Question

I’m trying to programmatically configure LogBack’s RollingFileAppender (ch.qos.logback.core.rolling.RollingFileAppender) and it doesn’t seem to be working. When I’m using FileAppender, everything seems to be working fine with exact same configuration (less policies/trigger) so I’m guessing it’s not a permission issue. I tried commenting out all policy configuration and that didn’t help either. Below is my sample code, with some hard-coded values. Also, there’s no error at all what so ever. When I debug the LogBack source code, I didn’t see anything that could have gone wrong.

Any hint is appreciative. I need to get this working without a configuration file since that’s a restriction in my organization. I’m testing this out on a MacBook.

Logger logger = (Logger)LoggerFactory.getLogger(applicationName); 
LoggerContext lc = (LoggerContext) LoggerFactory.getILoggerFactory(); 
lc.reset(); 

RollingFileAppender<ILoggingEvent> fileAppender = 
    new RollingFileAppender<ILoggingEvent>(); 
fileAppender.setAppend(true); 
fileAppender.setFile("/Users/Jack/Desktop/logs/" + applicationName + ".log"); 
fileAppender.setContext(lc); 

SizeBasedTriggeringPolicy<ILoggingEvent> rPolicy = 
    new SizeBasedTriggeringPolicy<ILoggingEvent>("20MB"); 
fileAppender.setTriggeringPolicy(rPolicy); 
TimeBasedRollingPolicy<ILoggingEvent> tPolicy = 
    new TimeBasedRollingPolicy<ILoggingEvent>(); 
tPolicy.setFileNamePattern("/archive/" + applicationName + ".%d"); 
tPolicy.setMaxHistory(180); 
tPolicy.setParent(fileAppender); 
tPolicy.setContext(lc); 

PatternLayout pl = new PatternLayout(); 
pl.setPattern("%d %5p %t [%c:%L] %m%n)"); 
pl.setContext(lc); 
pl.start(); 

fileAppender.setLayout(pl); 
fileAppender.start(); 

logger.addAppender(fileAppender); 
logger.setLevel(Level.DEBUG); 

logger.debug("Test message");

Answer 1

The key issues are as follow:

• RollingFileAppender must have RollingPolicy
• RollingFileAppender requires PatternLayoutEncoder instead of PatternEncoder
• RollingPolicy must also be started or certain properties will be null

What made this very difficult to figure out is that I couldn’t figure out how to make BasicStatusManager print out error message. I ended up having to use the following code to print everything out.

for(Status status : logger.getLoggerContext().getStatusManager().getCopyOfStatusList()){
    System.out.println(status.getOrigin() + " - " + status.getMessage());
}

There is a separate thread going on as mentioned in the comment above on why LogBack log messages are not printing out. I also have an email thread going on with Nabble. Will post the solution in that thread as soon as I or someone can figure this out.