To be certain, get 2 letter from your friend in China, naming each of you separately. These will go with visa application. China goes however they wish, when they wish, so the letters are safeguards. My friend had a visa problem herself, so she got her ex-husband to invite us to China. I felt comfortable having that. The rest of the details will be explained by others here. (I'm DL, so I can't help with more)