Apache Commons Digest Framework Introduction and Use Tutorial

Apache Commons Digester is a Java framework for extracting data from XML files.It is based on event -driven SAX parser and can map XML data to the Java object according to a set of rules.This framework provides a simplified XML analysis function, so that developers can more easily extract data from XML. Below are some common scenes and examples of Apache Commons Digest: 1. Create a DIGESTER object: Digester digester = new Digester(); 2. Setting rules: // Set matching rules to match the XML element you want to extract digester.addRule("root/element", new MyClassRule()); // Set the processing logic of the corresponding rules digester.addCallMethod("root/element", "setElementValue", 1); digester.addCallParam("root/element", 0); 3. Implement the logic of regular processing: public class MyClassRule extends Rule { public void begin(Attributes attributes) throws Exception { // The logic executed when starting matching the specified element } public void end(String namespace, String name) throws Exception { // The logic executed when ending the specified element } } 4. Start parsing XML file: MyClass obj = (MyClass) digester.parse(xmlFile); Through the above steps, Apache Commons Digerster will extract the data from the XML file and map it into the Java object according to the setting rules. This is a simple example.In actual use, more rules and processing logic can be set according to specific needs.In addition, Apache Commons Digest also provides other functions, such as error processing, XML naming space support, etc. In order to better understand the usage and functions of the DIGESTER framework, please refer to the official documentation and sample program.