一个程序中有多个JVM实例

Question

I have a JFrame and a JTabbedPane

The JTabbedPane has JPanel s, and each JPanel has an Applet .

If I load the applet, and then close it, the CPU usage drops but the RAM usage stays high. So in order for me to correctly release the RAM, each JPanel / Applet has to have its own JVM which I can terminate. The code of the Applet isn't mine, but that's how it was made, simply destructing it won't work.

So what I'm asking is, how can I attatch a new JVM to each JPanel as I add one?

Answer 1

In order to accomplish this you would need to have a wrapper application capable of starting a new instance of the JVM (forking a new process) each time you want to open one of your JPanel/Applet things. You could do this by calling Runtime.exec() and invoking a new instance of the JVM, but honestly all of this smells a little bit to me. The JVM really isn't designed for this and I think what's more likely is you have a memory leak somewhere that isn't properly handled.

Answer 2

I don't think you can have more than 1 instance of the JVM running for any given application, as detailed by the Runtime Class

However, I believe if you remove all of your references to each Applet when you shut it down, you can call System.gc() to clean up the memory so that you can use it for something else within that Java application. However, keep in mind that your RAM usage will not go down, as the JVM heap is allocated at startup and, so far as I know, cannot be resized during execution. For information on how that works, see JVM Option: Xmx Allocation