GML是一种基于XML的标记性语言,但不支持地理数据的可视化显示,通过XSLT语言,将GML转换为W3C制定的矢量图形格式SVG,可以方便与用户的交互和地理数据的可视化显示.传统的XSLT转换处理器采用DOM的解析技术,对大数据量的GML文档处理上有很大的局限性.文中实现了一个支持大数据量GML文档的XSLT转换器GSxslt,采用SAX事件解析技术,同时优化了转换所需要的样式表文件,设计了样式表文件分类优化算法.实验证明GSxslt处理器在转换性能上较传统XSLT处理器有了很大的提高.
GML is a markup language based on XML.But it is not designed to be a web-map publishing format that can be displayed in web browser.With the help of XSLT language,GML files can be transformed to SVG files for deeper interaction with users and better visualization effect.And Traditional XSLT processors usually use DOM skill to parse GML files,which does not play well on large GML files with mass data.This paper provides a method that supports the transformation from large GML to SVG,and we have developed a optimized XSLT processor,GSxslt,based on the method.The algorithm takes SAX parsing skill instead of DOM one.Meanwhile it has optimized XSL files that are needed in the process of transformation.It implements an optimized algorithm,which is designed to classify the XSL file for higher efficiency.Experiments show that GSxslt do have a better performance,compared with the traditional ones.