Simon Phipps said that existing work towards GPLv3 had been "extraordinary and effective" and he said he is "frankly amazed by the criticisms".
Phipps' comments are surprising given that when Sun decided to release Java under the GPL last month it chose to work purely under GPLv2. They are also noticeable because of Phipps' senior position at a commercial software vendor.
"Sun has been engaged directly in the GPLv3 process since it started... and we continue to take a close and positive interest in the proceedings. My personal view is that the GPLv3 process has been extraordinary and effective so far in taking a somewhat partisan initial draft and evolving it into a solid licence," said Phipps in a blog entry.
He added, "I am frankly amazed by the criticisms that have [been] levelled at the GPLv3 process. They seem to ignore the incredible and positive way it is evolving and just find fault with things that are already the subject of work... I would be very surprised if the final GPLv3 was not an effective tool for some of the communities Sun sustains or will initiate in the future."
But Phipps also sought to justify Sun's decision to release Java under version 2.
He wrote: "Sun could not in good faith commit to use a licence sight-unseen for such an important code-base. It's used on four billion devices... and the risk — however slight — that the GPLv3 might prove harmful to them can't be taken. Committing to it when it's not finished does not seem responsible stewardship.
He added: "I hope we can use it, but I can't express that hope by committing in advance. So, for now, the Java platform will be licensed under just the GPLv2. Maybe we could have delayed the Freeing of the Java platform until the new licence was ready, but we felt that was too long to wait."
The GPLv3 process is due to be completed in the spring.
Linus Torvalds has publicly said he will not convert Linux to version 3 because he has doubts over the proposals for digital rights management (DRM) provisions in the new version.