To improve Java programming educations, we have developed a Web-based Java Programming Learning System (JPLAS). To deal with students at different levels, JPLAS provides three levels of problems, namely, element fill-in-blank problems, statement fill-in-blank problems, and code writing problems. Unfortunately, since JPLAS has been implemented by various students who studied in our group at different years, the code has become complex and redundant, which makes further extensions of JPLAS extremely hard. In this paper, we propose the software architecture for JPLAS to avoid redundancy to the utmost at implementations of new functions that will be continued with this JPLAS project. Following the MVC model, our proposal basically uses Java for the model (M), JavaScript/CSS for the view (V), and JSP for the controller (C). For the evaluation, we implement JPLAS by this architecture and compare the number of code files with the previous implementation.