I was running my application in JDeveloper when I noticed log messages in the console for a different application, let's call it OldApp. I stopped and started the my application server, the WLS server, re-ran my application, and still I'd see messages for OldApp. I shut down JDeveloper, restarted, and still when I ran my application, I'd see the OldApp's messages

Well, it turns out that at some point in time the OldApp was not properly undeployed. To really stop OldApp, I had to:

Go to http://127.0.0.1:7101/console.

This deployed the console app where you configure WLS. By default the login credentials are:

username: weblogic

password: weblogic1

I clicked on Deployments and I saw that OldApp was still running. I selected the checkbox next to OldApp and clicked on the Stop -> Force Stop Now.  Now when I run my application, I do not see the OldApp log messages.