In my last article, we learn about Multi-pane development in Android with Fragments(Multi-pane development in Android with Fragments).  Now we see how use Android XML Processing with the DOM Parser

There are three types of Android XML parsers – DOM, SAX and XmlPullParser.

Here is example of DOM. Document Object Modelis an application programming interface (API) for valid HTML and well-formed XML documents. It defines the logical structure of documents and the way a document is accessed and manipulated.

Here is an example XML file, and a DOM tree that illustrates the principle of turning XML into DOM:

<student>
    <id>101</id>
    <name>Zack</name>
    <age>25</age>
</student>

1.       Create your android project

2.      Add xml file in assets folder name should be student.xml and add following code 

student.xml contain records of student

<?xml version="1.0"   encoding="UTF-8"?>
<data>
<student>
<id>101</id>
<name>Michel Belly </name>
<age>21</age>
</student>
 
<student>
<id>102</id>
<name>Adney</name>
<age>27</age>
</student>
<student>
<id>103</id>
<name>Aiken Starch</name>
<age>27</age>
</student>
 
<student>
<name>Abbott</name>
<age>26</age>
</student>
 
<student>
<id>104</id>
<name>Alif</name>
<age>19</age>
</student>
 
<student>
<id>105</id>
<name>Kaarle</name>
<age>23</age>
</student>
 
<student>
<id>106</id>
<name>Maarku</name>
<age>22</age>
</student>
 
<student>
<id>107</id>
<name>Rahul</name>
<age>20</age>
</student>
 
<student>
<id>108</id>
<name>Salomao</name>
<age>25</age>
</student>
 
<student>
<id>109</id>
<name>David Warner</name>
<age>21</age>
</student>
<student>
<id>10</id>
<name>Zack</name>
<age>18</age>
</student>
</data>

3.   Add listview in activity_main 

<?xml version="1.0"   encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">
     <!--   Main ListView 
            Always give id  value as list(@android:id/list)
     -->
    <ListView
          android:id="@android:id/list"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"/>
 
</LinearLayout>

4.  Create layout xml file for show custom listview item name should be list_item.xml

<?xml version="1.0"   encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="#ffffff"
    android:orientation="vertical" >
 
    <!-- Name Label -->
 
    <TextView
          android:id="@+id/name"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:paddingBottom="2dip"
          android:paddingTop="6dip"
          android:text="Name"
          android:textColor="#282828"
          android:textSize="16sp"
          android:textStyle="bold"   />
    <!-- Description label -->
 
    <TextView
          android:id="@+id/age"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:paddingBottom="2dip"
          android:text="Age"
          android:textColor="#282828"   >
    </TextView>
 
</LinearLayout>

5.  Add another layout xml file name should be select_item  and paste following code 

<?xml version="1.0"   encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
 
    <!-- Name Label -->
 
    <TextView
          android:id="@+id/name_label"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:paddingBottom="10dip"
          android:paddingTop="10dip"
          android:textColor="#dc6800"
          android:textSize="25dip"
          android:textStyle="bold"   />
    <!-- Age Label -->
 
    <TextView
          android:id="@+id/description_label"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:textColor="#acacac"   />  
 
</LinearLayout>

6.  Create an XMLParser class and paste following code 

package com.androidhive.xmlparsing; 
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
 
public class XMLParser {
 
     //  constructor
     
 
 
     /**
      * Getting node value
      * 
      * @param elem
      *            element
      */
     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 "";
     }
 
     /**
      * Getting node value
      * 
      * @param Element
      *            node
      * @param key
      *            string
      * */
     public String getValue(Element item,  String str) {
           NodeList n = item.getElementsByTagName(str);
           return this.getElementValue(n.item(0));
     }
}

Add following code in MainActivity.class

package com.androidhive.xmlparsing;
 
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import  javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
 
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
 
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import  android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
 
public class MainActivity extends ListActivity {
 
     // All static variables
     // static final String URL =
 
     static final String KEY_ITEM = "student"; // parent node
     static final String KEY_ID = "id";
     static final String KEY_NAME = "name";
     static final String KEY_AGE = "age";
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.main);
           try {
 
                ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
 
                XMLParser parser = new XMLParser();
                // InputStream is a readable source of bytes.
                InputStream isStream = getAssets().open("student.xml");
        // DocumentBuilderFactory defines a factory API that enables
        // applications to obtain a
        // parser that produces DOM object trees from XML documents.
            DocumentBuilderFactory dbFactory = DocumentBuilderFactory
                           .newInstance();
            DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
                Document doc = dBuilder.parse(isStream);
        // NodeList objects in the DOM are live.
     // The items in the NodeList are accessible via an integral index,
        // starting from 0.
                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_ID, parser.getValue(e, KEY_ID));
          map.put(KEY_NAME, "Name -: " + parser.getValue(e, KEY_NAME));
          map.put(KEY_AGE, "Age -: " + parser.getValue(e, KEY_AGE));
                   // map.put(KEY_DESC, parser.getValue(e, KEY_DESC));
 
                     // adding HashList to ArrayList
                     menuItems.add(map);
                }
 
                // Adding menuItems to ListView
             ListAdapter adapter = new SimpleAdapter(this, menuItems,
                  R.layout.list_item, new String[] { KEY_NAME, KEY_AGE,
                         KEY_AGE }, new int[] { R.id.name, R.id.age });
 
                setListAdapter(adapter);
 
                // selecting single ListView item
                ListView lv = getListView();
 
               lv.setOnItemClickListener(new OnItemClickListener() {
 
                     @Override
              public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {
                           // getting values from selected ListItem
              String name = ((TextView) view.findViewById(R.id.name))
                                     .getText().toString();
 
                           String description = ((TextView) view
                         .findViewById(R.id.age)).getText().toString();
 
                           // Starting new intent
                     Intent in = new  Intent(getApplicationContext(),
                                     SingleMenuItemActivity.class);
                           // Pass value of selected item with intent
                           in.putExtra(KEY_NAME, name);
                           in.putExtra(KEY_AGE, description);
 
                           startActivity(in);
 
                     }
                });
           } catch (Exception ex) {
 
           }
     }
}

7.  Add another activity class name as SingleMenuItemActivity and add following code 

package  com.androidhive.xmlparsing;
 
import  android.app.Activity;
import  android.content.Intent;
import  android.os.Bundle;
import  android.widget.TextView;
 
public  class SingleMenuItemActivity extends Activity {
 
     // XML node keys
     static final String KEY_NAME =  "name";
 
     static final String KEY_AGE =  "age";
 
     @Override
     public void onCreate(Bundle  savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.select_item);
 
           // getting intent data
           Intent in = getIntent();
 
           // Get XML values from previous  intent
           String name =  in.getStringExtra(KEY_NAME);
 
           String description =  in.getStringExtra(KEY_AGE);
 
          //  Displaying all values on the screen
           TextView lblName = (TextView)  findViewById(R.id.name_label);
           TextView lblDesc = (TextView)  findViewById(R.id.description_label);
           lblName.setText(name);
 
           lblDesc.setText(description);
     }
}

And now run your application