Unboxing is unnecessary as for Java 5 and later, and can safely be removed.
Examples:
Integer i = Integer.valueOf(42).intValue();
→ Integer i = Integer.valueOf(42);
int k = Integer.valueOf(42).intValue();
→ int k = Integer.valueOf(42);
(reports only when the Only report truly superfluously unboxed expressions option is not checked)
Use the Only report truly superfluously unboxed expressions option to only report truly superfluous unboxing, where an unboxed value is immediately boxed either implicitly or explicitly. In this case, the entire unboxing-boxing step can be removed. The inspection doesn't report simple explicit unboxing.
This inspection only reports if the language level of the project or module is five or higher.