cryptographic systems

http://www.javacodegeeks.com/2012/02/introduction-to-strong-cryptography-p1.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+JavaCodeGeeks+%28Java+Code+Geeks%29&utm_content=Google+Reader

http://www.javacodegeeks.com/2012/02/android-read-file-from-assets.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+JavaCodeGeeks+%28Java+Code+Geeks%29&utm_content=Google+Reader

Exercise AndroidMapper, Android Application using MapView

In the previous exercises, the MapView track the GPS and center on it repeatly. In this exercise, AndroidMapper, it will not track on GPS. Instead, there are three options to center in starting of the MapView.
- Default: Start ViewMap without any center location.
- GPS: It's the current GPS (which will be track before ViewMap start). If no valid GPS, this option will be disable.
- Location: User input location. If no location input, this option will be disable.

This application is not yet finished, more feature (or bug fixed) will be added in the furture.

Create a Android Application named, AndroidMapper.
Package Name: com.AndroidMapper
Target Google Platform 2.0 with Google APIs.

Modify main.xml to have the UI as seen in the picture.


LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"

TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/
RadioGroup
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
RadioButton
android:id="@+id/option_default"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Default Location" /
RadioButton
android:id="@+id/option_gps"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="GPS:" /
android:id="@+id/option_location"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Location:" /
RadioGroup
TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="latitude"
/
EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/latitude"
android:inputType="numberDecimal"
/
TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="longitude"
/
EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/longitude"
android:inputType="numberDecimal"
/
Button
android:id="@+id/loadmap"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Load Map"
/
LinearLayout


import com.google.android.maps.GeoPoint;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;

public class AndroidMapper extends Activity {

private LocationManager myLocationManager;
private LocationListener myLocationListener;
private GeoPoint GeoPoint_GPS, GeoPoint_Location;

RadioButton myoption_default, myoption_gps, myoption_location;
EditText mylatitude, mylongitude;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

loadMenu();
validGPS();
validLocation();

myLocationManager = (LocationManager)getSystemService(
Context.LOCATION_SERVICE);

myLocationListener = new MyLocationListener();

myLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
0,
0,
myLocationListener);
}

private void loadMenu()
{
setContentView(R.layout.main);
myoption_default = (RadioButton)findViewById(R.id.option_default);
myoption_gps = (RadioButton)findViewById(R.id.option_gps);
myoption_location = (RadioButton)findViewById(R.id.option_location);
mylatitude = (EditText)findViewById(R.id.latitude);
mylongitude = (EditText)findViewById(R.id.longitude);

mylatitude.setOnKeyListener(locationOnKeyListener);
mylongitude.setOnKeyListener(locationOnKeyListener);

Button myLoadMapButton = (Button)findViewById(R.id.loadmap);
myLoadMapButton.setOnClickListener(myLoadMapButtonOnClickListener);
}

Button.OnClickListener myLoadMapButtonOnClickListener =
new Button.OnClickListener(){

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(myoption_default.isChecked()){
OpenIntentAndroidMapView(null);
}
else if(myoption_gps.isChecked()){
OpenIntentAndroidMapView(GeoPoint_GPS);
}
else if(myoption_location.isChecked()){
OpenIntentAndroidMapView(GeoPoint_Location);
}
else{
OpenMissingOptionDialog();
}

}

};

private void OpenIntentAndroidMapView(GeoPoint startLocation)
{
Intent intent = new Intent();
intent.setClass(AndroidMapper.this, AndroidMapView.class);

Bundle bundle = new Bundle();

if (startLocation == null)
{
bundle.putInt("Mode", 0);
}
else
{
bundle.putInt("Mode", 1);
bundle.putInt("Longitude", startLocation.getLongitudeE6());
bundle.putInt("Latitude", startLocation.getLatitudeE6());
}

intent.putExtras(bundle);
startActivityForResult(intent, 0);
}

private void OpenMissingOptionDialog()
{
new AlertDialog.Builder(this)
.setTitle("missing selection")
.setMessage("Please select one of the option")
.setPositiveButton("OK",
new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialoginterface, int i)
{}
})
.show();
}

