How to Parse XML file Using Dom Parsing?

Question

My Problem is I am Using Dom Parsing to parse below xml file but this give me error of NullPointerException.

Any Help Would be Appreciated.

MainActivity.java

Answer 1

try this

create a new class XMLParser

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

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

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import android.util.Log;

public class XMLParser {

    public String getXmlFromUrl(String urll) {
        String response = "";
        try {
            URLConnection conn = null;
            InputStream inputStream = null;
            URL url = new URL(urll);
            conn = url.openConnection();
            conn.setConnectTimeout(10000);
            HttpURLConnection httpConn = (HttpURLConnection) conn;
            httpConn.setRequestMethod("GET");
            httpConn.setConnectTimeout(10000);
            httpConn.connect();
            if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                inputStream = httpConn.getInputStream();
            }
            BufferedReader in = new BufferedReader(new InputStreamReader(inputStream));
            StringWriter writer=new StringWriter();
            String line="";
            while ( null!=(line=in.readLine())){
                writer.write(line); 
            }
            response =writer.toString(); 
            }
        catch (Exception e) {
            // TODO: handle exception
        }
        return response;
    }

    public Document getDomElement(String xml) {
        Document doc = null;
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        try {

            DocumentBuilder db = dbf.newDocumentBuilder();

            InputSource is = new InputSource();
            is.setCharacterStream(new StringReader(xml));
            doc = db.parse(is);

        } catch (ParserConfigurationException e) {
            Log.e("Error: ", e.getMessage());
            return null;
        } catch (SAXException e) {
            Log.e("Error: ", e.getMessage());
            return null;
        } catch (IOException e) {
            Log.e("Error: ", e.getMessage());
            return null;
        }
        // return DOM
        return doc;
    }

    public String getValue(Element item, String str) {
        NodeList n = item.getElementsByTagName(str);
        return this.getElementValue(n.item(0));
    }

    public final String getElementValue(Node elem) {
        Node child;
        if (elem != null) {
            if (elem.hasChildNodes()) {
                for (child = elem.getFirstChild(); child != null; child = child
                        .getNextSibling()) {
                    if (child.getNodeType() == Node.TEXT_NODE || child.getNodeType() == Node.CDATA_SECTION_NODE) {
                        return child.getNodeValue();
                    }
                }
            }
        }
        return "";
    }
}

your xml for example

   
     
     description1
     lien1
   
   
     
     description2
     lien2
   

and, to use it in your Activity

final String KEY_ITEM = "result"; // parent node
final String KEY_TITLE = "title";
final String KEY_DESC = "description";
final String KEY_LINK = "lien";


XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl("YourXmlURL"); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element

NodeList elements = doc.getElementsByTagName(KEY_ITEM);
List title= new ArrayList(); // or other type
List descp= new ArrayList();
Element e;

for (int i = 0; i < elements.getLength(); i++) {
    e = (Element) elements.item(i);
    title.add(parser.getValue(e, KEY_TITLE));
    descp.add(parser.getValue(e,KEY_DESC));
}