Can we add structures in Java?

I was asked this question in an interview and couldn't answer it I hope you can help me

The question is: why don't Java people add support for structures? Why is it impossible to add value types allocated on the stack to Java?

I think the previous java version should have some backward compatibility problems? But I can't ask any questions

Solution

Although Java does not allow stack allocation, it does use something called escape analysis

Found a link to this: http://www.ibm.com/developerworks/java/library/j-jtp09275/index.html