//CTRL+F12 can not only locate the method, but also locate the position of the class. Everyone knows this detail, but it is not used. It is very efficient to save the mouse operation;
//View by package
// first look at the interface
//CTRL+ALT+B to see the implementation class
//CTRL+H to see the inheritance relationship
//ALT+7 / 4 View internal details
//CTRL+F12 to view the class method
//CTRL+ALT+F7 to see the calling location
//ALT+SHIFT+ALT+U View class diagram
//CTRL+ALT+SHIFT+H View call track