A prototype for spatial information services based on J2EE

J2EE (Java 2 Platform , Enterprise Edition) is a kind of architecture that simplifies the development ,design and management of multilevel enterprise solution. The spatial middlewares based on J2EE can easily resolve the problems which the traditional Geographic Information Systems (GIS) now have to face with, such as transplantability, stability, easy maintainability and many more. This paper first introduces some conceptions and principles about J2EE, spatial middleware, then proposes a concrete J2EE-based solution of spatial middleware, namely SISP AS, which develops on JBoss(an open sources application server of J2EE) and uses the SISP spatial database. SISP AS follows Open GIS specifications, and implements a subset of OGC services, it improves interoperability and commonality by using XML/GML for communication and data transmission, resolves the transmission efficiency problem of large spatial data by using raster pyramid and vector pyramid. Finally, the related work will be presented. Notably, the experiments on this prototype system can proves that it is available to manage, distribute and share large scale spatial data by using SISP AS.     

J2EE平台WebGIS设计技术探讨

针对传统WebGIs设计方法的局限性，利用Java平台无关性的优点，为拓展GIS在电子政务中的应用，提出了基于J2EE平台的Browser／server模式的分布式解决方案，并以一个城市电子地图为例，着重探讨了J2EE平台上采用中间件（MapXtrerne）设计和架构应用于电子政务的WebGIS的思想，主要包括客户端的选择、功能考虑以及服务器端的结构设计等，并据此提供了一个原型．该原型的建立及其设计的思想方法对于其他更为复杂的WebGIS的开发具有借鉴意义．     

基于J2EE技术的在线课件编著系统的设计

基于J2EE技术平台,设计了一个远程教学在线课件编著系统。该系统由客户层、中间层、数据库层三个层次组成,每一层的设计都充分考虑到课件知识点结构动态变化的特点和分布式处理环境的要求。着重讨论利用J2EE技术,解决了在传统的远程教学系统中,教师要先在本地编写好课件然后上传到服务器,学生通过下栽学习的弊端,真正做到“教师在线编辑,学生在线学习”。     

A solution for digital image management in spatial databases

Digital Orthographic Map (DOM) can be used in various applications because it contains both image features and terrain information. Spatial database management systems aim at the effective and efficient management of data related to a space,engineering design and so on. Thereby spatial database provides an efficient solution for managing DOM. According to large amounts of the DOM data in storage, a data compression based on wavelet is introduced into the storage. Another strategy to solve this problem is to decompose the raw image into tiles and store the tiles individually as separate tuples. The metadata of DOM can be used to organize and manage spatial information,especially for spatial data sharing and fast locating. A tool for browsing, zooming and querying the DOM data is also designed. We implemented these ideas in SISP (Spatial Information Sharing System) and applied the subsystem into the DOM management of Beijing City, which is an component of the Beijing Spatial Information Infrastructure.     

A solution for digital image management in spatial databases

Digital Orthographic Map (DOM) can be used in various applications because it contains both image features and terrain information. Spatial database management systems aim at the effective and efficient management of data related to a space, engineering design and so on. Thereby spatial database provides an efficient solution for managing DOM. According to large amounts of the DOM data in storage, a data compression based on wavelet is introduced into the storage. Another stratcgy to solve this problem is to decompose the raw image into tiles and store the tiles individually as separate tuples. The metadata of DOM can be used to organize and manage spatial information, especially for spatial data sharing and fast locating. A tool for browsing, zooming and querying the DOM data is also designed. We implemented these ideas in SISP (Spatial Information Sharing System) and applied the subsystem into the DOM management of Beiiing City, which is an component of the Beijing Spatial Information Infrastructure.     

广西巩固退耕还林成果专项建设管理信息系统设计与实现

利用Weblogic中间件,Oracle10g数据库,基于Structs2+Spring+Hibernate设计模式的J2EE技术,设计并实现广西巩固退耕还林成果专项建设管理信息系统。系统主要实现广西巩固退耕还林成果专项建设六大专项的统一化、信息化管理,能够成为巩固退耕还林成果专项建设管理规范化、科学化的有效辅助工具。     

基于J2EE的大型新闻图片图表管理系统

本文主要以J2EE技术为背景,介绍了J2EE的基本思想及体系结构,讨论了如何将该体系应用于某大型新闻社图片图表综合系统的更新改造当中;同时,结合该系统的需求,论述了以中间件逻辑层为核心的J2EE三层体系结构在系统设计中的体现及运用,并对系统的实现作了进一步的介绍.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

基于ArcSDE和SQL Server2000洪水灾害信息数据库的设计研究

空间数据库是目前地理信息系统应用的重要支撑部分.洪水灾害数据存在数据量大、种类多、保密强等特点,所以洪水灾害信息数据库的设计也不完全等同于其他空间数据库的设计.结合实际工作,对洪水灾害信息数据库建设中ArcSDE和SQL Server2000的配置,以及用户安全管理、数据入库参数（分块大小、金字塔技术、压缩方式）等技术方法进行了探讨.     

