Container function extension of Spring source code analysis (2)

     I plan to change jobs recently and start preparing for exams again. During the exam, the source code will be asked, so I will passively read it again. It used to be driven by interest, but now it is driven by interests, which is unhappy. Something like source code is not a scarce resource, and it takes time to see results. Why do interviewers like to ask these questions? If some interviewers regard the source code as too important, then it is too low. Forget it, don't complain, let's go to the flow chart.