Log4J Custom Fields
java, log4j
Solution
From the example you posted, I can only guess that `AppServerPatternLayout` is not in the package `logging`. Everything else looks find. Add
log4j.DEBUG=true
to your properties file. log4j will then dump what it does while reading the properties. Maybe that gives you an idea what's wrong.
If that doesn't help, consider to use Nested Diagnostic Contexts.
Problem
Introduction: I'm trying to get additional fields to log with log4j, and its working but only when I create an appender in code and not in the log4j.properties Progress: - Used this article Adding Conversion Characters to PatternLayout for log4j 1.1.3 - Made a sample app for log4j 1.2 Problem: using the properties file it will run but won't use AppServerPatternLayout so the custom fields aren't displayed. Download Code customlog.properties ``` log4j.rootLogger=FATAL log4j.logger.some.log=INFO,stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=logging.AppServerPatternLayout log4j.appender.stdout.layout.ConversionPattern=-----------------using log file------------------------%nTime: %d%nHost: %h%nServer: %s%nComponent: %b%nVersion: %v%nPriority: %p%nThread Id: %t%nContext: %x%nMessage: %m%n ``` Main.java logging without a log4j properties file ``` AppServerLoggerFactory factory; factory = new AppServerLoggerFactory("MyServer", "MyComponent", "1.0"); AppServerLogger.setFactory(factory); Logger logger = AppServerLogger.getLogger("some.log"); PatternLayout layout = new AppServerPatternLayout( formatString ); logger.addAppender( new ConsoleAppender(layout) ); logger.info("Hello"); ``` Main.java logging with a log4j properties file ``` PropertyConfigurator.configure("customlog.properties"); AppServerLoggerFactory factory; factory = new AppServerLoggerFactory("MyServer", "MyComponent", "1.0"); AppServerLogger.setFactory(factory); Logger logger = AppServerLogger.getLogger("some.log"); logger.info("Hello"); ``` Expected output ``` ----------------using in code appender---------------------- Time: 2009-11-06 12:55:05,785 Host: M1330 Server: MyServer Component: MyComponent Version: 1.0 Priority: INFO Thread Id: main Context: Message: logging config from code ``` Actual output ``` -----------------using log file------------------------ Time: 2009-11-06 12:56:17,983 Host: Server: Component: Version: Priority: INFO Thread Id: main Context: Message: logging config from customlog.properties ``` Solution Using MDC you can add custom fields like ``` MDC.put("Version", versionName); Logger log = LogManager.getLogger("some.log"); log.info("Hello"); ``` and pull it out in the log4j.properties with a UPPER case X ``` log4j.appender.stdout.layout.ConversionPattern=%X{Version} ```