Java Log Viewer

Just wanted to say that I've finally found a tool that I can get along with just fine...

It's called LogExpert (see http://www.log-expert.de/) and is free. Besides the usual tail function, it also has a filter and a search function - two crucial things that are missing from BareTail. And if you happen to want to customize the way it parses columns further, it's dead simple. Just implement an interface in .NET and you're done (and I'm a Java/Flex programmer...)

You didn't mention an OS, so I'll mention this though it is only on Windows.

Bare Metal Software makes a product called BareTail that has a nice interface and works well. They have a free version with a startup nag screen, a licensed version with no nag, and a pro version with additional features. It has configurable highlighting based on matching lines against keywords.

They also have a BareGrep product too, which provides similar grep capabilities. Both are excellent and very stable and better than anything I've seen on Windows. I liked them so much I bought the bundle with both pro versions for $50.

You can try logFaces, it has fantastic real-time log viewer based on eclipse-like design.

Disclosure: I am the author of this product.

I've always used 'tail -f | grep re' or occasionaly 'awk'.

LogSaw based on Eclipse and free. Log4j log file analyzer, simple to use with easy filtering. Supports several flavors of log4j log files: JBoss, Log4j pattern layout, Log4j XML layout, WebSphere.

Works like a charm. After couple of hours googling and trying several recommended free log4j viewers, this one was pleasant surprise. Have tried Chainsaw, BareTail, Insight, LogExpert, logview4j.

It is released weeks ago, and I guess still builds its way up on google.

I've rolled out Splunk (http://www.splunk.com/) for log viewing and searching with great success. The free version can be used locally and the paid version can collect all your logs into one location. We use it mostly for Log4J logs but with lots of other formats as well.

Beyond tail and grep support (without needing to know grep...) it automatically indexes logs and allows easy analysis (e.g. # of events in last xx timeframe) as well as basic charting, alerting, and event aggregation.

I won't say that the app is perfect or that the company has matured yet. But I don't hesitate at all to recommend that you try it.

Depending on what platform you are running on and what other log viewing tools you have available, you can just use the appropriate log4j appender (syslog, Windows Event Logger) and just use your platform log viewing tools.

Other than that I have usually seen custom solutions developed.

Something that will drive your solution is what your overall system is like. Are you trying to aggregate logs from several computers? Or just view the logs from a single remote process?

You may want to use a custom log viewer that just works on files. I like Kiwi Log Viewer or Ganymede (an Eclipse plugin), but it's not hard to put a simple Swing app together that reads from the socket.

Take a look to http://jlogviewer.sourceforge.net/ or http://sourceforge.net/projects/jlogviewer/ Java log viewer is lightweight GUI to easily view the java application logs generated by the "java.util.logging" package. It's open source!!