基于J2EE高速公路网络地理信息系统平台研究

探讨了基于J2EE（Java 2 Enterprise Edition）的高速公路网络地理信息系统（webGIS）平台架构及其关键技术，包括高速公路空间数据组织和设计。WebGIS中间件技术，数据库连接池技术，高速公路WebGiS的动态分段技术等．建立了高速公路WebGIS地理信息平台，以惠河高速公路管理为例，介绍了地理信息平台的功能和应用，验证了文中的各种技术与方法．     

基于JAVA中间件的校园网格应用研究

为了解决校园网网格应用中的软件集成问题,提出了通过基于XML的Java中间件来实现校园网内部各部门间数据的转换与匹配。首先通过Java中间件对校园内旧有异构数据库中的数据进行XML文档化转换,然后给出一套基于开放源代码的MuleESB的J2EE架构以组建SOA的软件集成系统实用方法来最终实现校园网格的应用。文章最后通过一个应用实例对这一架构下的关键技术进行研究,并使用JMeter进行了性能测试,验证了本集成系统的有效性和优越性。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations: retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value, too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels. Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

GIS系统中多维海洋数据可视化研究

提出设计混合型GIS系统解决方案,可以在同一个视图窗体中分别从海洋表面、海洋内部、海底表面和海底深部四个空间层次来可视化显示2D,2.5D和3D矢量栅格海洋数据.Geodatabase地理数据模型有助于统一组织、管理、可视化表达多维海洋数据,是构建海洋地理数据库的有效方式.基于ArcEngine软件开发设计混合型GIS,表明混合型GIS能够真实地表达数据几何位置,不仅能够表达空间对象之间的平面关系,而且能描述和表达它们之间的垂向关系,保证用户能够对多维海洋空间对象进行空间操作.     

Web下的文档管理系统研究及应用

针对现有C／S文档管理系统的缺点和文档管理的实际需求，提出了以Web和J2EE技术为集成框架，实现分布式文档管理系统功能；介绍了基于Web的文档管理系统的设计方法及其体系结构，以面向对象的思想，分析了利用J2EE中间件技术和Web的三层B/S计算模式实现文档管理的关键技术并给出具体的实现方法；最后给出了系统的实际应用案例．     

基于J2EE平台的EAI体系结构的研究

分析和研究了在EAI中使用的三种集成模式界面集成、数据集成和业务功能集成,以及两种集成架构点对点集成和基于中间件的集成.结合实例提出了基于J2EE平台的EAI结构模型.其EAI结构模型对一般企业都有借鉴作用.     

Web下的文档管理系统研究及应用

针对现有C/S文档管理系统的缺点和文档管理的实际需求,提出了以Web和J2EE技术为集成框架,实现分布式文档管理系统功能;介绍了基于Web的文档管理系统的设计方法及其体系结构,以面向对象的思想,分析了利用J2EE中间件技术和Web的三层B/S计算模式实现文档管理的关键技术并给出具体的实现方法;最后给出了系统的实际应用案例.     

基于J2EE构造船舶集成平台管理系统

以CAN/Ethernet网关已实现将底层采集到的船舶设备实时数据存入到上层数据库为基础,研究利用J2EE技术对这些已共享的数据进行进一步分析处理,给出了基于J2EE平台体系结构的船舶集成平台管理系统的解决方案。     

基于J2EE构造船舶集成平台管理系统

以CAN/Ethernet网关已实现将底层采集到的船舶设备实时数据存入到上层数据库为基础,研究利用J2EE技术对这些已共享的数据进行进一步分析处理,给出了基于J2EE平台体系结构的船舶集成平台管理系统的解决方案.     

基于J2EE的WebGIS的模型研究

网络地理信息系统(WebGIS)是当前GIS技术研究热点,实现WebGIS系统的方法有许多种,这里在比较多种WEBGIS开发方法的同时提出了基于J2EE体系结构的WebGIS开发模型,并且列举了该模型的优势.     

基于J2EE WebGIS的一种空间数据管理方法

在阐述基于J2EE的WebGIS概念、体系结构以及Oracle9i spatial的原理、新特性的基础上，结合具体实例给出了一种用oracle9i spatial臬解决J2EEWebGIS下的空间数据库实现技术。