@ParametersAreNonnullByDefault
The @ParametersAreNonnullByDefault
annotation helps you define that all method parameters in a class or a package have @NotNull
semantic, unless they are explicitly annotated with the @Nullable
annotation.
The @ParametersAreNonnullByDefault
annotation can be used with a package, a class, or a method.
To use the annotation, add the jsr305
library to module dependencies:
Open the Project Structure dialogCtrl+Alt+Shift+S, and go to .
Click Add and select .
In the IntelliJ IDEA home directory, select lib\jsr305.jar.
(Optionally) In the next dialog, you can modify library name and level.
Apply the changes and close the dialog.
Once you add the JAR to your project, you can start using the @ParametersAreNonnullByDefault
annotation. For example, consider the following code:
If you annotate the sort()
method with @ParametersAreNonnullByDefault
, IntelliJ IDEA immediately recognizes that if
statement is extraneous, and reports about the condition that is always true.
However, if you annotate the parameter of the method sort()
as nullable, you will see no inspection messages.