C++ does include hash functions. Of course, most will just use std::unordered_map.
That isn't part of the language, that's part of the standard library. Just the same as java, which has a standard hashing function, AND hash table/map.
Ultimately, where does the language end, and the standard library begin? Whats the real difference? Yeah, so C++ and Java don't have built in syntax for hash tables. That's it?
Well neither does C, C++ as well. Nor does Scala actually.
There are a lot of good things about Java, namely the JVM, interfaces, great libraries, reflection and code generation, etc, etc. For example libraries like jmock/etc.