intellij idea does not see java 9 standard classes

问题

I've got a maven project that uses Java 9. It imported into IntelliJ IDEA 2017.2.3 Community.

But for some reason it cannot find standard java classes like String or Float. For example

When I try to Setup Project JDK it changes nothing

What is the problem?

module-info looks like this

module com.lapots.breed.platform.cloud.javacloudsample {
    requires spring.boot;
    requires hibernate.jpa;
    requires spring.web;
    requires spring.boot.autoconfigure;
}

Project itself is there java-cloud-sample

来源：https://stackoverflow.com/questions/46094287/intellij-idea-does-not-see-java-9-standard-classes