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:
一、編寫注解類 AccessLimit
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
Interceptor
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
中
Interceptor
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
Controller
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
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