| 摘要 |
A parsing technique suitable for use in electronic commerce that avoids the disadvantages of known monolithic parsers. The parsing system generates code specific to each input document and data stream type, which may then be updated as needed to handle document-specific idiosyncrasies without requiring modifications to the core parser code. As a user (10) defines parsing rules for extracting data from a representative sample document (15), a visual trainer (16) automatically generates code in the background, referred to as a filer (17), that is specific to that document and that embodies the rules for extracting data from that particular document. The generated code may be modified manually (18) as needed to account for any idiosyncratic conditions associated with the document. Each representative document has associated with it its own filer. A parsing engine (20, 21) comprises a collection of such individual filers appropriate for the types of documents that arise in any given organization. A mapping or other association is maintained between representative document types and their filers. In regular operation, a user selects a data set to be extracted from certain documents. When the parsing engine receives a document in an input data stream, the associated filer is loaded and parses that document for the selected data set. Then another filer is loaded in response to another input document, and so on. The filers may be especially efficiently generated using an object-oriented approach and then dynamically instantiated at run time as may be conveniently achieved, for example, in the Java programming language.
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