EditText.OnKeyListener locationOnKeyListener =
new EditText.OnKeyListener(){

@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
validLocation();
return false;
}

};

private void validGPS()
{
GeoPoint_GPS = loadGPS();
if (GeoPoint_GPS==null)
{
myoption_gps.setClickable(false);
}
else
{
myoption_gps.setText("GPS: (" +
String.valueOf((float)GeoPoint_GPS.getLatitudeE6()/1000000) +" : " +
String.valueOf((float)GeoPoint_GPS.getLongitudeE6()/1000000) +")");
myoption_gps.setClickable(true);
}
}

private void validLocation()
{
/*
Toast.makeText(AndroidMapper.this,
mylatitude.getText().toString(),
Toast.LENGTH_LONG).show();*/
if (mylatitude.getText().toString().equals("") || mylongitude.getText().toString().equals(""))
{

myoption_location.setText("Location: ");
myoption_location.setClickable(false);
myoption_location.setChecked(false);
}
else
{
float locationLatitude = Float.parseFloat(mylatitude.getText().toString());
float locationLongitude = Float.parseFloat(mylongitude.getText().toString());

myoption_location.setText("Location: (" +
String.valueOf(locationLatitude) +" : " +
String.valueOf(locationLongitude) +")");
myoption_location.setClickable(true);
myoption_location.setChecked(true);

GeoPoint_Location = new GeoPoint(
(int)(locationLatitude*1000000),
(int)(locationLongitude*1000000));
}
}

private GeoPoint loadGPS()
{
//Get the current location from GPS
myLocationManager = (LocationManager)getSystemService(
Context.LOCATION_SERVICE);
Location initLocation=myLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(initLocation != null)
{
return (
new GeoPoint(
(int)(initLocation.getLatitude()*1000000),
(int)(initLocation.getLongitude()*1000000)));
}
else
return null;
}

private class MyLocationListener implements LocationListener{

@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
GeoPoint_GPS = new GeoPoint(
(int)(location.getLatitude()*1000000),
(int)(location.getLongitude()*1000000));
myoption_gps.setText("GPS: (" +
String.valueOf((float)GeoPoint_GPS.getLatitudeE6()/1000000) +" : " +
String.valueOf((float)GeoPoint_GPS.getLongitudeE6()/1000000) +")");
myoption_gps.setClickable(true);
}

@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub

}

@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub

}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub

}

}

LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"

LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"

LinearLayout
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"

CheckBox
android:id="@+id/satellite"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=" Satellite "
/
/LinearLayout
LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"

TextView
android:id="@+id/longitude"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Longitude:"
/
TextView
android:id="@+id/latitude"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Latitude:"
/
/LinearLayout
/LinearLayout
com.google.android.maps.MapView
android:id="@+id/mapview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="true"
android:apiKey=""
/



import android.os.Bundle;
import android.view.View;
import android.widget.CheckBox;
import android.widget.TextView;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;

public class AndroidMapView extends MapActivity {

private TextView myLongitude, myLatitude;
private CheckBox mySatellite;

private MapView myMapView;
private MapController myMapController;

private void SetSatellite()
{
myMapView.setSatellite(mySatellite.isChecked());
};

@Override
protected void onCreate(Bundle icicle) {
// TODO Auto-generated method stub
super.onCreate(icicle);
setContentView(R.layout.mymapview);

Bundle bundle = this.getIntent().getExtras();
int Mode = bundle.getInt("Mode");

myMapView = (MapView)findViewById(R.id.mapview);
myMapController = myMapView.getController();
myMapView.setBuiltInZoomControls(true);

myLongitude = (TextView)findViewById(R.id.longitude);
myLatitude = (TextView)findViewById(R.id.latitude);
mySatellite = (CheckBox)findViewById(R.id.satellite);
mySatellite.setOnClickListener(mySatelliteOnClickListener);

