When importing maven dependencies for GraphQL, got a error (The type java.util.Optional cannot be resolved. It is indirectly referenced from required .class files). I have a class in my project which is extending SimpleGraphQLServlet. The SimpleGraphQLServlet implementation is using the Java.Util.Optional class but this class is not found in java 7 library. I can't upgrade my project java version to 8. Can anyone please provide me a solution to this problem.
(This question is not duplicate as intelliJ Optional class issue. This is related to Graphql library)