Commons Digester framework tutorial commonly used in the Java class library

Commons Digester is a commonly used Java class library for analysis and mapping XML to Java objects.It provides a simple and powerful way to handle the XML document, enabling developers to extract data from XML more easily and convert it to Java objects. Here are some basic concepts and usage examples of the COMMONS DIGESTER framework: 1. XML rule definition: Before using Commons Digest, a series of XML rules need to be defined to tell Digerster how to analyze XML and map it to the Java object.These rules are usually defined by DTD or XSD documents. 2. Create a DIGESTER instance: First of all, we need to create a DIGESTER instance and perform some basic configurations, such as setting whether to open the naming space support and setting rule verification. Digester digester = new Digester(); digester.setNamespaceAware(true); digester.setValidating(true); 3. Add XML rules: Next, we can use the Digerster API method to add XML rules.For example, using the `addcallMethod` method to mappore a specific XML element with the Java object method. digester.addCallMethod("root/element", "methodName", 1); digester.addCallParam("root/element", 0); 4. Register the Java object: Before parsing XML as the Java object, you need to register the Java object into the Digetter and specify which XML element starts to map. digester.addObjectCreate("root", Root.class); digester.addSetNext("root", "setRoot"); 5. Perform analysis: After completing the above configuration, we can use the `PARSE` Method of the DIGESTER to perform the parsing operation. Root root = (Root) digester.parse(inputStream); The above is an example of the basic usage of the Commons Digester framework.With Commons Digest, developers can easily process XML data and convert it to Java objects to improve development efficiency. Please note: This article is only an example. In actual use, you need to configure and operate more detailed configuration and operation according to specific needs and documents.