From: Ian S. <Ian...@ar...> - 2003-03-26 00:20:34
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Hi, On IRC I said I'd put together a silly demo showing how a heirarchical data structure could be visited and written to XML. This came out far more elegant than planned. The source (and classes) are here: http://oms.ars.usda.gov/~en/visitor-example.zip There are two classes representing data. Feature and Attribute. A Feature is an Attribute. A Feature has Attributes. Thus we set up the hierarchy. Attribute follows the visitor pattern with the interface AttributeVisitor. WalkingVisitor implements AttributeVisitor and ensures a depth first traversal. WalkingVisitor delegates the traversal to another interface WalkingVisitor.Walker. FeatureReader is an XMLReader with a one argument constructor containing a Feature. It contains a method called transform(OutputStream out) which will produce XML to the given OutputStream. To execute it, use TestDriver. Direct questions hither. Ian |