)
,也就是訪問(wèn)頻率。然后通過(guò)LimitInterceptor
攔截方法的請(qǐng)求, 通過(guò) redis+lua 腳本的方式,控制訪問(wèn)頻率。
用于配置方法的訪問(wèn)頻率count、period
import javax.validation.constraints.Min; import java.lang.annotation.*; @Target({ElementType.METHOD, ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Inherited @Documented public @interface Limit { /** * key */ String key() default ""; /** * Key的前綴 */ String prefix() default ""; /** * 一定時(shí)間內(nèi)最多訪問(wèn)次數(shù) */ @Min(1) int count(); /** * 給定的時(shí)間范圍 單位(秒) */ @Min(1) int period(); /** * 限流的類(lèi)型(用戶(hù)自定義key或者請(qǐng)求ip) */ LimitType limitType() default LimitType.CUSTOMER; }
用于標(biāo)記參數(shù),作為redis key值的一部分
import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; @Target(ElementType.PARAMETER) @Retention(RetentionPolicy.RUNTIME) public @interface LimitKey { }
枚舉,redis key值的類(lèi)型,支持自定義key和ip、methodName中獲取key
public enum LimitType { /** * 自定義key */ CUSTOMER, /** * 請(qǐng)求者IP */ IP, /** * 方法名稱(chēng) */ METHOD_NAME; }
初始化一個(gè)限流用到的redisTemplate Bean
import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.StringRedisTemplate; import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer; import org.springframework.data.redis.serializer.StringRedisSerializer; import java.io.Serializable; @Configuration public class RedisLimiterHelper { @Bean public RedisTemplate<String, Serializable> limitRedisTemplate(@Qualifier("defaultStringRedisTemplate") StringRedisTemplate redisTemplate) { RedisTemplate<String, Serializable> template = new RedisTemplate<String, Serializable>(); template.setKeySerializer(new StringRedisSerializer()); template.setValueSerializer(new GenericJackson2JsonRedisSerializer()); template.setConnectionFactory(redisTemplate.getConnectionFactory()); return template; } }
使用 aop 的方式來(lái)攔截請(qǐng)求,控制訪問(wèn)頻率
import com.google.common.collect.ImmutableList; import com.yxt.qida.api.bean.service.xxv2.openapi.anno.Limit; import com.yxt.qida.api.bean.service.xxv2.openapi.anno.LimitKey; import com.yxt.qida.api.bean.service.xxv2.openapi.anno.LimitType; import lombok.extern.slf4j.Slf4j; import org.apache.commons.lang3.ArrayUtils; 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.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.script.DefaultRedisScript; import org.springframework.data.redis.core.script.RedisScript; import org.springframework.web.context.request.RequestContextHolder; import org.springframework.web.context.request.ServletRequestAttributes; import javax.servlet.http.HttpServletRequest; import java.io.Serializable; import java.lang.annotation.Annotation; import java.lang.reflect.Method; @Slf4j @Aspect @Configuration public class LimitInterceptor { private static final String UNKNOWN = "unknown"; private final RedisTemplate<String, Serializable> limitRedisTemplate; @Autowired public LimitInterceptor(RedisTemplate<String, Serializable> limitRedisTemplate) { this.limitRedisTemplate = limitRedisTemplate; } @Around("execution(public * *(..)) && @annotation(com.yxt.qida.api.bean.service.xxv2.openapi.anno.Limit)") public Object interceptor(ProceedingJoinPoint pjp) { MethodSignature signature = (MethodSignature) pjp.getSignature(); Method method = signature.getMethod(); Limit limitAnnotation = method.getAnnotation(Limit.class); LimitType limitType = limitAnnotation.limitType(); int limitPeriod = limitAnnotation.period(); int limitCount = limitAnnotation.count(); /** * 根據(jù)限流類(lèi)型獲取不同的key ,如果不傳我們會(huì)以方法名作為key */ String key; switch (limitType) { case IP: key = getIpAddress(); break; case CUSTOMER: key = limitAnnotation.key(); break; case METHOD_NAME: String methodName = method.getName(); key = StringUtils.upperCase(methodName); break; default: throw new RuntimeException("limitInterceptor - 無(wú)效的枚舉值"); } /** * 獲取注解標(biāo)注的 key,這個(gè)是優(yōu)先級(jí)最高的,會(huì)覆蓋前面的 key 值 */ Object[] args = pjp.getArgs(); Annotation[][] paramAnnoAry = method.getParameterAnnotations(); for (Annotation[] item : paramAnnoAry) { int paramIndex = ArrayUtils.indexOf(paramAnnoAry, item); for (Annotation anno : item) { if (anno instanceof LimitKey) { Object arg = args[paramIndex]; if (arg instanceof String && StringUtils.isNotBlank((String) arg)) { key = (String) arg; break; } } } } if (StringUtils.isBlank(key)) { throw new RuntimeException("limitInterceptor - key值不能為空"); } String prefix = limitAnnotation.prefix(); String[] keyAry = StringUtils.isBlank(prefix) ? new String[]{"limit", key} : new String[]{"limit", prefix, key}; ImmutableList<String> keys = ImmutableList.of(StringUtils.join(keyAry, "-")); try { String luaScript = buildLuaScript(); RedisScript<Number> redisScript = new DefaultRedisScript<Number>(luaScript, Number.class); Number count = limitRedisTemplate.execute(redisScript, keys, limitCount, limitPeriod); if (count != null && count.intValue() <= limitCount) { return pjp.proceed(); } else { String classPath = method.getDeclaringClass().getName() + "." + method.getName(); throw new RuntimeException("limitInterceptor - 限流被觸發(fā):" + "class:" + classPath + ", keys:" + keys + ", limitcount:" + limitCount + ", limitPeriod:" + limitPeriod + "s"); } } catch (Throwable e) { if (e instanceof RuntimeException) { throw new RuntimeException(e.getLocalizedMessage()); } throw new RuntimeException("limitInterceptor - 限流服務(wù)異常"); } } /** * lua 腳本,為了保證執(zhí)行 redis 命令的原子性 */ public String buildLuaScript() { StringBuilder lua = new StringBuilder(); lua.append("local c"); lua.append("\nc = redis.call('get',KEYS[1])"); // 調(diào)用不超過(guò)最大值,則直接返回 lua.append("\nif c and tonumber(c) > tonumber(ARGV[1]) then"); lua.append("\nreturn c;"); lua.append("\nend"); // 執(zhí)行計(jì)算器自加 lua.append("\nc = redis.call('incr',KEYS[1])"); lua.append("\nif tonumber(c) == 1 then"); // 從第一次調(diào)用開(kāi)始限流,設(shè)置對(duì)應(yīng)鍵值的過(guò)期 lua.append("\nredis.call('expire',KEYS[1],ARGV[2])"); lua.append("\nend"); lua.append("\nreturn c;"); return lua.toString(); } public String getIpAddress() { HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest(); String ip = request.getHeader("x-forwarded-for"); if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) { ip = request.getHeader("Proxy-Client-IP"); } if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) { ip = request.getHeader("WL-Proxy-Client-IP"); } if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) { ip = request.getRemoteAddr(); } return ip; } }
使用方式示例
@Limit(period = 10, count = 10) public String delUserByUrlTest(@LimitKey String token, String thirdId, String url) throws IOException { return "success"; }
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