Java后臺(tái)防止客戶端重復(fù)請(qǐng)求、提交表單實(shí)現(xiàn)原理

/**
 * @Title: SameUrlData
 * @Description: 自定義注解防止表單重復(fù)提交
 * @Auther: xhq
 * @Version: 1.0
 * @create 2019/3/26 10:43
 */
@Inherited
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SameUrlData {

}

import com.alibaba.fastjson.JSONObject;
import com.tuohang.hydra.framework.common.spring.SpringKit;
import com.tuohang.hydra.toolkit.basis.string.StringKit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.redis.core.StringRedisTemplate;
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.lang.reflect.Method;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.TimeUnit;

/**
 * @Title: 防止用戶重復(fù)提交數(shù)據(jù)攔截器
 * @Description: 將用戶訪問(wèn)的url和參數(shù)結(jié)合token存入redis，每次訪問(wèn)進(jìn)行驗(yàn)證是否重復(fù)請(qǐng)求接口
 * @Auther: xhq
 * @Version: 1.0
 * @create 2019/3/26 10:35
 */
@Component
public class SameUrlDataInterceptor extends HandlerInterceptorAdapter {

  private static Logger LOG = LoggerFactory.getLogger(SameUrlDataInterceptor.class);

  /**
   * 是否阻止提交,fasle阻止,true放行
   * @return
   */
  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    if (handler instanceof HandlerMethod) {
      HandlerMethod handlerMethod = (HandlerMethod) handler;
      Method method = handlerMethod.getMethod();
      SameUrlData annotation = method.getAnnotation(SameUrlData.class);
      if (annotation != null) {
        if(repeatDataValidator(request)){
          //請(qǐng)求數(shù)據(jù)相同
          LOG.warn("please don't repeat submit,url:"+ request.getServletPath());
          JSONObject result = new JSONObject();
          result.put("statusCode","500");
          result.put("message","請(qǐng)勿重復(fù)請(qǐng)求");
          response.setCharacterEncoding("UTF-8");
          response.setContentType("application/json; charset=utf-8");
          response.getWriter().write(result.toString());
          response.getWriter().close();
//          攔截之后跳轉(zhuǎn)頁(yè)面
//          String formRequest = request.getRequestURI();
//          request.setAttribute("myurl", formRequest);
//          request.getRequestDispatcher("/WebRoot/common/error/jsp/error_message.jsp").forward(request, response);
          return false;
        }else {//如果不是重復(fù)相同數(shù)據(jù)
          return true;
        }
      }
      return true;
    } else {
      return super.preHandle(request, response, handler);
    }
  }
  /**
   * 驗(yàn)證同一個(gè)url數(shù)據(jù)是否相同提交,相同返回true
   * @param httpServletRequest
   * @return
   */
  public boolean repeatDataValidator(HttpServletRequest httpServletRequest){
    //獲取請(qǐng)求參數(shù)map
    Map<String, String[]> parameterMap = httpServletRequest.getParameterMap();
    Iterator<Map.Entry<String, String[]>> it = parameterMap.entrySet().iterator();
    String token = "";
    Map<String, String[]> parameterMapNew = new HashMap<>();
    while(it.hasNext()){
      Map.Entry<String, String[]> entry = it.next();
      if(!entry.getKey().equals("timeStamp") && !entry.getKey().equals("sign")){
        //去除sign和timeStamp這兩個(gè)參數(shù)，因?yàn)檫@兩個(gè)參數(shù)一直在變化
        parameterMapNew.put(entry.getKey(), entry.getValue());
        if(entry.getKey().equals("token")) {
          token = entry.getValue()[0];
        }
      }
    }
    if (StringKit.isBlank(token)){
      //如果沒(méi)有token，直接放行
      return false;
    }
    //過(guò)濾過(guò)后的請(qǐng)求內(nèi)容
    String params = JSONObject.toJSONString(parameterMapNew);

    System.out.println("params==========="+params);

    String url = httpServletRequest.getRequestURI();
    Map<String,String> map = new HashMap<>();
    //key為接口，value為參數(shù)
    map.put(url, params);
    String nowUrlParams = map.toString();

    StringRedisTemplate smsRedisTemplate = SpringKit.getBean(StringRedisTemplate.class);
    String redisKey = token + url;
    String preUrlParams = smsRedisTemplate.opsForValue().get(redisKey);
    if(preUrlParams == null){
      //如果上一個(gè)數(shù)據(jù)為null,表示還沒(méi)有訪問(wèn)頁(yè)面
      //存放并且設(shè)置有效期，2秒
      smsRedisTemplate.opsForValue().set(redisKey, nowUrlParams, 2, TimeUnit.SECONDS);
      return false;
    }else{//否則，已經(jīng)訪問(wèn)過(guò)頁(yè)面
      if(preUrlParams.equals(nowUrlParams)){
        //如果上次url+數(shù)據(jù)和本次url+數(shù)據(jù)相同，則表示重復(fù)添加數(shù)據(jù)
        return true;
      }else{//如果上次 url+數(shù)據(jù) 和本次url加數(shù)據(jù)不同，則不是重復(fù)提交
        smsRedisTemplate.opsForValue().set(redisKey, nowUrlParams, 1, TimeUnit.SECONDS);
        return false;
      }
    }
  }
}

@Configuration
public class WebMvcConfigExt extends WebMvcConfig {

  /**
   * 防止重復(fù)提交攔截器
   */
  @Autowired
  private SameUrlDataInterceptor sameUrlDataInterceptor;

  @Override
  public void addInterceptors(InterceptorRegistry registry) {
    // 避開(kāi)靜態(tài)資源
    List<String> resourcePaths = defineResourcePaths();
    registry.addInterceptor(sameUrlDataInterceptor).addPathPatterns("/**").excludePathPatterns(resourcePaths);// 重復(fù)請(qǐng)求
  }

  /**
   * 自定義靜態(tài)資源路徑
   * 
   * @return
   */
  @Override
  public List<String> defineResourcePaths() {
    List<String> patterns = new ArrayList<>();
    patterns.add("/assets/**");
    patterns.add("/upload/**");
    patterns.add("/static/**");
    patterns.add("/common/**");
    patterns.add("/error");
    return patterns;
  }
}

@SameUrlData
@ResponseBody
@RequestMapping(value = "/saveOrUpdate")
public String saveOrUpdate(){
}