1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
/** Test cases for Rule #6: "Avoid using Optional in fields, method parameters, and collections." */
public class Marks6 {
// :: warning: (optional.field)
Optional<String> optionalField = Optional.ofNullable(null);
// :: warning: (optional.parameter)
void optionalParameter(Optional<String> arg) {}
Optional<String> okUses() {
Optional<String> os = Optional.of("hello world");
return os;
}
void illegalInstantiations() {
// :: warning: (optional.as.element.type)
List<Optional<String>> los = new ArrayList<>();
// :: warning: (optional.as.element.type)
List<Optional<String>> los2 = new ArrayList<Optional<String>>();
// :: warning: (optional.as.element.type)
Set<Optional<String>> sos = new HashSet<>();
}
}
|
