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.servlet;
  
  import java.io.IOException;
  
  import javax.servlet.Filter;
  import javax.servlet.FilterChain;
  import javax.servlet.FilterConfig;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import com.alibaba.csp.sentinel.Entry;
  import com.alibaba.csp.sentinel.ResourceTypeConstants;
  import com.alibaba.csp.sentinel.SphU;
  import com.alibaba.csp.sentinel.Tracer;
  import com.alibaba.csp.sentinel.adapter.servlet.callback.WebCallbackManager;
  import com.alibaba.csp.sentinel.adapter.servlet.config.WebServletConfig;
  import com.alibaba.csp.sentinel.context.ContextUtil;
  import com.alibaba.csp.sentinel.slots.block.BlockException;
  
  /***
   * Servlet filter for all requests.
   *
   * @author youji.zj
   */
  public class CommonTotalFilter implements Filter {
  
      public static final String TOTAL_URL_REQUEST = "total-url-request";
  
      @Override
      public void init(FilterConfig filterConfig) {
  
      }
  
      @Override
      public void doFilter(ServletRequest request, ServletResponse response,
                           FilterChain chain) throws IOException, ServletException {
          HttpServletRequest sRequest = (HttpServletRequest)request;
  
          Entry entry = null;
          try {
              ContextUtil.enter(WebServletConfig.WEB_SERVLET_CONTEXT_NAME);
              entry = SphU.entry(TOTAL_URL_REQUEST, ResourceTypeConstants.COMMON_WEB);
              chain.doFilter(request, response);
          } catch (BlockException e) {
              HttpServletResponse sResponse = (HttpServletResponse)response;
              WebCallbackManager.getUrlBlockHandler().blocked(sRequest, sResponse, e);
          } catch (IOException | ServletException | RuntimeException e2) {
              Tracer.trace(e2);
              throw e2;
          } finally {
              if (entry != null) {
                  entry.exit();
              }
              ContextUtil.exit();
          }
      }
  
      @Override
      public void destroy() {
  
      }
  
  }
  