Sax parsing and encoding

问题

I have a contact that is experiencing trouble with SAX when parsing RSS and Atom files. According to him, it's as if text coming from the Item elements is truncated at an apostrophe or sometimes an accented character. There seems to be a problem with encoding too.

I've given SAX a try and I have some truncating taking place too but haven't been able to dig further. I'd appreciate some suggestions if someone out there has tackled this before.

This is the code that's being used in the ContentHandler:

public void characters( char[], int start, int end ) throws SAXException {
//
    link = new String(ch, start, end);

Edit: The encoding problem might be due to storing information in a byte array as I know Java works in Unicode.

回答1:

The characters() method is not guaranteed to give you the complete character content of a text element in one pass - the full text may span buffer boundaries. You need to buffer the characters yourself between the start and end element events.

e.g.

StringBuilder builder;

public void startElement(String uri, String localName, String qName, Attributes atts) {
   builder = new StringBuilder();
}

public void characters(char[] ch, int start, int length) {
   builder.append(ch,start,length);
}

public void endElement(String uri, String localName, String qName) {
  String theFullText = builder.toString();
}

回答2:

XML entities generate special events in SAX. You can catch them with a LexicalHandler, though it's generally not necessary. But this explain why can't assume that you will recieve only one characters event per tag. Use a buffer as explained in other answers.

For instance hello&world will generate the sequence