java中aop实现接口访问频率限制

package com.yang.prevent;
 
import java.lang.annotation.*;
 

@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Prevent {
 
    
    long value() default 60;

    
    long times() default 1;
 
    
    String message() default "";
 
    
    PreventStrategy strategy() default PreventStrategy.DEFAULT;
}

package com.yang.prevent;


public enum PreventStrategy {

    
    DEFAULT
}

package com.yang.prevent;

import com.yang.common.StatusCode;
import com.yang.constant.redis.RedisKey;
import com.yang.exception.BusinessException;
import com.yang.utils.IpUtils;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import java.lang.reflect.Method;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.Objects;
import java.util.concurrent.TimeUnit;


@Aspect
@Component
public class PreventAop {

    @Resource
    private RedisTemplate<String, Long> redisTemplate;


    
    @Pointcut("@annotation(com.yang.prevent.Prevent)")
    public void pointcut() {}


    
    @Before("pointcut()")
    public void joinPoint(JoinPoint joinPoint) throws Exception {
        // 获取调用者ip
        RequestAttributes requestAttributes = RequestContextHolder.currentRequestAttributes();
        HttpServletRequest httpServletRequest = ((ServletRequestAttributes) requestAttributes).getRequest();
        String userIP = IpUtils.getUserIP(httpServletRequest);
        // 获取调用接口方法名
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        Method method = joinPoint.getTarget().getClass().getMethod(
                methodSignature.getName(),
                methodSignature.getParameterTypes()); // 获取该接口方法
        String methodFullName = method.getDeclaringClass().getName() + method.getName(); // 获取到方法名
        Prevent preventAnnotation = method.getAnnotation(Prevent.class); // 获取该接口上的prevent注解（为了使用该注解内的参数）
        // 执行对应策略
        entrance(preventAnnotation, userIP, methodFullName);
    }


    
    private void entrance(Prevent prevent, String userIP, String methodFullName) throws Exception {
        PreventStrategy strategy = prevent.strategy(); // 获取校验策略
        if (Objects.requireNonNull(strategy) == PreventStrategy.DEFAULT) { // 默认就是default策略，执行default策略方法
            defaultHandle(userIP, prevent, methodFullName);
        } else {
            throw new BusinessException(StatusCode.FORBIDDEN, "无效的策略");
        }
    }


    
    private void defaultHandle(String userIP, Prevent prevent, String methodFullName) throws Exception {
        String base64StrIP = toBase64String(userIP); // 加密用户ip（避免ip存在一些特殊字符作为redis的key不合法）
        long expire = prevent.value(); // 获取访问限制时间
        long times = prevent.times(); // 获取访问限制次数
        // 限制特定时间内访问特定次数
        long count = redisTemplate.opsForValue().increment(
                RedisKey.PREVENT_METHOD_NAME + base64StrIP + ":" + methodFullName, 1); // 访问次数+1
        if (count == 1) { // 如果访问次数为1，则重置访问限制时间（即redis超时时间）
            redisTemplate.expire(
                    RedisKey.PREVENT_METHOD_NAME + base64StrIP + ":" + methodFullName,
                    expire,
                    TimeUnit.SECONDS);
        }
        if (count > times) { // 如果访问次数超出访问限制次数，则禁止访问
            // 如果有限制信息则使用限制信息，没有则使用默认限制信息
            String errorMessage =
                    !StringUtils.isEmpty(prevent.message()) ? prevent.message() : expire + "秒内不允许重复请求";
            throw new BusinessException(StatusCode.FORBIDDEN, errorMessage);
        }
    }


    
    private String toBase64String(String obj) throws Exception {
        if (StringUtils.isEmpty(obj)) {
            return null;
        }
        Base64.Encoder encoder = Base64.getEncoder();
        byte[] bytes = obj.getBytes(StandardCharsets.UTF_8);
        return encoder.encodeToString(bytes);
    }
}