建構一個在EJB架構中的Transaction系統

Abstract

Enterprise JavaBeans（EJB）架構是被設計用來利用現存在伺服器端的原件組裝成一套具有擴充性、安全性、靈活性、分散式和輕薄短小的應用程式。支援transaction功能是EJB架構的特徵之一。本篇論文實作一個建構在EJB架構的Transaction系統。這個Transaction系統允許程式開發者利用多個enterprise beans在一個transaction中同時對多個資料庫作存取。甚至，這些資料庫可能位在不同的伺服器裡。除了管理transaction外，這個Transaction系統還能自動根據enterprise beans的特性來執行transaction動作，包括開啟、完成和回返一個transaction。因此，程式開發者便不需要在程式中明確的區分出transaction的範圍，而且enterprise beans的撰寫也變成更加簡單。

The Enterprise JavaBeans (EJB) architecture is designed to enable building one scalable, secure, flexible, distributed and chin-client applications as reusable and server-side components. The EJB architecture was proposed to support for transactions. This thesis presents an implementation of a transaction system of EJB architecture, which allows application developers to invoke enterprise beans to update data in multiple databases in a single transaction. These databases can be distributed in different servers. In addition to manage the transactions, the transaction system could automatically demarcate a transaction on behalf of the enterprise bean, including begin, commit, and rollback it. Hence, the application developer need not explicitly specify transaction demarcation code and the enterprise beans are simpler to develop.