SetSatellite();


if(Mode == 1)
{
int intLatitude = bundle.getInt("Latitude");
int intLongitude = bundle.getInt("Longitude");
GeoPoint initGeoPoint = new GeoPoint(intLatitude, intLongitude);
CenterLocation(initGeoPoint);
}


}



@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}

private void CenterLocation(GeoPoint centerGeoPoint)
{
myMapController.animateTo(centerGeoPoint);


myLongitude.setText("Longitude: "+
String.valueOf((float)centerGeoPoint.getLongitudeE6()/1000000)
);
myLatitude.setText("Latitude: "+
String.valueOf((float)centerGeoPoint.getLatitudeE6()/1000000)
);
};

private CheckBox.OnClickListener mySatelliteOnClickListener =
new CheckBox.OnClickListener(){

public void onClick(View v) {
// TODO Auto-generated method stub
SetSatellite();
}
};

}

xmlns:android="http://schemas.android.com/apk/res/android"
package="com.AndroidMapper"
android:versionCode="1"
android:versionName="1.0"
application android:icon="@drawable/icon" android:label="@string/app_name"
activity android:name=".AndroidMapper"
android:label="@string/app_name"
intent-filter
action android:name="android.intent.action.MAIN" /
category android:name="android.intent.category.LAUNCHER" /
/intent-filter
/activity
activity android:name=".AndroidMapView"
/activity
uses-library android:name="com.google.android.maps" /
/application
uses-permission android:name="android.permission.INTERNET" /
uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /
uses-sdk android:minSdkVersion="5" /

AndroidLocation: with a CheckBox to toggle MapView.setSatellite()

LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"

LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"

LinearLayout
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"

CheckBox
android:id="@+id/satellite"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=" Satellite "
/
/LinearLayout
LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
android:id="@+id/longitude"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Longitude:"
/
TextView
android:id="@+id/latitude"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Latitude:"
/
/LinearLayout
/LinearLayout
SeekBar
android:id="@+id/zoombar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:max="20"
android:progress="0"/
com.google.android.maps.MapView
android:id="@+id/mapview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="false"
android:apiKey=""
/
/LinearLayout


import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;

import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.widget.CheckBox;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidLocation extends MapActivity {

private LocationManager myLocationManager;
private LocationListener myLocationListener;
private TextView myLongitude, myLatitude;
private CheckBox mySatellite;

private MapView myMapView;
private SeekBar myZoomBar;

private MapController myMapController;

private void CenterLocation(GeoPoint centerGeoPoint)
{
myMapController.animateTo(centerGeoPoint);


myLongitude.setText("Longitude: "+
String.valueOf((float)centerGeoPoint.getLongitudeE6()/1000000)
);
myLatitude.setText("Latitude: "+
String.valueOf((float)centerGeoPoint.getLatitudeE6()/1000000)
);
};

private void SetZoomLevel()
{
int myZoomLevel = myZoomBar.getProgress()+1;
myMapController.setZoom(myZoomLevel);
Toast.makeText(this,
"Zoom Level : " + String.valueOf(myZoomLevel),
Toast.LENGTH_LONG).show();
};

private void SetSatellite()
{
myMapView.setSatellite(mySatellite.isChecked());
};

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
myMapView = (MapView)findViewById(R.id.mapview);
myLongitude = (TextView)findViewById(R.id.longitude);
myLatitude = (TextView)findViewById(R.id.latitude);
myZoomBar = (SeekBar)findViewById(R.id.zoombar);
mySatellite = (CheckBox)findViewById(R.id.satellite);

SetSatellite();
myMapController = myMapView.getController();
SetZoomLevel();

myLocationManager = (LocationManager)getSystemService(
Context.LOCATION_SERVICE);

myLocationListener = new MyLocationListener();

myLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
0,
0,
myLocationListener);

