DOM-XML(解析与创建)

/**
 * 读取(解析)xml文件
 * @author Administrator
 *
 */
public class DOMRead {
   public static void main(String[] args) throws Exception{
      File file=new File("e:\contact.xml");
      InputStream in=new FileInputStream(file);
      //创建DocuemntBuilderFactory实例化对象
      DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
      //通过DocumentBuilderFactory实例化对象来创建DocumentBuilder对象
      DocumentBuilder db=dbf.newDocumentBuilder();
      //通过DocumentBuilder实例化对象 解析方法 来获取Document对象
      Document document=db.parse(in);
      
      //通过document对象来获取指定tagName的所有标签元素
      NodeList memberList = document.getElementsByTagName("member");
      for(int i=0;i<memberList.getLength();i++){
          //获取指定索引的标签元素
         Element ele =(Element) memberList.item(i); 
         //获取标签元素的属性
         String id = ele.getAttribute("id");
         String name = ele.getElementsByTagName("name").item(0).getFirstChild().getNodeValue();
         String phone = ele.getElementsByTagName("phone").item(0).getFirstChild().getNodeValue();
         System.out.println("id="+id+",name="+name+",phone="+phone);
      }  
   }
}


/**
 * 输出(创建)xml文件
 * @author Administrator
 *
 */
public class DOMWrit {
   public static void main(String[] args) throws Exception {
      File outFile=new File("e:"+File.separator+"book.xml");
    
      DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
      DocumentBuilder db=dbf.newDocumentBuilder();
      //通过DocumentBuilder实例化对象 创建方式 来获取Document对象
      Document document=db.newDocument();
      
      //创建根节点books
      Element booksElement=document.createElement("books");
      String[] title=new String[]{"三国演义","红楼梦","水浒传"};
      Double[] price=new Double[]{99.9,88.8,77.7};
      
      for(int i=0;i<title.length;i++){
          //创建book节点
          Element bookElt=document.createElement("book");
          //创建title、price节点
          Element titleElt=document.createElement("title");
          Element priceElt=document.createElement("price");
          //设置title节点的内容,需要创建文本节点
          titleElt.appendChild(document.createTextNode(title[i]));
          //设置price节点的内容,需要创建文本节点
          priceElt.appendChild(document.createTextNode(String.valueOf(price[i])));
          
          //将title、price节点添加到book节点中
          bookElt.appendChild(titleElt);
          bookElt.appendChild(priceElt);
          
          //将book节点添加到books根节点中
          booksElement.appendChild(bookElt);
      }
      //遗忘的步骤
      //将根节点设置到Document之中
      document.appendChild(booksElement);
     
      //将DOM树转换为xml进行输出
      TransformerFactory transformerfactory=TransformerFactory.newInstance();
      Transformer transformer=transformerfactory.newTransformer();
      
      //设置输出的元素
      Source xmlSource=new DOMSource(document);
      
      Result outputTarget=new StreamResult(outFile);
      
      transformer.setOutputProperty(OutputKeys.ENCODING,"UTF-8");
      //输出
      transformer.transform(xmlSource, outputTarget);
      
   }
}