demo.SessionMDCFilter.java Source code

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Here is the source code for demo.SessionMDCFilter.java

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/*
 * Copyright 2002-2015 the original author or authors.
 *
 * 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 demo;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.slf4j.MDC;
import org.springframework.core.annotation.Order;
import org.springframework.session.web.http.SessionRepositoryFilter;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;

/**
 * @author Rob Winch
 *
 */
@Order(SessionRepositoryFilter.DEFAULT_ORDER + 5)
@Component
public class SessionMDCFilter extends OncePerRequestFilter {
    private static final String MDC_KEY = "spring.log.configuration";

    /* (non-Javadoc)
     * @see org.springframework.web.filter.OncePerRequestFilter#doFilterInternal(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, javax.servlet.FilterChain)
     */
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws ServletException, IOException {
        try {
            configureMDC(request);
            chain.doFilter(request, response);
        } finally {
            MDC.remove(MDC_KEY);
        }
    }

    private void configureMDC(HttpServletRequest request) {
        HttpSession session = request.getSession(false);
        if (session == null) {
            return;
        }
        String config = (String) session.getAttribute(MDC_KEY);
        if (config == null) {
            return;
        }
        MDC.put(MDC_KEY, config);
    }

}