(J2HE is a Java language specially developed for embedded military devices such as mobile phones. This paper first makes a basic introduction to mobile development, focusing on the operating system used in mobile devices. From the development of J2ME, this paper introduces the system framework of J2 border and the current situation and prospect of J2HE. A general explanation of L) 2HE is given. A simple example is given to make readers have a deeper understanding of J2ME. This document includes the following annexes:)