问题:

is it possible to use run a java class in command line to run a certain class or function in a running swing?

such as , when java Test asd will setText a running swing Jlabel to asd

回答1:

The most straight forward way is to create an RMI method call.

It's built into java from the beginning, reasonably simple and lightweight.

回答2:

The two programs run in separate processes. You will need to create an interface between the processes (or as Matthew put it: implement inter-process communication). There are millions of ways to achieve this, just to name a few:

Create a file-based interface (Test will write into a file and JLabel will read that file)
Create a TCP/IP connection between the two
Create a HTTP connection between the two (JLabel may run a glassfish thread or something like that)
Create a JMS connection
Create an RMI method call
Create a Webservice (again with JLabel running glassfish)
Many more...