A quick XPath analyser with a SAX Parser. Some syntaxes are invalides, but all using syntax are presents. It's possible to catch many XPath in the same time.

XPathXMLHandler handler=new XPathXMLHandler()
{
  @Override
  public void findXPathNode(SAXXPath xpath, Object node)
  {
     System.out.println("node="+node);
  }
};
handler.setXPaths(XPathXMLHandler.toXPaths("//b[@at_a='s3']/c"));
SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
parser.parse(new InputSource(new StringReader(xml)), handler);

The node is orphan, with attributs and all childs texts nodes. It's possible to use with HtmlParser.

XPathXMLHandler handler=new XPathXMLHandler()
{
  @Override
  public void findXpathNode(SAXXPath xpath, Object node)
  {
     System.out.println("node="+node);
  }
};
handler.setXPaths(XPathXMLHandler.toXPaths("//body/h1"));
HtmlParser htmlParser = new HtmlParser(XmlViolationPolicy.ALLOW);
htmlParser.setDoctypeExpectation(DoctypeExpectation.NO_DOCTYPE_ERRORS);
htmlParser.setContentHandler(handler);
htmlParser.parse(new InputSource(new StringReader(html)));

Accepted syntax

Valide syntax

• "'fixe'"
• "1"
• "/"
• "/a/b/c"
• "/a/text()"
• "/a/@at_a"
• "/a/b/@*"
• "/a/b[@*]"
• "/a/b[@at_a = 's3']"
• "/a/b[@at_a > 2]"
• "/a/b[@at_a >= 2]"
• "/a/b[@at_a = @at_b]"
• "/a/b[@at_a != @at_b]"
• "/a/b[@at_a < 5]"
• "/a/b[@at_a <= 2]"
• "/a/b[@at_b='s2' or @at_b='3']"
• "/a/b[@at_a='3' and @at_b='3']"
• "/a/b/text()['toto']"
• "/a/b[2]"
• "/a/b/text()[2]"
• "/a/b/@*[2]"
• "//b/c"
• "//b/c[2]"
• "//b[2]/c[2]"
• "//b[@at_a='s3']/c"
• "//c/text()"
• "//b/@at_a"
• "//@at_a"

Invalide syntax

• "//text()"
• "//@*"
• using dot, node(), functions, etc.
• using double predicat ("/a/b[@at_a][1]")
• using or ("/a | /b")