jaxp解析xml

迈不过友情╰ 2022-08-12 12:00 192阅读 0赞

有一个xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?><书架>
    	<书>
    		<书名 name="xxxx">java web</书名>
    		<作者>张大</作者>
    		<价格>99</价格>
    	</书>
    	<书>
    		<书名>spring</书名>
    		<作者>呜呜</作者>
    		<价格>55</价格>
    	</书>
    </书架>

读取指定节点的内容

public void read1() throws Exception{
    		//创建工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//得到Dom解析器
    		DocumentBuilder builder = factory.newDocumentBuilder();
    		//得到代表文档的document
    		Document document = builder.parse("src/book.xml");
    		
    		NodeList list = document.getElementsByTagName("书名");
    		Node node = list.item(1);
    		String content = node.getTextContent();
    		System.out.println(content);
    		
    	}

遍历所有标签

public void read2() throws Exception{
    		
    		//创建工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//得到Dom解析器
    		DocumentBuilder builder = factory.newDocumentBuilder();
    		//得到代表文档的document
    		Document document = builder.parse("src/book.xml");
    		
    		Node root = document.getElementsByTagName("书架").item(0);
    		
    		traverse(root);
    		
    	}
    
    	private void traverse(Node node) {
    		
    		if(node instanceof Element){
    			System.out.println(node.getNodeName());
    		}
    		NodeList list = node.getChildNodes();
    		for(int i=0;i<list.getLength();i++){
    			Node child = list.item(i);
    			traverse(child);
    		}
    	}

得到标签属性

public void read3() throws Exception{
    		//创建工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//得到Dom解析器
    		DocumentBuilder builder = factory.newDocumentBuilder();
    		//得到代表文档的document
    		Document document = builder.parse("src/book.xml");
    		
    		Element bookname =  (Element) document.getElementsByTagName("书名").item(0);
    		String value = bookname.getAttribute("name");
    		System.out.println(value);
    	}

在指定位子添加节点，不指定加在最后一个位子

public void add() throws Exception{
    		//创建工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//得到Dom解析器
    		DocumentBuilder builder = factory.newDocumentBuilder();
    		//得到代表文档的document
    		Document document = builder.parse("src/book.xml");
    		
    		//价格上添加评价
    		Element evaluate = document.createElement("评价");
    		evaluate.setTextContent("well");
    		//得到参考节点
    		Element reNode = (Element) document.getElementsByTagName("价格").item(0);
    		//得到父节点
    		Element book =  (Element) document.getElementsByTagName("书").item(0);
    		//父节点中插入
    		book.insertBefore(evaluate, reNode);
    		
    		//更新后的内存写入xml文档
    		TransformerFactory tf_factory =  TransformerFactory.newInstance();
    		Transformer t = tf_factory.newTransformer();
    		t.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));
    	}

删除节点

<span style="white-space:pre">	</span>public void delete() throws Exception{
    		//创建工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//得到Dom解析器
    		DocumentBuilder builder = factory.newDocumentBuilder();
    		//得到代表文档的document
    		Document document = builder.parse("src/book.xml");
    		
    		//得到要删除的节点
    		Element price =  (Element) document.getElementsByTagName("价格").item(0);
    		//得到父节点
    		Element book =  (Element) document.getElementsByTagName("书").item(0);
    		
    		//删
    		book.removeChild(price);
    		//更新后的内存写入xml文档
    		TransformerFactory tf_factory =  TransformerFactory.newInstance();
    		Transformer t = tf_factory.newTransformer();
    		t.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));
    	}

第二种删除方法

public void delete2() throws Exception{
    		//创建工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//得到Dom解析器
    		DocumentBuilder builder = factory.newDocumentBuilder();
    		//得到代表文档的document
    		Document document = builder.parse("src/book.xml");
    		
    		//得到要删除的节点
    		Element e =  (Element) document.getElementsByTagName("价格").item(0);
    		e.getParentNode().removeChild(e);
    	
    		//更新后的内存写入xml文档
    		TransformerFactory tf_factory =  TransformerFactory.newInstance();
    		Transformer t = tf_factory.newTransformer();
    		t.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));
    	}

更新节点

@Test	
    	public void update() throws Exception{
    		//创建工厂
    		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    		//得到Dom解析器
    		DocumentBuilder builder = factory.newDocumentBuilder();
    		//得到代表文档的document
    		Document document = builder.parse("src/book.xml");
    		
    		//得到要更新的节点
    		Element e =  (Element) document.getElementsByTagName("价格").item(0);
    		e.setTextContent("102");
    	
    		//更新后的内存写入xml文档
    		TransformerFactory tf_factory =  TransformerFactory.newInstance();
    		Transformer t = tf_factory.newTransformer();
    		t.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));
    	}