- Why Optional?
- How many times in our development career, we have troubles with "NullpointerException"?
- To avoid this we end up adding lot of boiler plate code checking each and every variable in nested object.
- To make this clean, Java Optional can be used effectively.
2 . Java 8 optional different methods available on Optional object:
- get
- isPresent
- filter:If a value is present, and the value matches the given predicate, return an Optional describing the value, otherwise return an empty Optional
- map
- orElse
- orElseGet
- orElseThrow
3 . Java 9 Optional new methods
- stream
- ifPresentOrElse
- or