Java 8's Optional Mastery: Nulls Handled Smartly-Null Handling with Java Optional

Example

optionalEmail.ifPresent(email -> System.out.println("Email available: " + email));

Scenario

Used when an action should only be performed if a value is present. For instance, you might want to log or process a user's email only if it's found in the database.

Example

String email = optionalEmail.orElse("[email protected]");

Scenario

Applies when a default value should be returned if the Optional is empty. This is useful in configurations or settings where defaults are common.

Example

String email = optionalEmail.orElseGet(() -> fetchDefaultEmail());

Scenario

Similar to `orElse`, but the default value is supplied by a method call. This is more efficient if obtaining the default value is costly and should be avoided unless necessary.

Example

String email = optionalEmail.orElseThrow(() -> new IllegalStateException("Email not found"));

Scenario

Used when an exception should be thrown if the Optional is empty. This is often employed in methods where returning a null or default value is considered invalid.