Well that is arguable. If you stay within JVM, you can use your Java code from other languages like Clojure and Scala. To some extent you can use Scala and Clojure code from Java. But you can't really use Java code from Python or Ruby unless you work with Jython or JRuby.
So, I'd put Java in the "dead end language" bin. You can use C code from Java (via JNI) but it's not practical to do it the other way.
Except for Java, where you can reuse code directly with JVM-compiling stacks like Clojure.