dom4j解析xml文档

爱被打了一巴掌 2022-08-12 16:04 191阅读 0赞

有一个xml文档

<?xml version="1.0" encoding="utf-8"?>
    
    <书架> 
      <书> 
        <书名 name="xxxx">java web</书名>  
        <作者>张大</作者>  
        <价格>102</价格>  
        <评价>well</评价> 
      </书>  
      <书> 
        <书名>spring</书名>  
        <作者>呜呜</作者>  
        <价格>55</价格> 
      </书> 
    </书架>

读取文档的内容（第二本书的书名）

public void read() throws DocumentException{
    		SAXReader reader = new SAXReader();
    	    Document document = reader.read(new File("src/book.xml"));
    	    
    	    Element root = document.getRootElement();
    	    Element book = (Element) root.elements("书").get(1);
    	    String value = book.element("书名").getText();
    	    System.out.println(value);
    	}

读取文档的属性（name中的属性）

public void readAtrr() throws DocumentException{
    		SAXReader reader = new SAXReader();
    	    Document document = reader.read(new File("src/book.xml"));
    	    
    	    Element root = document.getRootElement();
    	    Element book = (Element) root.elements("书").get(0);
    	    String value = book.element("书名").attribute("name").getValue();
    	    System.out.println(value);
    
    	}

在默认位子添加一个评价

public void add() throws Exception{
    		SAXReader reader = new SAXReader();
    	    Document document = reader.read(new File("src/book.xml"));
    	    
    	    Element book = document.getRootElement().element("书");
    	    book.addElement("评价").setText("well");
    	    
    	    //更新到xml，注意乱码问题
    	    XMLWriter writer = new XMLWriter(
    	    		new OutputStreamWriter(new FileOutputStream("src/book.xml"), "utf-8")
    	    );
    	    writer.write( document );  //UTF-8
            writer.close();
    	}

在指定位子添加（价格上）

public void add3() throws Exception{
    		SAXReader reader = new SAXReader();
    	    Document document = reader.read(new File("src/book.xml"));
    	    
    	    Element book = document.getRootElement().element("书");
    	    List list = book.elements();
    	    
    	    //创建要加入的节点
    	    Element evaluation = DocumentHelper.createElement("评价");
    	    evaluation.setText("good,good");
    	    
    	    list.add(2, evaluation);
    	    
    	    //更新到xml，注意乱码问题
    	    OutputFormat format = OutputFormat.createPrettyPrint();
    	    format.setEncoding("utf-8");//和xml文档一致
    	    XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format );
    	    
    	    writer.write( document );  //UTF-8
            writer.close();
    	}

删除一个评价

public void delete() throws Exception{
    		SAXReader reader = new SAXReader();
    	    Document document = reader.read(new File("src/book.xml"));
    	    
    	    List list = document.getRootElement().element("书").elements("评价");
    	    list.remove(0);
    	    
    	    //更新到xml，注意乱码问题
    	    OutputFormat format = OutputFormat.createPrettyPrint();
    	    format.setEncoding("utf-8");//和xml文档一致
    	    XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format );
    	    
    	    writer.write( document );  //UTF-8
            writer.close();
    	}

更改节点

public void update() throws Exception{
    		SAXReader reader = new SAXReader();
    	    Document document = reader.read(new File("src/book.xml"));
    	    
    	    Element book = (Element) document.getRootElement().elements("书").get(1);
    	    book.element("作者").setText("哈哈！");
    	    
    	    OutputFormat format = OutputFormat.createPrettyPrint();
    	    format.setEncoding("utf-8");//和xml文档一致
    	    XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format );
    	    
    	    writer.write( document );  //UTF-8
            writer.close();
    	    
    	}