Java - 如何访问另一个正在运行的应用程序中的类

In my scenario, I have a server running which waits for a client to make a connection. It is necessary for a client to instantiate the connection because the computer I'm looking to communicate with has more restrictive network security than I do. The client will connect to me daily. So I have a jar file and process running that handles this. Server side on my end, and client side on the other end. Next, I have a web page running, and when a user clicks a specific button, I need to tell the Server app, "okay, now send data to the client".In my scenario, I have a server running which w