java 单机接口限流处理方案
348
2022-06-06
这篇文章主要介绍了Spring boot通过AOP防止API重复请求代码实例,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
实现思路
基于Spring Boot 2.x
自定义注解,用来标记是哪些API是需要监控是否重复请求
通过Spring AOP来切入到Controller层,进行监控
检验重复请求的Key:Token + ServletPath + SHA1RequestParas
使用以上三个参数拼接的Key作为去判断是否重复请求
由于项目是基于集群的,使用Redis存储Key,而且redis的特性,key可以设定在规定时间内自动删除。这里的这个规定时间,就是api在规定时间内不能重复提交。
自定义注解(注解作用于Controller层的API)
@Target(ElementType.METHOD) @Retention(RetentionPolicy.RUNTIME) public @interface NoRepeatSubmission { }
切面逻辑
import com.gotrade.apirepeatrequest.annotation.NoRepeatSubmission; import com.gotrade.apirepeatrequest.common.JacksonSerializer; import com.gotrade.apirepeatrequest.model.Result; import lombok.extern.slf4j.Slf4j; 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.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.ValueOperations; import org.springframework.stereotype.Component; import org.springframework.web.context.request.RequestContextHolder; import org.springframework.web.context.request.ServletRequestAttributes; import javax.servlet.http.HttpServletRequest; import java.nio.charset.StandardCharsets; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.util.Objects; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.TimeUnit; @Slf4j @Aspect @Component public class NoRepeatSubmissionAspect { @Autowired RedisTemplate<String, String> redisTemplate; /** * 环绕通知 * @param pjp * @param ars * @return */ @Around("execution(public * com.gotrade.apirepeatrequest.controller..*.*(..)) && @annotation(ars)") public Object doAround(ProceedingJoinPoint pjp, NoRepeatSubmission ars) { ValueOperations<String, String> opsForValue = redisTemplate.opsForValue(); try { if (ars == null) { return pjp.proceed(); } HttpServletRequest request = ((ServletRequestAttributes) Objects.requireNonNull(RequestContextHolder.getRequestAttributes())).getRequest(); String token = request.getHeader("Token"); if (!checkToken(token)) { return Result.failure("Token无效"); } String servletPath = request.getServletPath(); String jsonString = this.getRequestParasJSONString(pjp); String sha1 = this.generateSHA1(jsonString); // key = token + servlet path String key = token + "-" + servletPath + "-" + sha1; log.info("\n{\n\tServlet Path: {}\n\tToken: {}\n\tJson String: {}\n\tSHA-1: {}\n\tResult Key: {} \n}", servletPath, token, jsonString, sha1, key); // 如果Redis中有这个key, 则url视为重复请求 if (opsForValue.get(key) == null) { Object o = pjp.proceed(); opsForValue.set(key, String.valueOf(0), 3, TimeUnit.SECONDS); return o; } else { return Result.failure("请勿重复请求"); } } catch (Throwable e) { e.printStackTrace(); return Result.failure("验证重复请求时出现未知异常"); } } /** * 获取请求参数 * @param pjp * @return */ private String getRequestParasJSONString(ProceedingJoinPoint pjp) { String[] parameterNames = ((MethodSignature) pjp.getSignature()).getParameterNames(); ConcurrentHashMap<String, String> args = null; if (Objects.nonNull(parameterNames)) { args = new ConcurrentHashMap<>(parameterNames.length); for (int i = 0; i < parameterNames.length; i++) { String value = pjp.getArgs()[i] != null ? pjp.getArgs()[i].toString() : "null"; args.put(parameterNames[i], value); } } return JacksonSerializer.toJSONString(args); } private boolean checkToken(String token) { if (token == null || token.isEmpty()) { return false; } return true; } private String generateSHA1(String str){ if (null == str || 0 == str.length()){ return null; } char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'}; try { MessageDigest mdTemp = MessageDigest.getInstance("SHA1"); mdTemp.update(str.getBytes(StandardCharsets.UTF_8)); byte[] md = mdTemp.digest(); int j = md.length; char[] buf = new char[j * 2]; int k = 0; for (int i = 0; i < j; i++) { byte byte0 = md[i]; buf[k++] = hexDigits[byte0 >>> 4 & 0xf]; buf[k++] = hexDigits[byte0 & 0xf]; } return new String(buf); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } return null; } }
切面主要逻辑代码,就是获取request中相关的信息,然后再拼接成一个key;判断在redis是否存在,不存在就添加并设置规定时间后自动移除,存在就是重复请求 。
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