Annotation Type Var

@Target({FIELD,PARAMETER,LOCAL_VARIABLE})
@Retention(RUNTIME)
@IncompatibleModifiers(modifier=FINAL)
public @interface Var

The parameter or local variable to which this annotation is applied is non-final.

Most references are never modified, and accidentally modifying a reference is a potential source of bugs. To prevent accidental modifications, the accompanying Error Prone check prevents parameters and local variables from being modified unless they are explicitly annotated with @Var.

Since Java 8 can infer whether a local variable or parameter is effectively final, and @Var makes it clear whether any variable is non- final, explicitly marking local variables and parameters as final is discouraged.

The annotation can also be applied to fields, to indicate that the field is deliberately non-final.