This is the way, how to make grid decoration

ItemDecoration.java

//the function of this class is for customing and creating padding or margin for the recyclerview
    public class RecyclerViewMargin extends RecyclerView.ItemDecoration {

        //column is for accomodate the number of columns
        int columns;
        //margin is for accomodate the size of margin
        int margin;

        public RecyclerViewMargin(int margin, int columns) {
            //passing the margin from margin that defined outside to inside
            this.margin = margin;
            //passing the columns from column that defined outside to inside
            this.columns = columns;
        }

        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        
        //get the position to determine the condition of decoration
int position = parent.getChildLayoutPosition(view);

// == Right and Left margin==
outRect.right = margin;

//if the position is even(genap) then add left margin
//(when position in 0, 2, 4, 6, 8) give left margin, for example 0 / 2 = a  -> 0 = 2 x a, then a is 0 to get the 0 result in the left (0 = ..)
if (position % columns == 0) outRect.left = margin;
// == Right and Left margin==

// == Top and Bottom margin==
//if the position is in top or in 0 or 1 position then add the top margins
if (position < columns) outRect.top = margin;
outRect.bottom = margin;
// == Top and Bottom margin==
}
    }