Java 8 introduced the Optional class, which is a container object that may or may not contain a non-null value. It is a way of representing an optional value, which means a value that may or may not be present. The advantage of using Optional is that it can help avoid null pointer exceptions, which can be a common source of bugs in Java code.
To use Optional, you create an instance of the class and pass in the value you want to wrap. If the value is null, then you create an empty instance of Optional. You can then use various methods to check whether the Optional contains a value or not, and to access the value if it does.
For example, consider the following code snippet:
Optional<String> optionalName = Optional.ofNullable(getName());
if (optionalName.isPresent()) {
String name = optionalName.get();
System.out.println("Hello, " + name + "!");
} else {
System.out.println("Hello, stranger!");
}
In this example, getName() is a method that may or may not return a non-null value. We create an Optional instance using Optional.ofNullable(), which will create an empty Optional if getName() returns null. We then use isPresent() to check whether the Optional contains a value, and if it does, we use get() to access the value and print a message.
Another advantage of using Optional is that it makes your code more explicit about the possibility of a value being absent. Instead of relying on a null value to indicate an absence of value, you can use Optional to make it clear that a value may or may not be present. This can make your code more readable and easier to reason about.
In summary, the Optional class in Java 8 provides a way to represent optional values and avoid null pointer exceptions. It can make your code more explicit about the possibility of a value being absent, and can make your code more readable and easier to reason about.
