Go to Tools> Options> Editor> Tips. Then select “Java” if it is not already. You will see a long list of warnings. Expand the standard Javac Warnings item and you will see "unverified" there. You can click it to activate it, or even better, click "Standard Javac Alerts" to activate all of them.
It took about a minute for Netbeans to actually apply the changes; I tried many times to rebuild my project and reset the parameters before it worked.
toto2 source share