Once application clients are downloaded, they remain on the client until removed manually. The Java Web Start control panel provides a simple interface you can use to discard downloaded application clients that used Java Web Start. When you undeploy an application client, you can no longer use Java Web Start, or any other mechanism, to download the application client. If you try to launch an application client that was previously downloaded even though the server side of the application client is no longer present, the results depend on whether the application client has been written to tolerate such situations.
You can write your application client to detect failures in contacting server-side components and to continue running anyway. In this case, Java Web Start can run an undeployed application client as it is cached locally. For example, your application client can be written to catch and recover from a javax.naming.NamingException in locating a resource or a java.rmi.RemoteException in referring to a previously-located resource that becomes inaccessible.