@Nonnull默认情况下在eclipse / kepler中

Question

In eclipse, it's possible to set not null by default for a single package. Is there any way to set it across all packages, or for a tree of packages?

Edit

I'm talking about the @Nonnull annotations that eclipse respects and polices. At the moment, we are putting them on every function, every variable every parameter. I know we can just set them package wide, by putting the attribute in package-info - but we have hundreds of packages, and it's easy to miss one. I am hoping to be able to set eclipse to say "assume @Nonnull by default, unless @Nullable is specified".

Answer 1

Eclipse can help you detect any packages that are lacking a @NonNullByDefault if you enable the compiler option "Missing '@NonNullByDefault' annotation on package". This option is set to "Ignore" by default, set to "Warning" or "Error" as you like.

See http://help.eclipse.org/luna/topic/org.eclipse.jdt.doc.user/reference/preferences/java/compiler/ref-preferences-errors-warnings.htm?cp=1_4_2_0_3_1

Answer 2

Try this cute little project:

https://code.google.com/p/notnullcheckweaver/

It inserts null checks around every element annotated with @NotNull

Its default setting is @Nullable, though, so you should still annotate your (root) package, to get it to enforce everything except @Nullable annotated elements.

Drawbacks:

• It introduces yet another @NotNull annotation and does not allow others (eg java's own @Nonnull, spring annotations, etc.)
  
• It works through bytecode manipulation and java-agents

Answer 3

Are you sure you want to add @Notnull to every function, every variable and every parameter in your project (keeping in mind that you have hundreds of packages)?

What if you function needs to return null or parameter needs to be null?

I don't think this is a good idea.