Handling Lexical Events-优快云博客

本文介绍了如何使用SAX解析器中的LexicalHandler来处理文档中的词汇信息，包括注释、CDATA段、实体及DTD等元素。通过实现特定接口的方法，应用程序可以接收这些信息并进行相应的处理。

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How the LexicalHandler Works

To be informed when the SAX parser sees lexical information, you configure the XmlReader that underlies the parser with a LexicalHandler. The LexicalHandler interface defines these event-handling methods:

comment(String comment)

Passes comments to the application

startCDATA(), endCDATA()

Tells when a CDATA section is starting and ending, which tells your application what kind of characters to expect the next time characters() is called

startEntity(String name), endEntity(String name)

Gives the name of a parsed entity

startDTD(String name, String publicId, String systemId), endDTD()

Tells when a DTD is being processed, and identifies it

下面是具体的函数体

public void comment(char[] ch, int start, int length)
throws SAXException
{
}

public void startCDATA()
throws SAXException
{
}

pubic void endCDATA()
throws SAXException
{
}

public void startEntity(String name)
throws SAXException
{
}

public void endEntity(String name)
throws SAXException
{
}

public void startDTD(
  String name, String publicId, String systemId)
throws SAXException
{
}

public void endDTD()
throws SAXException
{
}

当startEntity(String name)和endEntity(String name)遇到DTD声明中部分，打印出来的内容，是StartEntity:[dtd]，对于多个entity声明也只生成这一个打印。不显示具体的entity定义的变量的名字，只显示[dtd].