1 /* 2 * Licensed to the University Corporation for Advanced Internet Development, 3 * Inc. (UCAID) under one or more contributor license agreements. See the 4 * NOTICE file distributed with this work for additional information regarding 5 * copyright ownership. The UCAID licenses this file to You under the Apache 6 * License, Version 2.0 (the "License"); you may not use this file except in 7 * compliance with the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package edu.internet2.middleware.shibboleth.common.log; 19 20 import java.io.IOException; 21 22 import javax.servlet.Filter; 23 import javax.servlet.FilterChain; 24 import javax.servlet.FilterConfig; 25 import javax.servlet.ServletException; 26 import javax.servlet.ServletRequest; 27 import javax.servlet.ServletResponse; 28 29 import org.slf4j.MDC; 30 31 /** 32 * A Servlet filter which clears all the MDC state that has been accumulated during the processing of a request. It 33 * should be installed as near as possible to the beginning of the effective filter chain - and in particular prior to 34 * any filters which make use of MDC in their own logging - so that this filter will be last when the request stack 35 * unwinds. 36 */ 37 public class SLF4JMDCCleanupFilter implements Filter { 38 39 /** {@inheritDoc} */ 40 public void destroy() { 41 } 42 43 /** {@inheritDoc} */ 44 public void init(FilterConfig filterConfig) throws ServletException { 45 } 46 47 /** {@inheritDoc} */ 48 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, 49 ServletException { 50 51 try { 52 chain.doFilter(request, response); 53 } finally { 54 MDC.clear(); 55 } 56 57 } 58 59 }