Java 8 Optional Map

If a value is present this method returns a sequential stream containing the value or else returns an empty stream. It is a public final class and used to deal with nullpointerexception in java application. It makes total sense for java.

This makes the code more readable because the facts which were hidden are now visible to the developer. You must import java.util package to use this class. It provides methods which are used to check the presence of value for particular variable.

Java initialize map with values in one line;

I'm trying to get into optional issues in java 8. I've written an extremely simple program, consisting of one class and main() method. Similar to the filter () method, this method returns an optional object with a value after conversion. Java 8 optional map or else.