How to detect the swipe left or Right in Android?

Simplest left to right swipe detector:

In your activity class add following attributes:

private float x1,x2;
static final int MIN_DISTANCE = 150;

and override onTouchEvent() method:

@Override
public boolean onTouchEvent(MotionEvent event)
{     
    switch(event.getAction())
    {
      case MotionEvent.ACTION_DOWN:
          x1 = event.getX();                          
      break;          
      case MotionEvent.ACTION_UP:
          x2 = event.getX();
          float deltaX = x2 - x1;
          if (Math.abs(deltaX) > MIN_DISTANCE)
          {
              Toast.makeText(this, "left2right swipe", Toast.LENGTH_SHORT).show ();
          }
          else
          {
              // consider as something else - a screen tap for example
          }                       
      break;    
    }            
    return super.onTouchEvent(event);        
}