使用SAX解析常见的XML元素

以下是我对类似问题的答案（使用sax跳过节点）。它演示了如何在XMLReader上交换内容处理程序。

在此示例中，ContentHandler中交换的内容只是忽略所有事件，直到它放弃控制为止，但您可以轻松地调整该概念。

您可以执行以下操作：

import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.XMLReader;public class Demo {    public static void main(String[] args) throws Exception {         SAXParserFactory spf = SAXParserFactory.newInstance();         SAXParser sp = spf.newSAXParser();         XMLReader xr = sp.getXMLReader();         xr.setContentHandler(new MyContentHandler(xr));         xr.parse("input.xml");     } }

MyContentHandler

此类负责处理您的XML文档。击中要忽略的节点时，可以在IgnoringContentHandler中进行交换，这将吞噬该节点的所有事件。

import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.XMLReader;public class MyContentHandler implements ContentHandler {    private XMLReader xmlReader;    public MyContentHandler(XMLReader xmlReader) {         this.xmlReader = xmlReader;     }    public void setdocumentLocator(Locator locator) {     }    public void startdocument() throws SAXException {     }    public void enddocument() throws SAXException {     }    public void startPrefixMapping(String prefix, String uri)  throws SAXException {     }    public void endPrefixMapping(String prefix) throws SAXException {     }    public void startElement(String uri, String localName, String qName,  Attributes atts) throws SAXException {         if("sodium".equals(qName)) {  xmlReader.setContentHandler(new IgnoringContentHandler(xmlReader, this));         } else {  System.out.println("START " + qName);         }     }    public void endElement(String uri, String localName, String qName)  throws SAXException {         System.out.println("END " + qName);     }    public void characters(char[] ch, int start, int length)  throws SAXException {         System.out.println(new String(ch, start, length));     }    public void ignorableWhitespace(char[] ch, int start, int length)  throws SAXException {     }    public void processingInstruction(String target, String data)  throws SAXException {     }    public void skippedEntity(String name) throws SAXException {     }}

忽略ContentHandler

当IgnoringContentHandler完成吞咽事件后，它将控制权传递回您的主ContentHandler。

import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.XMLReader;public class IgnoringContentHandler implements ContentHandler {    private int depth = 1;     private XMLReader xmlReader;     private ContentHandler contentHandler;    public IgnoringContentHandler(XMLReader xmlReader, ContentHandler contentHandler) {         this.contentHandler = contentHandler;         this.xmlReader = xmlReader;     }    public void setdocumentLocator(Locator locator) {     }    public void startdocument() throws SAXException {     }    public void enddocument() throws SAXException {     }    public void startPrefixMapping(String prefix, String uri)  throws SAXException {     }    public void endPrefixMapping(String prefix) throws SAXException {     }    public void startElement(String uri, String localName, String qName,  Attributes atts) throws SAXException {         depth++;     }    public void endElement(String uri, String localName, String qName)  throws SAXException {         depth--;         if(0 == depth) { xmlReader.setContentHandler(contentHandler);         }     }    public void characters(char[] ch, int start, int length)  throws SAXException {     }    public void ignorableWhitespace(char[] ch, int start, int length)  throws SAXException {     }    public void processingInstruction(String target, String data)  throws SAXException {     }    public void skippedEntity(String name) throws SAXException {     }}