We have developed the Java programming learning support system JPLAS as a Web application using JSP, Servlet, and Java Beans, to support repetitive self-learning of Java programming through automatic verifications of answers from students to assignments. Because the codes in JPLAS have been implemented by students who have newly joined our group and taken over the codes from seniors, their managements and updates have become complicated. At the same time, they do not follow the Web standard including HTML5 and CSS3 that has become popular to realize rich Web clients. In this paper, we propose a draft coding rule to implement codes in JPLAS following the Web standard. By adopting HTML5 and Ajax, this rule makes it possible implementing codes that can be easily maintained by avoiding redundancy.