How to Change log4j Configuration When Packaging

Question

I have a fairly simple Java application that is being distributed out to users as an executable JAR file. In order to track usage and assist in diagnostics, I want to add logging capability to the application but, from one execution to the next, I can never be sure where the users are going to be running this application. In order to make this work, I have configured my application to use a log4j socket appender - no matter where the user is running this application, messages are sent to the socket and properly logged, which is perfect. What I'm running into now, though, it that I would prefer to use different log4j configurations when I am running locally vs. when I deploy this application into production. When running locally (from my IDE, IntelliJ), I would prefer to use a console appender for a couple reasons: - It's trivial to see what is happening. - Should I be developing without an Internet connection, I don't want to hang up on not being able to connect. - I don't want to clu…

Accepted Answer

Here's a simpler approach to your problem...

Put two log4j.properties files under `src/main/resources` directory, like this:-

```
src/main/resources
|- log4j.properties 
|- log4j_dev.properties 
```

`log4j.properties` contains the production configuration, and by default, Log4J will automatically pick this file up because you are using the standard file name.

`log4j_dev.properties` contains the development configuration. To ensure IntelliJ picks this up during development, you will overwrite the log configuration using `-Dlog4j.configuration=<configuration-file>` VM option. I attached a screenshot on how you might configure this using IntelliJ:-

How to Change log4j Configuration When Packaging

Solution

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