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Groups > comp.lang.java.programmer > #12223

Re: java get xml file line number for the current node

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On 2/20/2012 9:32 AM, Arne Vajhøj wrote:
> On 2/20/2012 5:50 AM, mani wrote:
>> How can I now find the line number in the source XML file where this
>> node occurs?
>
> Using what parser? W3C DOM? SAX? StAX? JDOM?

If we assume:
- you use W3C DOM
- you only need line number for element nodes
- you really need it
- you are willing to write some ugly hacks
then try something like:

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.LinkedList;
import java.util.Queue;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.bootstrap.DOMImplementationRegistry;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSOutput;
import org.w3c.dom.ls.LSSerializer;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class ParseWithLineNumbers {
	public static  Document parseNormal(String fnm) throws 
ParserConfigurationException, SAXException, IOException {
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
         DocumentBuilder db = dbf.newDocumentBuilder();
		return db.parse(new File(fnm));
	}
	public static  Document parseSpecial(String fnm) throws 
ParserConfigurationException, SAXException, IOException {
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
         DocumentBuilder db = dbf.newDocumentBuilder();
		return db.parse(new InputSource(new SpecialReader(fnm)));
	}
	public static void print(Document doc) throws ClassCastException, 
ClassNotFoundException, InstantiationException, IllegalAccessException {
		DOMImplementation impl = 
DOMImplementationRegistry.newInstance().getDOMImplementation("XML 3.0");
		DOMImplementationLS feature = 
(DOMImplementationLS)impl.getFeature("LS","3.0");
         LSSerializer ser = feature.createLSSerializer();
         LSOutput output = feature.createLSOutput();
         output.setByteStream(System.out);
         ser.write(doc, output);
	}
	public static void main(String[] args) throws Exception {
		Document d1 = parseNormal("test.xml");
		print(d1);
		Document d2 = parseSpecial("test.xml");
		print(d2);
	}
}

class SpecialReader extends FileReader {
	private int lineno;
	private boolean inelm;
	private boolean eof;
	private Queue<Character> extra;
	public SpecialReader(String fnm) throws FileNotFoundException {
		super(fnm);
		lineno = 1;
		inelm = false;
		eof = false;
		extra = new LinkedList<Character>();
	}
	@Override
	public int read(char[] ch, int ix, int n) throws IOException {
		if(eof) return -1;
		int res = 0;
	wloop:
		while(res < n) {
			int c = extra.isEmpty() ? super.read() : extra.remove();
			if(inelm && (c == ' ' || c == '>')) {
	    		for(char xc : (" lineno='" + lineno +"'").toCharArray()) {
	    			extra.add(xc);
	    		}
	    		extra.add((char)c);
	    		c = extra.remove();
	    		inelm = false;
			}
			switch(c) {
			    case '\n' :
			    	lineno++;
			    	break;
			    case '<' :
			    	inelm = true;
			        break;
			    case '/':
			    	inelm = false;
			    	break;
			    case -1 :
			    	eof = true;
			    	break wloop;
			    default:
			    	/* nothing */
			    	break;
			}
			ch[ix + res] = (char)c;
			res++;
		}
		return res;
	}
}

It adds an attribute lineno to all elment nodes.

Arne

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Thread

java get xml file line number for the current node mani <mekalai82@gmail.com> - 2012-02-20 02:50 -0800
  Re: java get xml file line number for the current node Arne Vajhøj <arne@vajhoej.dk> - 2012-02-20 09:32 -0500
    Re: java get xml file line number for the current node Arne Vajhøj <arne@vajhoej.dk> - 2012-02-20 19:59 -0500
  Re: java get xml file line number for the current node Lew <noone@lewscanon.com> - 2012-02-20 11:58 -0800
    Re: java get xml file line number for the current node Gene Wirchenko <genew@ocis.net> - 2012-02-20 13:35 -0800
      Re: java get xml file line number for the current node Lew <noone@lewscanon.com> - 2012-02-20 14:42 -0800
        Re: java get xml file line number for the current node Arne Vajhøj <arne@vajhoej.dk> - 2012-02-20 19:57 -0500
          Re: java get xml file line number for the current node Gene Wirchenko <genew@ocis.net> - 2012-02-20 17:21 -0800
          Re: java get xml file line number for the current node Lew <noone@lewscanon.com> - 2012-02-20 17:27 -0800
    Re: java get xml file line number for the current node Arne Vajhøj <arne@vajhoej.dk> - 2012-02-20 19:57 -0500
    Re: java get xml file line number for the current node Roedy Green <see_website@mindprod.com.invalid> - 2012-02-20 18:00 -0800
    Re: java get xml file line number for the current node bugbear <bugbear@trim_papermule.co.uk_trim> - 2012-02-21 09:21 +0000
      Re: java get xml file line number for the current node Lew <noone@lewscanon.com> - 2012-02-21 09:15 -0800
        Re: java get xml file line number for the current node Gene Wirchenko <genew@ocis.net> - 2012-02-21 10:07 -0800
          Re: java get xml file line number for the current node Lew <noone@lewscanon.com> - 2012-02-21 11:50 -0800
  Re: java get xml file line number for the current node Jeff Higgins <jeff@invalid.invalid> - 2012-02-20 17:35 -0500
    Re: java get xml file line number for the current node Lew <noone@lewscanon.com> - 2012-02-20 14:46 -0800
      Re: java get xml file line number for the current node Jeff Higgins <jeff@invalid.invalid> - 2012-02-20 19:48 -0500

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