XML parsing in android.

XML is a popular format for sharing data on the internet. Websites that frequently update their content, such as news sites or blogs, often provide an XML feed so that external programs can keep abreast of content changes. Uploading and parsing XML data is a common task for network-connected apps. This lesson explains how to parse XML documents and use their data.

This is the XML parser class:

Connection.java



public class Connection {

public String getXmlFromUrl(String url) {
String xml = null;

try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);

HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
xml = EntityUtils.toString(httpEntity);

} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// return XML
return xml;
}

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  ){
                        return child.getNodeValue();
                    }
                }
            }
        }
        return "";
 } 
}

This is the main class of the xml parsing which set the xml data to the listview:

XML_Parsing.java

public class XML_Parsing extends ListActivity {

    /** Called when the activity is first created. */

static final String URL = "http://..................../";               //URL for the xml data. 

   // XML node keys

    static final String KEY_ITEM = "item"; // parent node

    static final String KEY_NAME = "name";

    static final String KEY_EDUCATION = "education";

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();

        

        Connection parser = new Connection();

        String xml = parser.getXmlFromUrl(URL); // getting XML

        Document doc = parser.getDomElement(xml); // getting DOM element

 

        NodeList nl = doc.getElementsByTagName(KEY_ITEM);

        // looping through all item nodes <item>

        for (int i = 0; i < nl.getLength(); i++) {

            // creating new HashMap

            HashMap<String, String> map = new HashMap<String, String>();

            Element e = (Element) nl.item(i);

            // adding each child node to HashMap key => value

            map.put(KEY_NAME, parser.getValue(e, KEY_NAME));

            map.put(KEY_EDUCATION, parser.getValue(e, KEY_EDUCATION));

 

            // adding HashList to ArrayList

            menuItems.add(map);

        }

 

        // Adding menuItems to ListView

        ListAdapter adapter = new SimpleAdapter(this, menuItems,

                R.layout.row_data,

                new String[] { KEY_NAME, KEY_EDUCATION }, new int[] {

                        R.id.name, R.id.education });

 

        setListAdapter(adapter);

    }

}