ELK+MDC追踪日志 ---- Spring的Filter实现

Maven依赖

<dependency>
   <groupId>org.slf4j</groupId>
   <artifactId>slf4j-log4j12</artifactId>
   <version>1.7.25</version>
</dependency>

log4j.properties

只用看%X{uuid}那里

log4j.logger.com.ibatis=debug
log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=debug
log4j.logger.com.ibatis.common.jdbc.ScriptRunner=debug
log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=debug
log4j.logger.java.sql.Connection=debug
log4j.logger.java.sql.Statement=debug
log4j.logger.java.sql.PreparedStatement=debug

log4j.rootLogger = INFO,fileout,console
log4j.logger.crmLogger=DEBUG,fileout,console

log4j.appender.fileout=org.apache.log4j.DailyRollingFileAppender
log4j.appender.fileout.Threshold=DEBUG 
log4j.appender.fileout.File=${log4jUrl}

log4j.appender.fileout.Append=true
log4j.appender.fileout.DatePattern='.'yyyyMMdd
log4j.appender.fileout.layout=org.apache.log4j.PatternLayout 
log4j.appender.fileout.layout.ConversionPattern=[%d{yyyy-MM-dd HH:mm:ss.SSS}] [%5p] [uuid=%X{uuid}] [%t] [%class.%M] %m%n

log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=[%d{yyyy-MM-dd HH:mm:ss.SSS}] [%5p] [uuid=%X{uuid}] [%t] [%class.%M] %m%n
log4j.appender.console.Threshold=DEBUG 
log4j.appender.file.encoding=UTF-8


log4j.logger.org.springframework=error,fileout
log4j.logger.org.apache.commons=error,fileout
log4j.logger.net.sf.ehcache=error,fileout
log4j.logger.org.apache.ibatis=error,fileout
log4j.logger.org.mybatis.spring=error,fileout
log4j.logger.com.fuiou= debug,fileout

实现Filter

• 1、实现一个Filter，使用MDC.put(key, val)写入需要打印的参数。

import org.slf4j.MDC;

public class MDCFilter implements Filter {

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws IOException,ServletException {        
        try {
            MDC.put("requestMethod", request.getMethod().toUpperCase());
            MDC.put("requestUri", request.getRequestURI());
            MDC.put("uuid", UUID.randomUUID().toString().replace("-", ""));
            MDC.put("ip", request.getRemoteAddr());
            User requestUser = (User) request.getAttribute(Constants.REQUEST_USER);
            if (requestUser != null) {
                MDC.put("uid", String.valueOf(requestUser.getId()));
            }
        } catch (Exception e) {
            logger.error("init MDC error.", e);
        }
        try {
            filterChain.doFilter(request, response);
        } finally {
            MDC.clear();
        }
    }
}

• 2、也可以在项目中现有的Filter中doFillter中加上一行，但记得要在最后finally中MDC.clear();
  如果web.xml有多个拦截器，可以选择在最后一个Filter的finally调用MDC.clear();

 public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        try {
         	MDC.put("uuid", UUID.randomUUID().toString().replaceAll("-", ""));
         	// ......此处省略其他处理步骤
            // 继续过滤
        	chain.doFilter(req, res);
        } finally {
            MDC.clear();
        }         	
 }