When software developers create software, they usually want to attach some customizable functions to their software. These functions are usually implemented by reading a customization file or by manipulating a GUI. In this paper we describe a system called "jShio". This system serves as a customization language compiler-compiler, similar to the Unix tool Yacc. The user creates a specification of the customization language and jShio generates a Java subsystem that can process a customization data in appropriate data structures. jShio also supports customization based on design pattern. Support for customization by a GUI is planned for the future.'