| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.hadoop.lib.servlet; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.slf4j.MDC; |
| |
| 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 java.io.IOException; |
| import java.security.Principal; |
| |
| /** |
| * Filter that sets request contextual information for the slf4j MDC. |
| * <p/> |
| * It sets the following values: |
| * <ul> |
| * <li>hostname: if the {@link HostnameFilter} is present and configured |
| * before this filter</li> |
| * <li>user: the <code>HttpServletRequest.getUserPrincipal().getName()</code></li> |
| * <li>method: the HTTP method fo the request (GET, POST, ...)</li> |
| * <li>path: the path of the request URL</li> |
| * </ul> |
| */ |
| @InterfaceAudience.Private |
| public class MDCFilter implements Filter { |
| |
| /** |
| * Initializes the filter. |
| * <p/> |
| * This implementation is a NOP. |
| * |
| * @param config filter configuration. |
| * |
| * @throws ServletException thrown if the filter could not be initialized. |
| */ |
| @Override |
| public void init(FilterConfig config) throws ServletException { |
| } |
| |
| /** |
| * Sets the slf4j <code>MDC</code> and delegates the request to the chain. |
| * |
| * @param request servlet request. |
| * @param response servlet response. |
| * @param chain filter chain. |
| * |
| * @throws IOException thrown if an IO error occurrs. |
| * @throws ServletException thrown if a servet error occurrs. |
| */ |
| @Override |
| public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) |
| throws IOException, ServletException { |
| try { |
| MDC.clear(); |
| String hostname = HostnameFilter.get(); |
| if (hostname != null) { |
| MDC.put("hostname", HostnameFilter.get()); |
| } |
| Principal principal = ((HttpServletRequest) request).getUserPrincipal(); |
| String user = (principal != null) ? principal.getName() : null; |
| if (user != null) { |
| MDC.put("user", user); |
| } |
| MDC.put("method", ((HttpServletRequest) request).getMethod()); |
| MDC.put("path", ((HttpServletRequest) request).getPathInfo()); |
| chain.doFilter(request, response); |
| } finally { |
| MDC.clear(); |
| } |
| } |
| |
| /** |
| * Destroys the filter. |
| * <p/> |
| * This implementation is a NOP. |
| */ |
| @Override |
| public void destroy() { |
| } |
| } |
| |