问题
I have a class named TraceNoGenerator that works like a Sequence in an Oracle Database; I want to use this class to assign a trace number for each request that comes to my web application to log in a log file. When my application received an error, this trace number will display on a web page so that I can easily find the bug using this trace number in the log file.
How can I do this in Log4j?
来源：https://stackoverflow.com/questions/7089241/log-traceno-for-each-request-in-web-application-using-log4j