It is a bad practice to use Sun's proprietary Java classes?

Question

The compiler display warnings if you use Sun\'s proprietary Java classes. I\'m of the opinion that it\'s generally a bad idea to use these classes. I read this somewhere. Ho

Answer 1

I recently had a case that showed a real-world problem you can hit when you use these classes: we had code that would not compile because a method it was using on a sun.* class simply did not exist in OpenJDK on Ubuntu. So I guess when using these classes you can no longer say things like 'this works with Java 5', because it will only work on a certain Java implementation.