import java.io.File;
import java.io.FileInputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.namespace.NamespaceContext;

import org.jaxen.JaxenException;
import org.jaxen.dom.DOMXPath;

import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

public class JaxenXPCheck
{
    public static void main(String[] args) throws Exception
    {
        (new JaxenXPCheck()).go(args);
        
    }

    private void go(String[] args) throws Exception
    {
        HashMap<String,String> map = new HashMap<String,String>();

        // Add all namespace declarations here...
        map.put("geo", "http://www.w3.org/2003/01/geo/wgs84_pos#");

        System.out.println();
        if ((args == null) || (args.length == 0))
        {
            runJaxen("//geo:lat[(text() >= 37.75)]", map);
            runJaxen("//geo:lat[(number(text()) >= 37.75)]", map);
        }
        else
        {
            for (String xp : args)
            {
                runJaxen(xp, map);
            }
        }
    }

    private void runJaxen(String xpExpr, Map<String,String> map)
        throws Exception
    {
        DummyNamespaceContext nsContext = new DummyNamespaceContext(map);

        // Set file name here.
        File file = new File("geodata.xml");

        // Get Document Builder Factory
        DocumentBuilderFactory factory =
            DocumentBuilderFactory.newInstance();

        factory.setNamespaceAware(true);
        factory.setIgnoringElementContentWhitespace(true);

        // Obtain a document builder object
        DocumentBuilder builder = factory.newDocumentBuilder();

        Document doc = builder.parse(file);
        org.jaxen.XPath xpObj = new DOMXPath(xpExpr);

        for (String key : nsContext.nsMappings.keySet())
        {
            xpObj.addNamespace(key, nsContext.nsMappings.get(key));
        }

        runXPath(doc, xpObj, xpExpr);
    }

    public static void runXPath(Document doc,
        org.jaxen.XPath xpath, String expr) throws Exception
    {
        List<Object> result = xpath.selectNodes(doc);
        System.out.println("Expr: " + expr + "\n");
        if (result == null)
        {
            System.out.println("  -=-> Found ZERO results.");
        }
        else
        {
            System.out.println("  -=-> Found list w/ " +
                result.size() + " matching nodes.");
        }

        System.out.println();
    }

    private class DummyNamespaceContext implements NamespaceContext
    {
        private final Map<String,String> nsMappings;
        public DummyNamespaceContext(Map<String,String> ns)
        {
            this.nsMappings = ns;
        }

        public String getNamespaceURI(String prefix)
        {
            return nsMappings.get(prefix);
        }

        public String getPrefix(String nsURI)
        {
            for (Map.Entry<String,String> entry : nsMappings.entrySet())
            {
                if (entry.getValue().equals(nsURI))
                {
                    return entry.getKey();
                }
            }

            return null;
        }

        public Iterator getPrefixes(String nsURI)
        {
            ArrayList prefixes = new ArrayList();
            for (Map.Entry<String,String> entry : nsMappings.entrySet())
            {
                if (entry.getValue().equals(nsURI))
                {
                    prefixes.add(entry.getKey());
                }
            }

            return prefixes.iterator();
        }
    }
}