JAVA SAX 解析器拆分对字符的调用() [英] JAVA SAX parser split calls to characters()

问题描述

我正在做一个项目来解析 XML 中的一些数据.

I am doing a project to parse some data from the XML.

例如，XML 是

<abc>abcdefghijklmno</abc>

我需要解析abcdefghijkmnlp".

I need to parse "abcdefghijkmnlp".

但是当我测试我的解析时，我发现了一个大问题:

But while I test my parse, I discover a big problem:

public class parser{
    private boolean hasABC = false;


        //Constructor HERE
        ......................
        ......................

     @Override
     public void startDocument () throws SAXException{  
     }

     @Override
     public void endDocument () throws SAXException{  
     }

     @Override
     public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException{  
          if ("abc".equalsIgnoreCase(localName)) {
              this.hasABC = true;
          }
      }
      @Override
      public void endElement(String namespaceURI, String localName, String qName) throws SAXException{
            if ("abc".equalsIgnoreCase(localName)) {
                 this.hasABC = false;
            }
       }
       @Override
       public void characters(char ch[], int start, int length){
            String content = new String(ch, start, length).trim(); 
            if(this.hasABC){
                 System.out.println("ABC = " + content);
            }
        }
    }

我发现解析器已经解析了标签两次系统打印出来的是，

I discover that the parser has parsed the tag two time System print out is,

ABC = abcdefghi

ABC = abcdefghi

ABC = jklmno <<============ 拆分消息

ABC = jklmno <<============ split the message

为什么解析器会自动回调 characters() 两次????

Why the parser auto call back the characters() two time????

XML 是否有一些 "或 "???

Is the XML haveing some " " or " " ???

推荐答案

Parser 多次调用 characters 方法，因为它可以并且允许每个规范.这有助于快速解析器并保持较低的内存占用.如果您想要单个字符串，请在 startElement 中创建一个新的 StringBuilder 对象，并在 endElement 方法上对其进行处理.

Parser is calling characters method more than one time, because it can and allowed per spec. This helps fast parser and keep their memory footprint low. If you want a single string create a new StringBuilder object in the startElement and process it on endElement method.

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