ScreenUtility.java

public class ScreenUtility {
	
	private Activity activity;
	private float dpWidth;
	private float dpHeight;

	public ScreenUtility(Activity activity) {
		this.activity = activity;

		Display display = activity.getWindowManager().getDefaultDisplay();

		DisplayMetrics outMetrics = new DisplayMetrics();

		display.getMetrics(outMetrics);

		float density = activity.getResources().getDisplayMetrics.density;
		dpHeight = outMetrics.heighPixels / density;
		dpWidth = outMetrics.widthPixels / density;
	}

	public float getWidth() { return dpWidth; }

	public float getHeight() { return dpHeight; }
}

//USAGE
//Declare an instance of the ScreenUtility class in your activity onCreate
//like
//ScreenUtility utility = new ScreenUtility(this);
//then
//utility.getWidth() and utility.getHeight() will return the appropriate values
//output 
//using Log to console or Toast to screen