XML Parsing in Android

XML Parsing in Android Using DOM

What is an XML(Extensible Markup Language)?

Ans:  XML stands for Extensible Markup Language.XML was defined by W3C(World Wide Web Consortium).

An XML document consists of elements, each element has a start tag and an end tag,in between that content will be there.An XML file must be "well-formed".An XML file is called valid if it is well-formed.

An Well-formed xml look like bellow:

<?xml version="1.0"?>

<car>

  <name>BMW</name>

  <cost>2500000</cost>

</car>

XML Parsers in Android

Android supports two types of XML Parsers:

      1.    DOM(Document Object Model) Parser

      2.    SAX(Simple API for XML) Parser

 In this tutorial we will see how DOM(Document Object Model) parsing hapenning in android. To parse the xml file, we need xml data. So at first we will create a xml file, then we will parse it in our android device.

To Create XML file, see bellow steps:

Go to your Notepad application, Type the following code:

<?xml version="1.0"?> 

<computers> 

<brand> 

    <name>Apple</name> 

    <cost>45000</cost> 

</brand> 

<brand> 

     <name>Dell</name> 

     <cost>40000</cost> 

</brand> 

<brand> 

     <name>HP</name> 

     <cost>35000</cost> 

</brand> 

</computers>  

Then go File-> Save as -> testxml.xml.

After generating  this xml file, put this xml file Under assets folder in your android project.See Bellow how it will look like:

Creating Android Application Project for XML Parsing:

In Eclipse -> Create New Project(Named as TestDomParser). -> Provide Activity Name(Here name as MainActivity). This application building Android Version 4.2.2, API level 17.

MainActivity.java will look like this:

public class MainActivity extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        TextView tv_parse =(TextView)findViewById(R.id.tv);

        try{

            InputStream is = getAssets().open("testxml.xml");

            DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();

            DocumentBuilder dbBuilder = dbFactory.newDocumentBuilder();

            Document doc = dbBuilder.parse(is);

           

            Element element=doc.getDocumentElement(); 

            element.normalize();

           

            NodeList nList = doc.getElementsByTagName("brand");

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

                        Node node = nList.item(i); 

                        if (node.getNodeType() == Node.ELEMENT_NODE) { 

                                    Element elmnt = (Element) node; 

                                    tv_parse.setText(tv_parse.getText()+"\nCompany Name: " +                                                             getValue("name", elmnt)+"\n"); 

                                    tv_parse.setText(tv_parse.getText()+"Price: " + getValue("cost",                                                     elmnt)+"\n"); 

                                    tv_parse.setText(tv_parse.getText()+"**********************"); 

                                    } 

            }

        }catch(Exception e){

            e.printStackTrace();

        }

    }

    private static String getValue(String tag, Element element) { 

            NodeList nodeList = element.getElementsByTagName(tag).item(0).getChildNodes(); 

            Node node = (Node) nodeList.item(0); 

            return node.getNodeValue(); 

            } 

   

}

Activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

    <TextView

        android:id="@+id/tv"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentLeft="true"

        android:layout_alignParentTop="true"

        android:textStyle="bold"

        android:textSize="15sp"

        android:layout_marginLeft="16dp"

        android:layout_marginTop="14dp"

        android:text="" />

</RelativeLayout>

Result: