如何用Java和SAX解析我的简单XML文件？

Question

我想解析下面的文件。我想打印每位乘客的身份和姓名。你能给我解析它的代码吗？

<?xml version="1.0" encoding="utf-8"?> 
<root xmlns:android="www.google.com"> 

<passenger id = "001"> 
<name>Tom Cruise</name> 
</passenger> 

<passenger id = "002"> 
<name>Tom Hanks</name> 
</passenger> 

</root> 

UPDATE 这是我试过。码，问题等这里所说的 - Error in output of a simple SAX parser

Answer 1

这里是一个工作示例开始，但我建议你使用StAX的相反，你会看到，SAX是不是很方便

import java.io.File; 
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 SAX2 { 

    public static void main(String[] args) throws Exception { 
     SAXParser parser = SAXParserFactory.newInstance().newSAXParser(); 
     parser.parse(new File("test.xml"), new DefaultHandler() { 

      @Override 
      public void startElement(String uri, String localName, 
        String qName, Attributes atts) throws SAXException { 
       if (qName.equals("passenger")) { 
        System.out.println("id = " + atts.getValue(0)); 
       } 
      } 

      @Override 
      public void endElement(String uri, String localName, String qName) 
        throws SAXException { 
      } 

      @Override 
      public void characters(char[] ch, int start, int length) 
        throws SAXException { 
       String text = new String(ch, start, length); 
       if (!text.trim().isEmpty()) { 
        System.out.println("name " + text); 
       } 
      } 
     }); 
    } 
} 

输出

id = 001 
name Tom Cruise 
id = 002 
name Tom Hanks 

Answer 2

1. 创建DocumentBuilderFactory。
2. 从工厂获得DocumentBuilder。
3. 使用建造者的parse()方法之一创建Document。
4. 一旦你有Document，你可以通过Document的getElementsByTagName()方法得到乘客Element。

我相信你能解决余下的问题。

Answer 3

SAXParserFactory factory = SAXParserFactory.newInstance(); 
try { 

    InputStream xmlInput = new FileInputStream("theFile.xml"); 
    SAXParser  saxParser = factory.newSAXParser(); 

    DefaultHandler handler = new SaxHandler(); 
    saxParser.parse(xmlInput, handler); 

} catch (Throwable err) { 
    err.printStackTrace(); 
} 

Answer 4

String str = "<?xml version=\"1.0\" encoding=\"utf-8\"?> " + 
         "<root xmlns:android=\"www.google.com\">" + 
          "<passenger id = \"001\">" + 
           "<name>Tom Cruise</name>" + 
          "</passenger>" + 
          "<passenger id = \"002\">" + 
           "<name>Tom Hanks</name>" + 
          "</passenger>" + 
         "</root>"; 
      DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
      DocumentBuilder db = dbf.newDocumentBuilder(); 
      InputSource is = new InputSource(new StringReader(str)); 

      final Document document = db.parse(is); 

      System.out.println("node Name " + document.getChildNodes().item(0).getChildNodes().item(1).getNodeName());