In Netbeans click on Source > Inspect. Then you can set the "search scope" (project, current file..). When you click on the "Manage" Button you can uncollapse "JDK 1.5 and later" where you can check the box "Add @Override
Annotation. This helps you finding the missing @Override
Annotations.
But i can't tell you how to find the needless @Override
Annotations..
With maven you can try to add these lines to the maven compiler plugin config (didn't try this at all..):
<compilerArgs>
<arg>-Xlint:rawtypes</arg>
<arg>-Xlint:overrides</arg>
</compilerArgs>