XMLEventReader的基于Filter的过滤方式解析xml文件

XMLEventReader的基于Filter的过滤方式解析xml文件

public static void test05() {
  XMLInputFactory factory = XMLInputFactory.newInstance();
  InputStream is = null;
  try {
   is = TestStax.class.getClassLoader().getResourceAsStream("books.xml");
   //基于Filter的过滤方式，可以有效的过滤掉不用进行操作的节点，效率会高一些
   XMLEventReader reader = factory.createFilteredReader(factory.createXMLEventReader(is),
     new EventFilter() {
      @Override
      public boolean accept(XMLEvent event) {
       //返回true表示会显示，返回false表示不显示
       if(event.isStartElement()) {
        String name = event.asStartElement().getName().toString();
        if(name.equals("title")||name.equals("price"))
         return true;
       }
       return false;
      }
     });
   int num = 0;
   while(reader.hasNext()) {
    //通过XMLEvent来获取是否是某种节点类型
    XMLEvent event = reader.nextEvent();
    if(event.isStartElement()) {
     //通过event.asxxx转换节点
     String name = event.asStartElement().getName().toString();
     if(name.equals("title")) {
      System.out.print(reader.getElementText()+":");
     }
     if(name.equals("price")) {
      System.out.print(reader.getElementText()+"\n");
     }
    }
    num++;
   }
   System.out.println(num);
  } catch (XMLStreamException e) {
   e.printStackTrace();
  } finally {
   try {
    if(is!=null) is.close();
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
 }