Design And Implementation Of A Marine Data Integration System Prototype Based On J2EE And XML

It is self-evident that the ocean is extremely important to the global environment to the subsistence of human beings. Due to a rather short history of about one hundred years and high cost of marine observation and survey, the marine data information available today is extraordinary precious to us. However, the data resources are characterized by such features as distribution, heterogeneity, complexity and large size, etc. How to realize the dynamic integration of the distributed heterogeneous information based on the web and enable the users obtain valuable data by manipulating and analyzing the multitudinous marine data efficiently and pellucidly has already become an important research direction in the fields of database and marine science nowadays.As a meta-language, XML has actually become the standard language for data expressing and exchanging on the Internet. XML is powerfully capable of data describing. It is a kind of structured descriptive language, adopting the tree-like memory structure and allowing the deep-structure-embedded expression. All of these characteristics make it extremely suitable to describe uniformly the marine data with complex structures so as to simplify the data exchanging and realize the data sharing. At present, the research and application of MarineXML, which is the XML-based marine data exchange format, have already developed in the world. Up to now, it has made some progress.This thesis begins with an introduction to XML language and the characteristics of marine data as well as the basic structure of MarineXML. And then it is followed by a brief introduction to the common technologies about the integration of data resource based on Web. On the basis of these,a multilayer B/S-structured marine heterogeneous data source integration system framework based on virtual XML documents is presented. The system framework can be divided into four layers: presentation layer, web layer, application layer and data layer. The thesis illustrates in detail the function, interrelation and realization algorithms of each module on the application layer, which is the whole system' s kernel. In addition, the thesis proposes how to construct the system prototype with J2EE and XML technology. The basic idea can be depicted as follows: describing the marine data and establishing global view module with XML, realizing the interaction between the system and users with JSP/Servlet technology, and a new technology of XML, Scalable Vector Graphics (SVG) , is also used to realize the marine data visible. Finally, EJB component technology is used to implement complicated commercial logic of application layer. The perfect combination of J2EE and XML provides the system with good cross-platform ability, portability, expansibility, safety and flexibility. It should be pointed out that the UML-based Rational Rose, one of the popular modeling tools in the world, is applied in the process of designing and implementing of this system. The thesis illustrates detailedly the designing and implementing process and the key technology. Finally, the rationality of the system framework presented in the thesis and the validity of XML in the marine field are verified by deploying and running the integration system.