Abstract: Embodiments of the present application provide an XML based custom code generating method and an XML based custom code generator, a computer program product and a computer readable medium. The method comprises: obtaining code source information, user custom template file information and a prestored code output format rule; preprocessing the code source information, classifying the code source information and storing the same into a code source container; dynamically replacing a corresponding description part in the user custom template file with the corresponding classified code source information stored in the code source container; and outputting codes in the replaced user defined template file according to the prestored code output format rule. With the method and generator, repeated code can be automatically implemented during the development process, custom extension can be flexibly implemented, the workload of engineers can be reduced and the stability of the system is improved.