Nobody knows everything. Actually, you are already a mature Java developer. I say so because you can understand my responses.
We Java folks are fighting agaist bugs everyday....
Be sure to improve your English. One of my friends is from Japan and he is a PhD from Tokyo Univeristy. His english is terrible. He first immigrated to Canada 4 years ago. He taught himself some VB and began to hunt for jobs... many sad stories. Later he came to USA and attended some training schools. Then he beagn to hunt for jobs ago. He experienced about 49 job interviews and got an offer. He earns much less than he did in Japan.... Several years have passed but his English is still awkward. I feel very diffiuclt to understand his English because of his accents.
Hope you can improve your English as much as possible before you come to Canada.