In Android, the Canvas class has a method called drawRoundRect() that you can use to draw rounded corners on the edges of a drawn rectangle.
I would like to emphasize that using a value of 1 for both 2nd and 3rd parameters will not give you rounded corners. At least use 3.
Here is a sample code
Paint p = new Paint();
RectF rect = new RectF(10, 10, 50, 50);
c.drawRoundRect(rect, 3, 3, p);
This code draws a black colored rectangle and fills it using the same color.