To manage form flow, the first thing you need to do is create a singleton class with static methods. Next, you implement a stackable system in which to store any object. The showPrevious() method exposes objects’ special data.

package tips.formstack;import java.util.Stack;public class FormFlow {	private static Stack stack = new Stack();		public static void addInstance(Object instance) {		stack.push(instance);	}	public static Object getInstance() {		return stack.pop();	}		public static void showPrevious() {		((Showable)FormFlow.stack.pop()).show();	}}/* * Design an interface to extract common functionality */package tips.formstack;public interface Showable {	void show();}/* * Design a class that implements Showable*/package tips.formstack;public class MyShowableObject implements Showable {	int index;		public MyShowableObject(int index){		this.index = index;	}			public void show() {		System.out.println("Showing "+index);			}}