content: /*
   * Copyright 1999-2020 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.apache.httpclient;
  
  import com.alibaba.csp.sentinel.*;
  import com.alibaba.csp.sentinel.adapter.apache.httpclient.config.SentinelApacheHttpClientConfig;
  import com.alibaba.csp.sentinel.slots.block.BlockException;
  import com.alibaba.csp.sentinel.util.StringUtil;
  import org.apache.http.HttpException;
  import org.apache.http.client.methods.CloseableHttpResponse;
  import org.apache.http.client.methods.HttpExecutionAware;
  import org.apache.http.client.methods.HttpRequestWrapper;
  import org.apache.http.client.protocol.HttpClientContext;
  import org.apache.http.conn.routing.HttpRoute;
  import org.apache.http.impl.client.HttpClientBuilder;
  import org.apache.http.impl.execchain.ClientExecChain;
  
  import java.io.IOException;
  
  /**
   * @author zhaoyuguang
   */
  public class SentinelApacheHttpClientBuilder extends HttpClientBuilder {
  
      private final SentinelApacheHttpClientConfig config;
  
      public SentinelApacheHttpClientBuilder(){
          this.config = new SentinelApacheHttpClientConfig();
      }
  
      public SentinelApacheHttpClientBuilder(SentinelApacheHttpClientConfig config){
          this.config = config;
      }
  
      @Override
      protected ClientExecChain decorateMainExec(final ClientExecChain mainExec) {
          return new ClientExecChain() {
              @Override
              public CloseableHttpResponse execute(HttpRoute route, HttpRequestWrapper request,
                                                   HttpClientContext clientContext, HttpExecutionAware execAware)
                      throws IOException, HttpException {
                  Entry entry = null;
                  try {
                      String name = config.getExtractor().extractor(request);
                      if (!StringUtil.isEmpty(config.getPrefix())) {
                          name = config.getPrefix() + name;
                      }
                      entry = SphU.entry(name, ResourceTypeConstants.COMMON_WEB, EntryType.OUT);
                      return mainExec.execute(route, request, clientContext, execAware);
                  } catch (BlockException e) {
                      return config.getFallback().handle(request, e);
                  } catch (Throwable t) {
                      Tracer.traceEntry(t, entry);
                      throw t;
                  } finally {
                      if (entry != null) {
                          entry.exit();
                      }
                  }
              }
          };
      }
  }
  