//Get the current location in start-up
//check LastKnownLocation, if not valid, skip it.
Location initLocation=myLocationManager.getLastKnownLocation(
LocationManager.GPS_PROVIDER);
if(initLocation != null)
{
GeoPoint initGeoPoint = new GeoPoint(
(int)(initLocation.getLatitude()*1000000),
(int)(initLocation.getLongitude()*1000000));
CenterLocation(initGeoPoint);
}
myZoomBar.setOnSeekBarChangeListener(myZoomBarOnSeekBarChangeListener);
mySatellite.setOnClickListener(mySatelliteOnClickListener);
}

private CheckBox.OnClickListener mySatelliteOnClickListener =
new CheckBox.OnClickListener(){

public void onClick(View v) {
// TODO Auto-generated method stub
SetSatellite();
}

};

private SeekBar.OnSeekBarChangeListener myZoomBarOnSeekBarChangeListener =
new SeekBar.OnSeekBarChangeListener(){

public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
// TODO Auto-generated method stub
SetZoomLevel();
}

public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub

}

public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub

}

};

private class MyLocationListener implements LocationListener{

public void onLocationChanged(Location argLocation) {
// TODO Auto-generated method stub
GeoPoint myGeoPoint = new GeoPoint(
(int)(argLocation.getLatitude()*1000000),
(int)(argLocation.getLongitude()*1000000));

CenterLocation(myGeoPoint);
}

public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}

public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}

public void onStatusChanged(String provider,
int status, Bundle extras) {
// TODO Auto-generated method stub
}
}

@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
};
}

Status Bar Notifications

A status bar notification adds an icon to the system's status bar (with an optional ticker-text message) and an expanded message in the "Notifications" window.
After Notification generated, a selected notification icon and Ticket will be displayed on the status bar.

User can reveal the Notifications window by pulling down the status bar (or selecting Notifications from the Home options menu), to view the Title and Content.

Notification can be generated inside Service or Activity. This exercise show the basic steps to generate a Notification in Activity.

The most important class is NotificationManager and Notification.

In the exercise:
android.R.drawable.btn_star_big_on is a drawable icon in Android system resource, you can assign any drawable icon.
when is when the notification should be generated, System.currentTimeMillis() = NOW.
NOTIFICATION_ID is a number which is unique in your application.
contentIntent is the expected intent to handle the notification. It's the own activity in this exercise.

The generated Notification can be cleared by:
NotificationManager.cancel(NOTIFICATION_ID);
TextView

LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"

Button

android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"

Button

 android:id="@+id/gen"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Generate Notification"

 android:id="@+id/clear"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Clear Notification"

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class AndroidNotification extends Activity {

 NotificationManager myNotificationManager;
 private static final int NOTIFICATION_ID = 1;
 
 /** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Button myGen = (Button)findViewById(R.id.gen);
    myGen.setOnClickListener(myGenOnClickListener);
    Button myClear = (Button)findViewById(R.id.clear);
    myClear.setOnClickListener(myClearOnClickListener);


}

private void GeneratNotification(){
  
  myNotificationManager =
   (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
  
  CharSequence NotificationTicket = "*** Notification";
  CharSequence NotificationTitle = "Attention Please!";
  CharSequence NotificationContent = "- Notification is coming -";
  long when = System.currentTimeMillis();
  
  Notification notification =
   new Notification(android.R.drawable.btn_star_big_on,
     NotificationTicket, when);
    
  Context context = getApplicationContext();

  Intent notificationIntent = new Intent(this,
   AndroidNotification.class);
  PendingIntent contentIntent =
   PendingIntent.getActivity(this, 0, notificationIntent, 0);

  notification.setLatestEventInfo(context, NotificationTitle,
    NotificationContent, contentIntent);
  
  myNotificationManager.notify(NOTIFICATION_ID, notification);

}

Button.OnClickListener myGenOnClickListener =
 new Button.OnClickListener(){

  @Override
  public void onClick(View v) {
   // TODO Auto-generated method stub
   GeneratNotification();
  }
 
};

Button.OnClickListener myClearOnClickListener =
 new Button.OnClickListener(){

  @Override
  public void onClick(View v) {
   // TODO Auto-generated method stub
   myNotificationManager.cancel(NOTIFICATION_ID);
  }
 
};
}

Layout Animation

Layout Animation can be used to add visual effects on any controls derived from ViewGroup, such as ListView. ListView is a view that shows items in a vertically scrolling list. The items come from the ListAdapter associated with this view.

