Java解析XML(一) 使用DOM读取XML文件

清疚 2022-06-07 04:44 215阅读 0赞

## DOM ##

DOM 是最容易使用的java XML解析器。它可以解析一个完整的XML文档并将其加载到内存中，然后用对象对其进行建模，以实现简单的node遍历。DMO是将XML直接加载到内存中进行处理的，所以不建议解析较大的XML文件。

## 读取XML文件 ##

### 目标文件xmlDemo.xml ###

<?xml version="1.0" encoding="UTF-8"?>
    <note auth="Byron.y.y">
      <to>Tove</to>
      <from>Jani</from>
      <heading>Reminder</heading>
      <body>Don't forget me this weekend!</body>
    </note>

### java代码使用dom4j解析XML文件 ###

package byron4j.xml;
    
    import java.io.File;
    
    import javax.xml.parsers.DocumentBuilder;
    import javax.xml.parsers.DocumentBuilderFactory;
    
    import org.w3c.dom.Document;
    import org.w3c.dom.Element;
    import org.w3c.dom.Node;
    import org.w3c.dom.NodeList;
    
    public class DomDemo1 { 
    	public static void main(String[] args) throws Exception{ 
    		
    		String classPath = DomDemo1.class.getClass()
    					.getResource("/").getPath();
    		
    		File file = new File(classPath);
    		String fth = file.getParent();
    		File fFile = new File(fth);
    		String xmlPath = fFile.getParent() + "\\src\\xmlDemo.xml";
    		
    		
    		File fXmlFile  = new File(xmlPath);
    		
    		DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    		DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
    		Document doc = dBuilder.parse(fXmlFile);
    
    		doc.getDocumentElement().normalize();
    
    		System.out.println("Root element :" + doc.getDocumentElement().getNodeName());
    
    		NodeList nList = doc.getElementsByTagName("note");
    
    		System.out.println("----------------------------");
    
    		for (int temp = 0; temp < nList.getLength(); temp++) { 
    
    			Node nNode = nList.item(temp);
    
    			System.out.println("\nCurrent Element :" + nNode.getNodeName());
    
    			if (nNode.getNodeType() == Node.ELEMENT_NODE) { 
    
    				Element eElement = (Element) nNode;
    				System.out.println("author==> : " +eElement.getAttribute("auth"));
    				System.out.println("1==> : " + eElement.getElementsByTagName("to").item(0).getTextContent());
    				System.out.println("2==> : " + eElement.getElementsByTagName("from").item(0).getTextContent());
    				System.out.println("3==> : " + eElement.getElementsByTagName("heading").item(0).getTextContent());
    				System.out.println("4==> : " + eElement.getElementsByTagName("body").item(0).getTextContent());
    				
    
    			}
    		}
    	}
    }

运行结果：

Root element :note
    ----------------------------
    
    Current Element :note
    author==> : Byron.y.y
    1==> : Tove
    2==> : Jani
    3==> : Reminder
    4==> : Don't forget me this weekend!