Java- can't call my method from another class

Question

I am trying create a simple card game. I have created four classes. One class holds a method for constructing a single card. Another class holds a method for making a deck from single cards. One class holds a method for shuffling the deck. And the fourth class is attempting to call each of these methods to create and shuffle a deck. I've looked through other posts on here so I believe I am calling the functions properly.
Here is the card constructor class:

package com.company;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import static javax.swing.WindowConstants.EXIT_ON_CLOSE;


public class Card_Class {
    private String suit, face;
    private int value;
    public BufferedImage cardImage;

    public Card_Class(String suit, String face, int value, BufferedImage card) {
        this.suit = suit;
        this.face = face;
        this.value = value;
        cardImage = card;


    }

Here is the deck constructor class (this class runs fine when calling the card constructor class)

package com.company;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;

import static javax.swing.WindowConstants.EXIT_ON_CLOSE;

public class Deck {

    public static Card_Class[] deckOfCards;
    private int currentCard;

    public Deck() throws IOException {

        String[] faces = {"Ace", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Jack", "Queen", "King"};
        String[] suits = {"Diamonds", "Clubs", "Hearts", "Spades"};
        deckOfCards = new Card_Class[52];
        currentCard = 0;

        final int width = 88;
        final int height = 133;
        final int rows =4;
        final int columns = 13;

        BufferedImage bigImage = ImageIO.read(new File("AllCards.png"));
        BufferedImage tempCardImage;

        for(int suit=0;suit <4; suit++){

            for(int face=0;face<13;face++){
                tempCardImage = bigImage.getSubimage(
                        face*width+(face*10)+8,
                        suit*height+(suit*10)+38,
                        width,
                        height);
                deckOfCards[(face+(suit*13))] = new Card_Class(suits[suit],faces[face],(13*suit+face),tempCardImage);
            }
        }

Now I have a class to shuffle cards:

package com.company;


public class ShuffleDeck {
    public static void main(String[] args) {
    }
    public static Object shuffle(Object[] cardDeck){
        int place = 0;
        for (int i = 0; i < cardDeck.length; i++) {
            int n = (int) Math.ceil(Math.random() * cardDeck.length - 1);
            Object a = cardDeck[i];
            cardDeck[i] = cardDeck[n];
            cardDeck[n] = a;
        }
        return cardDeck;
    }
}

And my last class attempts to call all three of the methods to create an object array of cards and shuffle them.

package com.company;


import java.io.IOException;

public class CardDealer {
    public static int[][] board = new int[4][14];
    Deck CardDeck = new Deck();
    ShuffleDeck riff = new ShuffleDeck();
    riff.shuffle(CardDeck);
}

The errors I get say 'Cannot resolve symbol shuffle' and 'Unknown class CardDeck'. Again I have looked at other posts and can't figure out what is wrong. I think I need to be doing something to 'shuffle' so the program can find a path to that method, but I'm not sure how to do this.

I'm really stuck here so any help would be appreciated.