[SLING-4377] Add JSR305 nullness annotations to Sling API

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: API 2.9.0
• Component/s: API
• Assignee: Konrad Windszus
• Reporter: Konrad Windszus
• Created: 02/Feb/15 08:55
• Updated: 22/Oct/20 15:44
• Resolved: 17/Feb/15 10:34

Description

Since consumers of the Sling API always have to keep in mind whether a null-check is necessary it would be good to add JSR 305 annotations to the API.

See also http://www.mail-archive.com/[e-mail]/msg42199.html.

At least Eclipse as well as Findbugs are supporting those and Oak Solr is using those already (https://issues.apache.org/jira/browse/OAK-2303).

Only the following 2 annotations should be used:

1. @Nonnull, for return values which are not supposed to be null or parameters which must not be null.
2. @CheckForNull, for return values wich may be null null.
   Those are the only ones being supported by both Eclipse and Findbugs (compare with http://sourceforge.net/p/findbugs/bugs/1355/)

@Nullable is basically ignored by Findbugs (http://findbugs.sourceforge.net/manual/annotations.html) and should therefore not be used. The package annotation for the default handling should also not be used (because either @Nullable or @CheckForNull is ignored by Eclipse then.

Issue Links

• is related to: SLING-6609 Fix JSR305 annotations for ValueMap.get
• is related to: SLING-6602 Add JSR305 nullness annotations to AbstractResourceVisitor
• is related to: SLING-6991 Add JSR305 nullness annotations to Sling JCR API
• is related to: SLING-4737 Add JSR305 nullness annotations to Sling Models API
• is related to: SLING-5608 Manage version of JSR-305 dependency in Sling parent
• is superceded by: SLING-7798 Switch from JSR-305 annotations to JetBrains Nullable/NotNull annotations
• relates to: OAK-37 Use nullability annotation to enforce/document API contract
• relates to: SLING-4609 Add JSR305 nullness annotations to Validation API