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.druid.support.http;
  
  import com.alibaba.druid.stat.DruidStatService;
  import com.alibaba.druid.support.http.util.IPRange;
  import com.alibaba.druid.support.logging.Log;
  import com.alibaba.druid.support.logging.LogFactory;
  import com.alibaba.druid.util.StringUtils;
  
  import javax.servlet.*;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import java.io.IOException;
  
  import static com.alibaba.druid.support.http.ResourceServlet.*;
  
  public class StatViewFilter implements Filter {
      public static final String PARAM_NAME_PATH = "path";
      private static final Log LOG = LogFactory.getLog(StatViewFilter.class);
      private String servletPath = "/druid";
      private String resourcePath = "support/http/resources";
  
      private ResourceHandler handler;
      private DruidStatService statService = DruidStatService.getInstance();
  
      @Override
      public void init(FilterConfig config) throws ServletException {
          if (config == null) {
              return;
          }
  
          String path = config.getInitParameter(PARAM_NAME_PATH);
          if (path != null && !path.isEmpty()) {
              this.servletPath = path;
          }
  
          handler = new ResourceHandler(resourcePath);
  
          String paramUserName = config.getInitParameter(PARAM_NAME_USERNAME);
          if (!StringUtils.isEmpty(paramUserName)) {
              handler.username = paramUserName;
          }
  
          String paramPassword = config.getInitParameter(PARAM_NAME_PASSWORD);
          if (!StringUtils.isEmpty(paramPassword)) {
              handler.password = paramPassword;
          }
  
          String paramRemoteAddressHeader = config.getInitParameter(PARAM_REMOTE_ADDR);
          if (!StringUtils.isEmpty(paramRemoteAddressHeader)) {
              handler.remoteAddressHeader = paramRemoteAddressHeader;
          }
  
          try {
              String param = config.getInitParameter(PARAM_NAME_ALLOW);
              if (param != null && param.trim().length() != 0) {
                  param = param.trim();
                  String[] items = param.split(",");
  
                  for (String item : items) {
                      if (item == null || item.length() == 0) {
                          continue;
                      }
  
                      IPRange ipRange = new IPRange(item);
                      handler.allowList.add(ipRange);
                  }
              }
          } catch (Exception e) {
              String msg = "initParameter config error, allow : " + config.getInitParameter(PARAM_NAME_ALLOW);
              LOG.error(msg, e);
          }
  
          try {
              String param = config.getInitParameter(PARAM_NAME_DENY);
              if (param != null && param.trim().length() != 0) {
                  param = param.trim();
                  String[] items = param.split(",");
  
                  for (String item : items) {
                      if (item == null || item.length() == 0) {
                          continue;
                      }
  
                      IPRange ipRange = new IPRange(item);
                      handler.denyList.add(ipRange);
                  }
              }
          } catch (Exception e) {
              String msg = "initParameter config error, deny : " + config.getInitParameter(PARAM_NAME_DENY);
              LOG.error(msg, e);
          }
      }
  
      @Override
      public void doFilter(ServletRequest request,
                           ServletResponse response,
                           FilterChain chain) throws IOException, ServletException {
          HttpServletRequest httpReq = (HttpServletRequest) request;
          HttpServletResponse httpResp = (HttpServletResponse) response;
          String contextPath = ((HttpServletRequest) request).getContextPath();
  
          String requestURI = httpReq.getRequestURI();
          if (!contextPath.equals("")) {
              requestURI = requestURI.substring(((HttpServletRequest) request).getContextPath().length());
          }
          if (requestURI.equals(servletPath)) {
              httpResp.sendRedirect(httpReq.getRequestURI() + '/');
              return;
          }
  
          handler.service(httpReq, httpResp, servletPath, new ResourceServlet.ProcessCallback() {
              @Override
              public String process(String url) {
                  return statService.service(url);
              }
          });
      }
  
      @Override
      public void destroy() {
      }
  }
  