天天看點

基于注解實作 SpringBoot 接口防刷

文章目錄

    • 一、編寫注解類 `AccessLimit`
    • 二、在`Interceptor`攔截器中實作攔截邏輯
    • 三、把`Interceptor`注冊到`springboot`中
    • 四、在`Controller`中加入注解實作接口防刷
    • 五、測試通路
    • 附:StatusCode.java、Result.java、application.yml

該示例項目通過自定義注解,實作接口通路次數控制,進而實作接口防刷功能,項目結構如下:

基于注解實作 SpringBoot 接口防刷

一、編寫注解類

AccessLimit

package cn.mygweb.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 通路控制注解(實作接口防刷功能)
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface AccessLimit {
    /**
     * 限制周期(機關為秒)
     *
     * @return
     */
    int seconds();

    /**
     * 規定周期内限制次數
     *
     * @return
     */
    int maxCount();

    /**
     * 是否需要登入
     *
     * @return
     */
    boolean needLogin() default false;
}
           

二、在

Interceptor

攔截器中實作攔截邏輯

package cn.mygweb.interceptor;

import cn.mygweb.annotation.AccessLimit;
import cn.mygweb.entity.Result;
import cn.mygweb.entity.StatusCode;
import com.alibaba.fastjson.JSON;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;

/**
 * 通路控制攔截器
 */
@Component
public class AccessLimitInterceptor extends HandlerInterceptorAdapter {

    //模拟資料存儲,實際業務中可以自定義實作方式
    private static Map<String, AccessInfo> accessInfoMap = new HashMap<>();

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
                             Object handler) throws Exception {
        //判斷請求是否屬于方法的請求
        if (handler instanceof HandlerMethod) {
            HandlerMethod hm = (HandlerMethod) handler;

            //擷取方法中的注解,看是否有該注解
            AccessLimit accessLimit = hm.getMethodAnnotation(AccessLimit.class);
            if (accessLimit == null) {
                return true;
            }
            int seconds = accessLimit.seconds();
            int maxCount = accessLimit.maxCount();
            boolean needLogin = accessLimit.needLogin();
            String key = request.getRequestURI();
            //如果需要登入
            if (needLogin) {
                //擷取登入的session進行判斷
                //……
                key += " " + "userA";//這裡假設使用者是userA,實際項目中可以改為userId
            }

            //模拟從redis中擷取資料
            AccessInfo accessInfo = accessInfoMap.get(key);
            if (accessInfo == null) {
                //第一次通路
                accessInfo = new AccessInfo();
                accessInfo.setFirstVisitTimestamp(System.currentTimeMillis());
                accessInfo.setAccessCount(1);
                accessInfoMap.put(key, accessInfo);
            } else if (accessInfo.getAccessCount() < maxCount) {
                //通路次數加1
                accessInfo.setAccessCount(accessInfo.getAccessCount() + 1);
                accessInfoMap.put(key, accessInfo);
            } else {
                //超出通路次數,判斷時間是否超出設定時間
                if ((System.currentTimeMillis() - accessInfo.getFirstVisitTimestamp()) <= seconds * 1000) {
                    //如果還在設定時間内,則為不合法請求,傳回錯誤資訊
                    render(response, "達到通路限制次數,請稍後重試!");
                    return false;
                } else {
                    //如果超出設定時間,則為合理的請求,将之前的請求清空,重新計數
                    accessInfo.setFirstVisitTimestamp(System.currentTimeMillis());
                    accessInfo.setAccessCount(1);
                    accessInfoMap.put(key, accessInfo);
                }
            }
        }
        return true;
    }

    /**
     * 向頁面發送消息
     *
     * @param response
     * @param msg
     * @throws Exception
     */
    private void render(HttpServletResponse response, String msg) throws Exception {
        response.setContentType("application/json;charset=UTF-8");
        OutputStream out = response.getOutputStream();
        String str = JSON.toJSONString(new Result(true, StatusCode.ACCESSERROR, msg));
        out.write(str.getBytes("UTF-8"));
        out.flush();
        out.close();
    }

    /**
     * 封裝的通路資訊對象
     */
    class AccessInfo {

        /**
         * 一個計數周期内第一次通路的時間戳
         */
        private long firstVisitTimestamp;
        /**
         * 通路次數統計
         */
        private int accessCount;

        public long getFirstVisitTimestamp() {
            return firstVisitTimestamp;
        }

        public void setFirstVisitTimestamp(long firstVisitTimestamp) {
            this.firstVisitTimestamp = firstVisitTimestamp;
        }

        public int getAccessCount() {
            return accessCount;
        }

        public void setAccessCount(int accessCount) {
            this.accessCount = accessCount;
        }

        @Override
        public String toString() {
            return "AccessInfo{" +
                    "firstVisitTimestamp=" + firstVisitTimestamp +
                    ", accessCount=" + accessCount +
                    '}';
        }
    }
}
           

三、把

Interceptor

注冊到

springboot

package cn.mygweb.config;

import cn.mygweb.interceptor.AccessLimitInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * 攔截器注冊配置
 */
@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //注冊攔截器
        registry.addInterceptor(new AccessLimitInterceptor());
    }
}
           

四、在

Controller

中加入注解實作接口防刷

package cn.mygweb.controller;

import cn.mygweb.annotation.AccessLimit;
import cn.mygweb.entity.Result;
import cn.mygweb.entity.StatusCode;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/access")
public class AccessController {

    @AccessLimit(seconds = 5, maxCount = 2)//通路控制,5秒内隻能通路2次
    @GetMapping
    public Result access() {
        return new Result(true, StatusCode.OK, "通路成功!");
    }

}
           

五、測試通路

基于注解實作 SpringBoot 接口防刷

附:StatusCode.java、Result.java、application.yml

StatusCode類

package cn.mygweb.entity;

/**
 * 傳回狀态碼
 */
public class StatusCode {
    public static final int OK = 20000;//成功
    public static final int ERROR = 20001;//失敗
    public static final int LOGINERROR = 20002;//使用者名或密碼錯誤
    public static final int ACCESSERROR = 20003;//權限不足
    public static final int REMOTEERROR = 20004;//遠端調用失敗
    public static final int REPERROR = 20005;//重複操作
    public static final int NOTFOUNDERROR = 20006;//沒有對應的搶購資料
}
           

Result類:

package cn.mygweb.entity;

import java.io.Serializable;

/**
 * 響應結果
 */
public class Result<T> implements Serializable {
    private boolean flag;//是否成功
    private Integer code;//傳回碼
    private String message;//傳回消息
    private T data;//傳回資料

    public Result(boolean flag, Integer code, String message, Object data) {
        this.flag = flag;
        this.code = code;
        this.message = message;
        this.data = (T) data;
    }

    public Result(boolean flag, Integer code, String message) {
        this.flag = flag;
        this.code = code;
        this.message = message;
    }

    public Result() {
        this.flag = true;
        this.code = StatusCode.OK;
        this.message = "操作成功!";
    }

    public boolean isFlag() {
        return flag;
    }

    public void setFlag(boolean flag) {
        this.flag = flag;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }
}
           

applications.yml:

server:
  port: 8080