(The school's second-hand trading website adopts the bs architecture model development. The system is mainly aimed at conducting a transaction and online exchange of second-hand items shelved by students, which facilitates timely management of second-hand items. It is also a simple e-commerce website. The website is mainly about colleges and universities The reference and learning of the source code of the computer graduation project also provides an outstanding learning platform for programming enthusiasts. This material includes the following attachments:)