It depends on the person and their exposure to java. If you can read through books quickly and grasp things fast, you will be able to acquire the certificate faster. If you have around 3-4 hours to spend everyday then it might take you around 3 months - 4 months. That is just a rough estimate. Good luck
Hi all again, and thanks a lot for your fast replies. I forgot to say that I work with java since late 2004 (11/2004) as junior consultant. I worked with J2EE in my first occupation, and since June 2005 I began to work with JSE 5.0. As you know, working on some technology (JSE 5.0) leads you learn very quickly what you need, but sometimes you leave behind the basics.