rspec/rules/S2789/java/rule.adoc

The concept of ``++Optional++`` is that it will be used when ``++null++`` could cause errors. In a way, it replaces ``++null++``, and when ``++Optional++`` is in use, there should never be a question of returning or receiving ``++null++`` from a call.


== Noncompliant Code Example

----
public void doSomething () {
  Optional<String> optional = getOptional();
  if (optional != null) {  // Noncompliant
    // do something with optional...
  } 
  Optional<String> text = null; // Noncompliant, a variable whose type is Optional should never itself be null
  // ...
}

@Nullable // Noncompliant
public Optional<String> getOptional() {
  // ...
  return null;  // Noncompliant
}
----


== Compliant Solution

----
public void doSomething () {
  Optional<String> optional = getOptional();
  optional.ifPresent(
    // do something with optional...
  );
  Optional<String> text = Optional.empty();
  // ... 
}

public Optional<String> getOptional() {
  // ...
  return Optional.empty();
}
----