jenkinsci/hpe-application-automation-tools-plugin

It is highly recommended not to use wildcard types as return types. Because the type inference rules are fairly complex it is unlikely the user of that API will know how to use it correctly.

Let's take the example of method returning a "List<? extends Animal>". Is it possible on this list to add a Dog, a Cat, ... we simply don't know. And neither does the compiler, which is why it will not allow such a direct use. The use of wildcard types should be limited to method parameters.

This rule raises an issue when a method returns a wildcard type.

Noncompliant Code Example

List<? extends Animal> getAnimals(){...}

Compliant Solution

List<Animal> getAnimals(){...}

or

List<Dog> getAnimals(){...}

It is highly recommended not to use wildcard types as return types. Because the type inference rules are fairly complex it is unlikely the user of that API will know how to use it correctly.

Let's take the example of method returning a "List<? extends Animal>". Is it possible on this list to add a Dog, a Cat, ... we simply don't know. And neither does the compiler, which is why it will not allow such a direct use. The use of wildcard types should be limited to method parameters.

This rule raises an issue when a method returns a wildcard type.

Noncompliant Code Example

List<? extends Animal> getAnimals(){...}

Compliant Solution

List<Animal> getAnimals(){...}

or

List<Dog> getAnimals(){...}

When two methods have the same implementation, either it was a mistake - something else was intended - or the duplication was intentional, but may be confusing to maintainers. In the latter case, one implementation should invoke the other. Numerical and string literals are not taken into account.

Noncompliant Code Example

private final static String CODE = "bounteous";

public String calculateCode() {
  doTheThing();
  return CODE;
}

public String getName() {  // Noncompliant
  doTheThing();
  return CODE;
}

Compliant Solution

private final static String CODE = "bounteous";

public String getCode() {
  doTheThing();
  return CODE;
}

public String getName() {
  return getCode();
}

Exceptions

Methods that are not accessors (getters and setters), with fewer than 2 statements are ignored.