In Development Mode you do have the option to copy in new files and have them auto deployed:
"To auto-deploy an archived application, copy its archive file to the /autodeploy directory. WebLogic Server automatically sets the application’s deployment mode to stage mode.
A deployment unit that was auto-deployed can be dynamically redeployed while the server is
running. To dynamically redeploy, copy the new version of the archive file over the existing file in the /autodeploy directory."
However, that is not the appropriate way to deploy an application in a production environment. In production you have a few options. You can call weblogic deployer with the update parameter:
java weblogic.Deployer -adminurl http://test:7001 -user weblogic
-password weblogic -update -name myapp.ear -upload
-plan c:\localfiles\nuPlan.xml
Or you can simply login to the weblogic admin console:
Deployments -> select your deployment -> Click Update -> choose your new war file