Spring Cloud Zuul自定義過濾器的實現

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
</dependency>

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.stereotype.Component;

/**
 * 構建zuul自定義過濾器
 */
@Component
public class MyFilter extends ZuulFilter {

  /**
   * 定義過濾器的類型
   * pre:在請求被路由之前執行
   * route:在路由請求的時候執行
   * post:請求路由以後執行
   * error:處理請求時發生錯誤的時候執行
   *
   * @return 過濾器的類型
   */
  @Override
  public String filterType() {
    return "pre";
  }

  /**
   * 過濾器執行的順序，配置多個有順序的過濾
   * 執行順序從小到大
   *
   * @return 執行順序
   */
  @Override
  public int filterOrder() {
    return 1;
  }

  /**
   * 是否開啟過濾器
   * true:開啟
   * false:禁用
   *
   * @return 是否開啟過濾器
   */
  @Override
  public boolean shouldFilter() {
    return true;
  }

  /**
   * 過濾器的業務實現
   *
   * @return null 沒有意義
   * @throws ZuulException 異常信息
   */
  @Override
  public Object run() throws ZuulException {

    System.out.println("per zuul filter...");

    return null;
  }
}

import com.imooc.grace.result.GraceJsonResult;
import com.imooc.grace.result.ResponseStatusEnum;
import com.imooc.utils.IPUtil;
import com.imooc.utils.JsonUtils;
import com.imooc.utils.RedisOperator;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

/**
 * 限制ip頻繁請求
 */
@Component
public class BlackIpFilter extends ZuulFilter {

  /**
   * ip連續請求的次數
   */
  private static final int CONTINUE_COUNTS = 10;
  /**
   * ip判斷的時間間隔，單位秒
   */
  private static final int TIME_INTERVAL = 10;
  /**
   * 限制的時間，單位秒
   */
  private static final int LIMIT_TIMES = 15;

  @Autowired
  private RedisOperator redisOperator;

  @Override
  public String filterType() {
    return "pre";
  }


  @Override
  public int filterOrder() {
    // 這裡設置為2，上面那個過濾器設置為1，則執行順序為 1->2，大傢可以測試一下
    return 2;
  }

  @Override
  public boolean shouldFilter() {
    return true;
  }

  @Override
  public Object run() throws ZuulException {
    // 獲取上下文對象
    RequestContext currentContext = RequestContext.getCurrentContext();
    HttpServletRequest request = currentContext.getRequest();
    // 獲取ip
    String requestIp = IPUtil.getRequestIp(request);

    // 判斷該ip在10秒內請求次數是否超過10次，超過則限制該ip15秒內不能訪問，15秒後再放行
    final String ipRedisKey = "zuul-ip:" + requestIp;
    final String ipRedisLimitKey = "zuul-ip-limit:" + requestIp;

    // 獲取當前ip這個key的剩餘時間
    long limitLeftTime = redisOperator.ttl(ipRedisLimitKey);
    // 判斷該ip是否還有剩餘時間
    if (limitLeftTime > 0) {
      stopRequest(currentContext);
      return null;
    }

    // 在redis中累加ip的請求次數
    long requestCounts = redisOperator.increment(ipRedisKey, 1);
    if (requestCounts == 1) {
      redisOperator.expire(ipRedisKey, TIME_INTERVAL);
    }

    if (requestCounts > CONTINUE_COUNTS) {
      // 限制ip訪問
      redisOperator.set(ipRedisLimitKey, ipRedisLimitKey, LIMIT_TIMES);
      stopRequest(currentContext);
    }

    return null;
  }

  private void stopRequest(RequestContext context) {
    // 停止zuul繼續向下路由，禁止請求通信
    context.setSendZuulResponse(false);
    // 返回響應碼200
    context.setResponseStatusCode(200);

    // TODO 要返回提示的json內容（可以自定義任何響應內容）
    // 例如 {"status":544,"msg":"請求過於頻繁，請稍後再試","success":false,"data":null}
    String result = "json內容";

    // 設置返回內容
    context.setResponseBody(result);
    // 設置編碼
    context.getResponse().setCharacterEncoding("utf-8");
    // 設置返回內容格式為json
    context.getResponse().setContentType(MediaType.APPLICATION_JSON_VALUE);
  }
}

import javax.servlet.http.HttpServletRequest;

/**
 * 獲取ip工具類
 */
public class IPUtil {

  /**
   * 獲取請求IP:
   * 用戶的真實IP不能使用request.getRemoteAddr()
   * 這是因為可能會使用一些代理軟件，這樣ip獲取就不準確瞭
   * 此外我們如果使用瞭多級（LVS/Nginx）反向代理的話，ip需要從X-Forwarded-For中獲得第一個非unknown的IP才是用戶的有效ip。
   */
  public static String getRequestIp(HttpServletRequest request) {
    String ip = request.getHeader("x-forwarded-for");
    if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("Proxy-Client-IP");
    }
    if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("WL-Proxy-Client-IP");
    }
    if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("HTTP_CLIENT_IP");
    }
    if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("HTTP_X_FORWARDED_FOR");
    }
    if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getRemoteAddr();
    }
    return ip;
  }
}