For @Nullable type annotations (such as
org.checkerframework.checker.nullness.qual.Nullable), @Nullable byte[] means
a ‘non-null array of nullable bytes’, and byte @Nullable [] means a ‘nullable
array of non-null bytes’. Since primitive types cannot be null, the former is
incorrect.
Some other nullness annotations (such as javax.annotation.Nullable) are
declaration annotations rather than type annotations. Their meaning is
different: For such annotations, @Nullable byte[] refers to ‘a nullable array
of non-null bytes,’ and byte @Nullable [] is rejected by javac. Thus, this
check never reports errors for usages of declaration annotations.
See also: https://checkerframework.org/manual/#faq-array-syntax-meaning
Suppress false positives by adding the suppression annotation @SuppressWarnings("NullablePrimitiveArray") to the enclosing element.