7. A hot video prediction method, comprising: storing, by a video comments database, a plurality of video comments submitted by a plurality of users during a period of time in the past; establishing, by a user social network constructor, a user social network of the users according to the video comments; upon receiving a new comment of a new video, determining, by a hot video predictor, a similar theme between the new video comment content and comment content of hot videos that have been popular for the period of time according to the user social network, and predicting whether the new video is going to be popular accordingly; and verifying, the prediction by a social network adaptor, and modifying the user social network by the social network adaptor accordingly.
7. A hot video prediction method, comprising: storing, by a video comments database, a plurality of video comments submitted by a plurality of users during a period of time in the past; establishing, by a user social network constructor, a user social network of the users according to the video comments; upon receiving a new comment of a new video, determining, by a hot video predictor, a similar theme between the new video comment content and comment content of hot videos that have been popular for the period of time according to the user social network, and predicting whether the new video is going to be popular accordingly; and verifying, the prediction by a social network adaptor, and modifying the user social network by the social network adaptor accordingly. 8. The hot video prediction method of claim 7 , wherein the step of establishing the user social network comprises: determining user interest features for each of the users according to the video comments; and establishing a relationship between a pair of the users according to the user interest features; and determining common interests among the users according to the relationship between a pair of users, and establishing the user social network accordingly.