content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alibaba.csp.sentinel.adapter.gateway.zuul2.filters.outbound;
  
  import java.util.Deque;
  
  import com.alibaba.csp.sentinel.Tracer;
  import com.alibaba.csp.sentinel.adapter.gateway.zuul2.constants.SentinelZuul2Constants;
  import com.alibaba.csp.sentinel.adapter.gateway.zuul2.filters.EntryHolder;
  import com.alibaba.csp.sentinel.slots.block.BlockException;
  import com.netflix.zuul.context.SessionContext;
  import com.netflix.zuul.filters.http.HttpOutboundFilter;
  import com.netflix.zuul.message.http.HttpResponseMessage;
  import rx.Observable;
  
  /**
   * The Zuul outbound filter which will complete the Sentinel entries and
   * trace the exception that happened in previous filters.
   *
   * @author wavesZh
   */
  public class SentinelZuulOutboundFilter extends HttpOutboundFilter {
  
      private final int order;
  
      public SentinelZuulOutboundFilter(int order) {
          this.order = order;
      }
  
      @Override
      public int filterOrder() {
          return order;
      }
  
      @Override
      public Observable<HttpResponseMessage> applyAsync(HttpResponseMessage input) {
          return Observable.just(apply(input));
      }
  
      public HttpResponseMessage apply(HttpResponseMessage response) {
          SessionContext context = response.getContext();
  
          if (context.get(SentinelZuul2Constants.ZUUL_CTX_SENTINEL_ENTRIES_KEY) == null) {
              return response;
          }
          boolean previousBlocked = context.getFilterErrors().stream()
              .anyMatch(e -> BlockException.isBlockException(e.getException()));
          Deque<EntryHolder> holders = (Deque<EntryHolder>) context.get(SentinelZuul2Constants.ZUUL_CTX_SENTINEL_ENTRIES_KEY);
          while (!holders.isEmpty()) {
              EntryHolder holder = holders.pop();
              if (!previousBlocked) {
                  Tracer.traceEntry(context.getError(), holder.getEntry());
                  holder.getEntry().exit(1, holder.getParams());
              }
          }
          return response;
      }
  
  
      @Override
      public boolean shouldFilter(HttpResponseMessage msg) {
          return true;
      }
  }
  