1. First make sure that your dependent, it has been added and the success of the project started, is not being given.
2. The individual classes are then prompted to get out of that, there is the red line on the code
This time can determine the general idea of the cache is out of the question. Students should pay attention will find that even the local maven jar emptied warehouses have been deleted, open the case of the fixed idea, and the idea will not find jar own warehouse has gone. That is because the idea is to rely on its own set of cache configuration. This cache can greatly improve the efficiency of the idea, but sometimes go wrong. For example, a warehouse of a jar package which adds a class, decompile own jar package and found that a class, but the idea is the lead project which not. Because the idea that this jar cache configuration has not changed, no update, so how can not lead project inside.
This time next reimport, invalidate, restart the situation is not so that online said, in relation to the project idea to delete the configuration file. After you remove so that idea reload maven dependency. But they could not bear to delete the profile, because there are a lot of project information, such as annotation templates, ah, ah startup parameters, and so on. This will only delete the cache configuration file idea about the project dependencies, reload the project relies after .idea folder libraries under, can be deleted. If there is a disservice, hope feedback about the comments area.