Search code examples
javaannotationsjava-8checker-framework

Java scoping construct cannot be annotated with type-use

I want to annotate a fully qualified class name with @Nullable-annotation (from the Java Checker Framework), e.g.:

class Demo {
    private transient @Nullable org.apache.lucene.search.Query cached_results;

    // ...
}

However this results in the error:

scoping construct cannot be annotated with type-use annotation: @checkers.nullness.quals.Nullable

How can I annotate fully qualified class names?

Solution

  • The Java language specification (draft for version 8) §8.3 specifies a "UnannClassType" as

    UnannClassType:
    Identifier [TypeArguments]
    UnannClassOrInterfaceType . {Annotation} Identifier [TypeArguments]

    Thus, you need the declaration:

    private transient org.apache.lucene.search.@Nullable Query cached_results;

    Or in the augmented java 7 compiler of the checker framework:

    private transient org.apache.lucene.search./*@Nullable*/ Query cached_results;

    NOTE: normal Java compilers ignore /*@Nullable*/.