In this article, I will have a example to show how to implement a simple Layout Animation.


Create a Android Application named AndroidLayoutAnimation.

- Create a new folder named /anim under /res

- Create two xml file under /res/anim to handle the animation
list_layout_controller.xml

layoutAnimation xmlns:android="http://schemas.android.com/apk/res/android"
 android:delay="50%"
 android:animation="@anim/scale"

scale

set xmlns:android="http://schemas.android.com/apk/res/android"
 android:interpolator="@android:anim/accelerate_interpolator"

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

  android:fromXScale="0.1"
  android:toXScale="1"
  android:fromYScale="0.1"
  android:toYScale="1.0"
  android:duration="2000"
  android:pivotX="10%"
  android:pivotY="10%"
  android:startOffset="100"

ListView

 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"

Button

  android:id="@+id/myListView"
  android:persistentDrawingCache="animation|scrolling"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layoutAnimation="@anim/list_layout_controller"

  android:id="@+id/myRestartButton"
  android:layout_width="fill_parent" 
     android:layout_height="wrap_content"
     android:text="Restart"

Modify AndroidLayoutAnimation.java to setContentView() using listlayout.xml, and SetupListView(). In order to show the effect, a button is used to restart the animation.

package com.exercise.AndroidLayoutAnimation;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;

public class AndroidLayoutAnimation extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        loadScreen();
    }
    
    private Button.OnClickListener MyRestartButtonOnClickListener
     = new Button.OnClickListener(){

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    loadScreen();
   }
    };
    
    private void loadScreen(){
     setContentView(R.layout.main);
        SetupListView();
        
        Button MyRestartButton = (Button)findViewById(R.id.myRestartButton);
        MyRestartButton.setOnClickListener(MyRestartButtonOnClickListener);
    }
    
    private void SetupListView()
    {
     String[] listItems = new String[] {
       "Hello!",
       "It's a Demo to use Layout Animation",
       "Is it Great?",
       "android-er.blogspot.com"
     };

     ArrayAdapter listItemAdapter 
       = new ArrayAdapter(
         this, 
         android.R.layout.simple_list_item_1, 
         listItems);
       
     ListView lv = (ListView)this.findViewById(R.id.myListView);
     lv.setAdapter(listItemAdapter);
    }
}

AndroidRunnable, with Runnable Thread.

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.TextView;

public class AndroidRunnable extends Activity{
 
 int i = 0;
 TextView myi;
 
 Handler handler = new Handler(){

  @Override
  public void handleMessage(Message msg) {
   // TODO Auto-generated method stub
   update_i();
  }
 };
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        myi =(TextView)findViewById(R.id.i);
    }
    
    @Override
 protected void onStart() {
  // TODO Auto-generated method stub
  super.onStart();
  
  Thread myThread=new Thread(new Runnable() {
   public void run() {
    while(true){
     try {
      handler.sendMessage(handler.obtainMessage());
      Thread.sleep(1000);
     }
     catch (Throwable t) {
     }
    }
   }
  });
   
  myThread.start();
 }

 private void update_i()
    {
     i++;
     myi.setText(String.valueOf(i));
    }
}

Perform stress-test on your applications using Monkey, a UI/Application Exerciser

The Monkey is a program that runs on your emulator or device and generates pseudo-random streams of user events such as clicks, touches, or gestures, as well as a number of system-level events. You can use the Monkey to stress-test applications that you are developing, in a random yet repeatable manner.
The simplest way to use the monkey is with the following command, which will launch your application and send 500 pseudo-random events to it.

$ adb shell monkey -v -p your.package.name 500

For more information about command options for Monkey, see the complete UI/Application Exerciser Monkey documentation page.