This paper presents the design and implementation of a pattern-based J2EE application development environment aimed at streamlining the development process, enhancing code quality, and improving maintainability. We begin with an exploration of the fundamental principles of J2EE and the role of design patterns in software engineering. This is followed by a detailed discussion on the selection and application of various design patterns specifically tailored for J2EE, such as Singleton, Factory, Data Access Object (DAO), and Model-View-Controller (MVC).