1 /* 2 * Copyright 2010 University Corporation for Advanced Internet Development, Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package edu.internet2.middleware.shibboleth.common.log; 18 19 import java.io.IOException; 20 21 import javax.servlet.Filter; 22 import javax.servlet.FilterChain; 23 import javax.servlet.FilterConfig; 24 import javax.servlet.ServletException; 25 import javax.servlet.ServletRequest; 26 import javax.servlet.ServletResponse; 27 28 import org.slf4j.MDC; 29 30 /** 31 * A Servlet filter which clears all the MDC state that has been accumulated during the processing of a request. It 32 * should be installed as near as possible to the beginning of the effective filter chain - and in particular prior to 33 * any filters which make use of MDC in their own logging - so that this filter will be last when the request stack 34 * unwinds. 35 */ 36 public class SLF4JMDCCleanupFilter implements Filter { 37 38 /** {@inheritDoc} */ 39 public void destroy() { 40 } 41 42 /** {@inheritDoc} */ 43 public void init(FilterConfig filterConfig) throws ServletException { 44 } 45 46 /** {@inheritDoc} */ 47 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, 48 ServletException { 49 50 try { 51 chain.doFilter(request, response); 52 } finally { 53 MDC.clear(); 54 } 55 56 } 57 58 }