java SAX 解析 - 获取文本节点的有效方法

SAX parsing - efficient way to get text nodes

提问by Eran Medan

Given this XML snippet

鉴于此 XML 片段

<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>

In SAX, it is easy to get attribute values:

在 SAX 中，很容易获取属性值：

@Override
public void startElement (String uri, String localName,
              String qName, Attributes attributes) throws SAXException{
    if(qName.equals("book")){
        String bookId = attributes.getValue("id");
        ...
    }
}

But to get the value of a text node, e.g. the value of the <author>tag, it is quite hard...

但是要获得一个文本节点的值，例如<author>标签的值，是相当困难的……

private StringBuffer curCharValue = new StringBuffer(1024);

@Override
public void startElement (String uri, String localName,
              String qName, Attributes attributes) throws SAXException {
    if(qName.equals("author")){
        curCharValue.clear();
    }
}

@Override
public void characters (char ch[], int start, int length) throws SAXException
{
     //already synchronized
    curCharValue.append(char, start, length);
}

@Override
public void endElement (String uri, String localName, String qName)
throws SAXException
{
    if(qName.equals("author")){
        String author = curCharValue.toString();
    }
}

1. I'm not sure the above sample is even working, what do you think of this approach?
2. Is there a better way? (to get the text node's value)

1. 我不确定上面的示例是否有效，您如何看待这种方法？
2. 有没有更好的办法？（获取文本节点的值）

回答by ewernli

That's the usual way to do it with SAX.

这是使用 SAX 执行此操作的常用方法。

Just beware that characters()may be called more than once per tag. See this questionfor more info. Here is a complete example.

请注意，characters()每个标签可能会被多次调用。有关更多信息，请参阅此问题。这是一个完整的例子。

Otherwise you could give a try to StAX.

否则你可以试试StAX。

回答by Venkat

public void startElement(String strNamespaceURI, String strLocalName,
      String strQName, Attributes al) throws SAXException {
       if(strLocalName.equalsIgnoreCase("HIT"))
       {
            String output1 = al.getValue("NAME");
          //this will work but how can we parse if NAME="abc" only     ?
       }

   }