java读取xml文件（Dom,Dom4j）

Dear 丶 2021-12-18 06:34 366阅读 0赞

### 1.Dom解析XML ###

package com.fjh.xml;
    
    import java.io.IOException;
    
    import javax.xml.parsers.DocumentBuilder;
    import javax.xml.parsers.DocumentBuilderFactory;
    import javax.xml.parsers.ParserConfigurationException;
    
    import org.w3c.dom.Document;
    import org.w3c.dom.Node;
    import org.w3c.dom.NodeList;
    import org.xml.sax.SAXException;
    
    public class DomParseXml { 
    
    	public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException { 
    		//1、获取解析工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//2、解析器
    		DocumentBuilder builder = factory.newDocumentBuilder(); //alt shift l
    		//3、获取文档对象
    		Document document = builder.parse("product.xml");
    		//测试
    		System.out.println(document.getElementsByTagName("products"));
    		
    		//获取products 节点
    		Node products = document.getElementsByTagName("products").item(0);
    		//获取products节点中所有的子节点
    		NodeList childNodes = products.getChildNodes();
    		//集合大小
    		System.out.println(childNodes.getLength());//5个子节点 包含元素节点和非元素节点（空白节点）
    		for(int index = 0; index < childNodes.getLength(); index ++) { 
    			//获取每一个子节点
    			Node node = childNodes.item(index);
    			//System.out.println( "节点的名称 "+ node.getNodeName());
    			//System.out.println( "节点的类型 "+ node.getNodeType());
    			//System.out.println( "节点的值 "+ node.getNodeValue());
    			if(node.getNodeType() == Node.ELEMENT_NODE) { 
    				//获取属性的值 获取名称为num的属性节点
    				Node namedItem = node.getAttributes().getNamedItem("num");
    				//属性的值
    				String nodeValue = namedItem.getNodeValue();
    				System.out.println(nodeValue);
    				//获取子节点
    				NodeList childNodes2 = node.getChildNodes();
    				for(int i = 0; i < childNodes2.getLength(); i ++) { 
    					Node item = childNodes2.item(i);
    					System.out.println( "节点的名称 "+ item.getNodeName());
    					System.out.println( "节点的类型 "+ item.getNodeType());
    					System.out.println( "节点的值 "+ item.getTextContent());
    				}
    			}
    		}
    		
    	}
    
    }

### 2.Dom4j ###

*  需要下载第三方jar包（Dom4j.jar）

package com.fjh.xml;
    
    import java.io.File;
    import java.util.Iterator;
    
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.Element;
    import org.dom4j.io.SAXReader;
    
    public class Dom4jParseXml { 
    
    	
    	public static void parse(String fileName) throws DocumentException { 
    		
    		
    		//解析器
    		SAXReader reader = new SAXReader();
    		// 获取了文档对象
    		Document document = reader.read(new File(fileName));
    		//<products>
    		Element rootElement = document.getRootElement();
    		System.out.println(rootElement.getName());
    		//迭代子节点
    		for(Iterator<Element> it = rootElement.elementIterator(); it.hasNext();) { 
    			Element product = it.next();
    			//获取属性的值
    			System.out.println("获取属性的值" + product.attributeValue("num"));
    			
    			for(Iterator<Element> it2 = product.elementIterator(); it2.hasNext();) { 
    				Element item = it2.next();
    				//获取属性的值
    				System.out.println("获取节点的名称：" + item.getName() + " 节点的值:" + item.getStringValue());
    			}
    		}
    		
    	}
    	
    	
    	
    	
    	
    	
    	public static void main(String[] args) throws DocumentException { 
    		
    		parse("product.xml");
    	}
    
    }