{"id":139,"date":"2007-03-30T02:51:00","date_gmt":"2007-03-30T02:51:00","guid":{"rendered":"https:\/\/zofxare.com\/zofxare\/blog\/2007\/03\/30\/java-finalize-function\/"},"modified":"2007-03-30T02:51:00","modified_gmt":"2007-03-30T02:51:00","slug":"java-finalize-function","status":"publish","type":"post","link":"https:\/\/zofxare.com\/zofxare\/blog\/2007\/03\/30\/java-finalize-function\/","title":{"rendered":"Java finalize function"},"content":{"rendered":"

Using peer classes and implementation pointers to call C++ classes from java using JNI seems to work out ok so far. Forget the finalize function I talked about in my last post though. Apparently sometimes the finalize function is called and sometimes the finalize function is not called. It’s very unpredictable. This behavior was verified when I did some debugging. My finalize function never got called, so the implementation pointer I created in the JNI was never released.
Instead you need to specify a Java function in your peer class to release the memory in the JNI and explicitly call it yourself. For my java application, I have a JFrame to which I added a windowClosing action listener<\/a>:<\/p>\n

addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
\/\/ call the destroy method of the Java peer class
peerclassname.destroy(); <\/p>\n

System.exit(0); \/\/calling this method is a must
}
});<\/p>\n

This function is automatically called when the JFrame exits. The destroy function in the peer class calls the JNI destroy function which releases the C++ pointer.<\/p>\n