foo.java

/**
 *  A Java program that creates and displays a list of lists
 */
//import java.io.InputStream;
import java.util.Scanner;
/**
 * @author elena
 *
 */
public class Foo {
	
	private static Scanner scanner = new Scanner( System.in ); // Scanner variable to handle user input
	private static GList<InnerList> big_list = new GList<InnerList>(); // GList to hold InnerLists
	private static int value_count = 0; // Count of values to insert into an GList (of an InnerList)
	private static int list_count = 0; // Count of the number of InnerLists
	private static String input2; // Another Scanner variable to handle user input
	
	public static void main(String[] args) {
		
		// Initial call to createList() method
		createList();
	}
	
	public static void createList() {
		// Prompt the user
		System.out.print( "add a list (y/n)? " );
		
		// Read a line of text from the user.
		String input = scanner.nextLine();
		
		// Create a new list
		if (input.compareTo("y") == 0 || input.compareTo("n") == 0) {
			if (input.compareTo("y") == 0) {
				System.out.print( "name of list? " );
				String list_name = scanner.nextLine();
				InnerList inner_list = new InnerList(); // Create a new InnerList
				GList<Integer> g_list = new GList<Integer>(); // Create a new GList to associate with InnerList
				inner_list.setName(list_name);
				insertNumber(inner_list, g_list); // Call insertNumber(), allow user to insert numbers into list
			}
			
			// Print and exit if user doesn't want to create a new list
			else if (input.compareTo("n") == 0) {
				if (list_count >= 1) {
					printList(); // Call print method
				}
				
				//Simply exit if user didn't create a list and notify user
				System.out.println("Exiting..."); 
				System.exit(0);
			}
		}
		else {
			
			// Error check the input
			System.out.println( "please type \"y\" or \"n\"" );
			createList();
		}
	}
	
	// D.R.Y method to insert values into an InnerList
	public static void insertNumber(InnerList inner_list, GList<Integer> g_list) {
		
		// Prompt the user
		System.out.print( "add a number (y/n)? " );
		
		// Read a line of text from the user.
		input2 = scanner.nextLine();
		
		// Insert value into (the GLists inside) InnerLists
		if (input2.compareTo("y") == 0 || input2.compareTo("n") == 0) {
			if (input2.compareTo("y") == 0) {
				
				// Prompt the user
				System.out.print( "value: " );
				Scanner v = new Scanner(System.in);//.nextLine();
				Integer value = Integer.parseInt(v.nextLine().trim());
				
				// If no values were previously added to g_list, use insertFirst() method to insert into g_list
				if (value_count == 0) {
					g_list.insertFirst(value);
					//System.out.println(g_list.getFirstItem());
					inner_list.setInner(g_list);
					value_count++;
				}
				
				// If values were previously added to g_list, use insertNext() method to insert into g_list
				else {
					g_list.insertNext(value);
					inner_list.setInner(g_list);
					value_count++;
				}

				// Call insertNumber() method again, ask user if they want to insert another list
				insertNumber(inner_list, g_list);
			}
			else if (input2.compareTo("n") == 0) {
				if (list_count == 0) {
					big_list.insertFirst(inner_list); // User is done with list, commit InnerList to big list at head
				}
				else {
					big_list.insertNext(inner_list); // User is done with list, commit InnerList to big list after head
				}
				list_count++; // increment list count variable
				value_count = 0;
				createList();
			}	
		}
		else {
			System.out.println( "please type \"y\" or \"n\"" );
			insertNumber(inner_list, g_list);
		}
	}
	
	// Print the list(s)
	public static void printList() {
		
		// Print the list count if a list was created
		if (list_count == 1 ) {
			System.out.println("You created " + list_count + " list.");
		}
		else {
			System.out.println("You created " + list_count + " lists.");
		}
		
		// Print the list name and values only if a list was created
				
		//System.out.println(big_list.);

		// Print the first InnerList's values if there is a first InnerList
		if (big_list.getFirstItem() != null) {
			
			System.out.println("list name: " + big_list.getFirstItem().getName());
			if (big_list.getFirstItem().getInner().getFirstItem() != null) {
				System.out.println(big_list.getFirstItem().getInner().getFirstItem());
			}
			
			while (big_list.getFirstItem().getInner().hasNextItem()){
				System.out.println(big_list.getFirstItem().getInner().getNextItem());
			}
			
			while (big_list.hasNextItem()) {
				System.out.println("list name: " + big_list.getNextItem().getName());
				
				if (big_list.getNextItem().getInner().getFirstItem() != null) {
					System.out.println(big_list.getNextItem().getInner().getFirstItem()); 
				}
					
				//System.out.println(big_list.getFirstItem().getInner().getNextItem());
				//if (big_list.getFirstItem().getInner().getFirstItem() !=) {
					//System.out.println(big_list.getNextItem().getInner().getFirstItem());
					//while(big_list.getNextItem().getInner().hasNextItem()) {
					//	System.out.println(big_list.getNextItem().getInner().getNextItem());
					//}
				}
			
			/*
			if (big_list.hasNextItem()) {
				if (big_list.getNextItem().getInner().getNextItem() == null) {
					System.out.println("It's null!");
				}
			}
			
			
			// Keep printing InnerList names and values if there are more
			
			while (big_list.getNextItem() != null) {
				System.out.println("list name: " + big_list.getNextItem().getName());
				System.out.println(big_list.getNextItem().getInner().getNextItem());
				
				while (big_list.getNextItem().getInner().hasNextItem()){
					System.out.println(big_list.getNextItem().getInner().getNextItem());
				} 
			} */
		}
	}	
}