+ This feature requires a set of null annotations declared with @Target({TYPE_USE}),
+ which JDT ships as version 2.0.0 of the
+ org.eclipse.jdt.annotation bundle.
+
+ With these annotations, nullness can be considered as an intrinsic part of the type system, + allowing the compiler to perform null type checking along with each task of type checking. + This is a major step towards systematically detecting all possible NullPointerExceptions + in a program. +
++ The most obvious benefit is in annotating type arguments of generic types: +
++ +
++ For a comprehensive description of type annotation based null analysis see the online help. +
+
+ While potentially, the new approach could lead to an explosion of the number of annotations,
+ also @NonNullByDefault has become much more powerful, such that programs not using
+ any null values can be fully checked with just a single annotation:
+
+ +
++ The switch from declaration annotations (Java 5) to null type annotations (Java 8) + brings a few unavoidable incompatibilities. Developers already using null annotations + are advised to carefully read the compatibility notes. + Even for those not planning to migrate to null type annotations, the section on + project configuration + has essential information. +
+