Data analysis and processing method based on XMLPARSERAPIS in Java library
The data analysis and processing method based on the XML analysis API in the Java class library
Overview:
In Java programming, data in XML format often needs to be processed and parsed.The Java class library provides a variety of data analysis and processing methods based on XML -based analysis API. This article will introduce some commonly used methods and provide corresponding Java code examples.
1. DOM analysis:
DOM (Document Object Model) is an XML parsing method based on tree -shaped structure.It loads the entire XML document to the memory and uses a tree structure to represent the XML element and its attributes.The following is an example code using DOM parsing XML data:
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
public class DOMParserExample {
public static void main(String[] args) {
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse("data.xml");
// Get the root element
Element root = document.getDocumentElement();
// Severe elements
NodeList nodeList = root.getElementsByTagName("item");
for (int i = 0; i < nodeList.getLength(); i++) {
Element item = (Element) nodeList.item(i);
// Get the attribute value of the element
String id = item.getAttribute("id");
String name = item.getElementsByTagName("name").item(0).getTextContent();
// Data processing
// ...
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
2. SAX analysis:
SAX (Simple API for XML) is an XML parsing method based on event -driven.It traverses the XML tree structure and processs data through the recovery function processing the event in the XML document.The following is an example code that uses SAX to resolve XML data:
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
public class SAXParserExample {
public static void main(String[] args) {
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();
// Create an event processor
DefaultHandler handler = new DefaultHandler() {
boolean isName = false;
// Start the element event
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
if (qName.equals("name")) {
isName = true;
}
}
// End the element event
public void endElement(String uri, String localName, String qName) throws SAXException {
if (qName.equals("name")) {
isName = false;
}
}
// character data event
public void characters(char[] ch, int start, int length) throws SAXException {
if (isName) {
String name = new String(ch, start, length);
// Data processing
// ...
}
}
};
// Analyze XML document
parser.parse("data.xml", handler);
} catch (Exception e) {
e.printStackTrace();
}
}
}
3. JAXB Analysis:
JAXB (Java Architecture for XML Binding) is a parsing method that binds XML data to the Java object.It can generate the Java class according to the description of the XML and provide the function of converting XML data into the Java object.The following is an example code using JAXB to resolve XML data:
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import java.io.File;
public class JAXBParserExample {
public static void main(String[] args) {
try {
JAXBContext context = JAXBContext.newInstance(Data.class);
Unmarshaller unmarshaller = context.createUnmarshaller();
Data data = (Data) unmarshaller.unmarshal(new File("data.xml"));
// Get the data after the analytical
// ...
} catch (JAXBException e) {
e.printStackTrace();
}
}
}
// Data class
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name="data")
public class Data {
private String name;
public String getName() {
return name;
}
@XmlElement(name="name")
public void setName(String name) {
this.name = name;
}
}
Summarize:
This article introduces data analysis and processing methods based on XML -based analysis API in the Java library.DOM analysis loads the entire XML document to the memory and uses a tree structure to represent the XML element; SAX analysis processs the event in the XML document through the callback function, and analyze it one by one; the JAXB analysis binds the XML data to the Java object, which provides conveniently provides convenientData conversion function.According to specific needs, selecting suitable analysis methods can process XML data more efficiently.
