I my previous reply, I have said that your boyfriend can't sponsor for your extension of visa (in fact, you get a visa with 0 entry), but if you insist on doing so, you can provide the copy of your boyfirend's passport, residence permit or work permit, your original passport and copy of your work visa, one completed visa application form affixed with one recent photo, then go to the local Exit & enter department under the Shanghai Public Security Bureau to apply for 1 month visa with 0 entry.