在其他应用程序运行时，如何防止Java程序滞后？

Question

I wrote a simple code in Java that uses the Robot class to move the mouse according to some conditions.

Although the code works nicely, there seems to be a 'lag' when other applications are running.

I think Java has some issues posting system messages.

Is there a workaround to avoid this?

Answer 1

Before you start thinking about reducing the lag, you must first understand it's causes. I'll present the answer(s) in a fashion in which you can understand the "why" along with the "what to do".

By your description that the lag only occurs when other programs are running along with your robot, the most likely causes for the lag are:

---

Lack of system resources - Too many things running at the same time, consuming too much memory/processing-power, thus making the OS slow-down some programs in order to be able to run the others.

What to do: To try to fix such issues, you can try to optimize your code, to make it use less memory/processing power, thus reducing the cause of the lag, with implicitly reduces the lag itself. Unfortunetly tough, it's hard to legally do the same for any 3rd party programs, so the lag can hardly be completely removed if the concurrent applications are not yours.

---

Concurrency regarding a non-replicable, non-shareable component - One or more components that cannot be accessed by more than one process at a time and that cannot be cloned into multiple instances needs to be used by more than one process that is running. While one process takes control of it, any other processes have no choice but wait for the component to be freed.

What to do: In this case, there hardly is any legal method other than to reduce the concurrent process's priority while increasing your's (effectively slowing them down in order for your program to run faster), or shut them down completely.

How to do: To increase your process's priority, this is the code to set it at 80% (default is usually 50%), inset at your main() :

Thread.currentThread().setPriority((int)(Thread.MAX_PRIORITY*0.8));

Note: You can set your process to "never" let go of whatever components it needs, using Thread.MAX_PRIORITY without multiplying by 0.8 , but that is unrecommended , as it will pretty much pause any process that requires the components (quasi-same to shutting them down while yours is running), and if your program hangs, for whatever reason, so will those, as the components are never released.