How scan the data through Aadhar Card in Android.


First we need to add Library to our project.

compile 'com.journeyapps:zxing-android-embedded:2.0.1@aar'  
compile 'com.journeyapps:zxing-android-legacy:2.0.1@aar'
compile 'com.journeyapps:zxing-android-integration:2.0.1@aar'
compile 'com.google.zxing:core:3.0.1'

Creating New Project.
Open android studio and create a new project.

File => New => New Project => Configure your new project => Select the form factor yours app will run on => Add an Activity to Mobile => Customize the Activity => Finish.

Create the Java file in project.
Open app => main => src = MainActivity.java


Create Xml file in project.    
Open => app => res => layout - activity_main.xml.

 <LinearLayout
        android:id="@+id/ll_scan_qr_wrapper"
        android:layout_width="match_parent"
        android:layout_height="72dp"
        android:background="#fff"
        android:padding="8dp"
        android:orientation="horizontal"
        android:onClick="scanNow">
        <!-- scanner -->
        <LinearLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1.50">
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:src="@mipmap/qr_scanner"/>
        </LinearLayout>

Create the Java file in project.
Open app => main => src = MainActivity.java

  String uid,user_name,gender,yearOfBirth,careOf,villageTehsil,postOffice,district,state,postCode;
 LinearLayout ll_scanned_data_wrapper = (LinearLayout)findViewById(R.id.ll_scan_qr_wrapper);

/**
     * onclick handler for scan new card
     * @param view
     */
    public void scanNow( View view){
        IntentIntegrator integrator = new IntentIntegrator(this);
        integrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE_TYPES);
        integrator.setPrompt("Scan a Aadharcard QR Code");
        integrator.setResultDisplayDuration(500);
        integrator.setCameraId(0);  // Use a specific camera of the device
        integrator.initiateScan();
    }

    /**
     * function handle scan result
     * @param requestCode
     * @param resultCode
     * @param intent
     */
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent)
    {
        super.onActivityResult(requestCode, resultCode, intent);
        callbackManager.onActivityResult(requestCode, resultCode, intent);
        //retrieve scan result
        IntentResult scanningResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);

        if (scanningResult != null) {
            //we have a result
            String scanContent = scanningResult.getContents();
            String scanFormat = scanningResult.getFormatName();

            // process received data
            if(scanContent != null && !scanContent.isEmpty()){
                processScannedData(scanContent);
            }else{

            }

        }else{

        }
    }
    /**
     * process xml string received from aadhaar card QR code
     * @param scanData
     */
    protected void processScannedData(String scanData){

        XmlPullParserFactory pullParserFactory;

        try {
            // init the parserfactory
            pullParserFactory = XmlPullParserFactory.newInstance();
            // get the parser
            XmlPullParser parser = pullParserFactory.newPullParser();

            parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, false);
            parser.setInput(new StringReader(scanData));

            // parse the XML
            int eventType = parser.getEventType();
            while (eventType != XmlPullParser.END_DOCUMENT) {
                if(eventType == XmlPullParser.START_DOCUMENT) {

                } else if(eventType == XmlPullParser.START_TAG && DataAttributes.AADHAAR_DATA_TAG.equals(parser.getName())) {
                    // extract data from tag
                    //uid
                    uid = parser.getAttributeValue(null,DataAttributes.AADHAR_UID_ATTR);
                    //name
                    user_name = parser.getAttributeValue(null,DataAttributes.AADHAR_NAME_ATTR);
                    //gender
                    gender = parser.getAttributeValue(null,DataAttributes.AADHAR_GENDER_ATTR);
                    // year of birth
                    yearOfBirth = parser.getAttributeValue(null,DataAttributes.AADHAR_YOB_ATTR);
                    // care of
                    careOf = parser.getAttributeValue(null, DataAttributes.AADHAR_CO_ATTR);
                    // village Tehsil
                    villageTehsil = parser.getAttributeValue(null,DataAttributes.AADHAR_VTC_ATTR);
                    // Post Office
                    postOffice = parser.getAttributeValue(null,DataAttributes.AADHAR_PO_ATTR);
                    // district
                    district = parser.getAttributeValue(null,DataAttributes.AADHAR_DIST_ATTR);
                    // state
                    state = parser.getAttributeValue(null,DataAttributes.AADHAR_STATE_ATTR);
                    // Post Code
                    postCode = parser.getAttributeValue(null,DataAttributes.AADHAR_PC_ATTR);

                } else if(eventType == XmlPullParser.END_TAG) {


                } else if(eventType == XmlPullParser.TEXT) {


                }
                // update eventType
                eventType = parser.next();
            }

            // display the data on screen
          displayScannedData();
        } catch (XmlPullParserException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }// EO function

    /**
     * show scanned information
     */
    public void displayScannedData(){

        String mName=user_name;
        String mUid=uid;
        String name=gender;
    
    }


Add Internet permission in your manifest.
<uses-permission android:name="android.permission.INTERNET" />