Java rose to prominence in the early and the mid 90s by promising the 'code once run anywhere' doctrine. But, this promise has been largely unfulfilled..... Java is the only industry proven cross platform development language....
Java rose to prominence in the mid '90s (as no one outside of Sun used it before the mid-'90s) not because of the promise of WORA, but because people believed that it was less painful than C++ for many applications. (If you're cynical, it's also because the one-ring circus which is the JCP piled lots of companies into the everything-must-be-in-the-standard-library clown car because no matter how cramped things were, none of them wanted Microsoft to own any more de facto standards.)
While I'm sure there are a fair few Java developers who write code on platforms other than their platforms of deployment, cross-platform development, I don't believe that a significant number of stakeholders really care that, in theory, you can deploy your web application to a different platform. I mean, when you have the alphabet soup of Java APIs and XML applications spitting out HTML, what's really important is that HTML is cross-platform, not that the bugs in Java 1.1 or maybe 1.2 these days are about the same on Solaris as they are on Windows.
(Or maybe I'm just bitter that I haven't burned my knees lately crouching over a Macbook Pro in some coffee shop with latte foam slowly congealing in my soul patch.)