HireContract.java

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;

public class HireContract {

	// Initialise the properties of the Hire Contract class

	private String refNo;
	private String customerReference;
	private double priceDaily;
	private Calendar startDate;
	private Calendar endDate;
	private Tent tentHired;

	// Creating Constructor

	public HireContract() {
	}

	// rmoved the EndDate from the constructor as new contracts will most likely
	// not have an end data yet.
	// Also removed the tent because the tent should be set with the "setTent"
	// method
	public HireContract(String refNo, String customerReference,
			double priceDaily, Calendar startDate/*
												 * , Calendar endDate, Tent
												 * tentHired
												 */) {

		this.refNo = refNo;
		this.customerReference = customerReference;
		this.priceDaily = priceDaily;
		this.startDate = startDate;
		// this.endDate = endDate;
		this.endDate = null;
		this.tentHired = null;
	}

	// Creating the get methods for properties

	public String getRefNo() {
		return refNo;
	}

	public String getCustomerReference() {
		return customerReference;
	}

	public double getPriceDaily() {
		return priceDaily;
	}

	public Calendar getStartDate() {
		return startDate;
	}

	public Calendar getEndDate() {
		return endDate;
	}

	public Tent getTentHired() {
		return tentHired;
	}

	// Creating the set methods for properties

	public void setRefNo(String RefNo) {
		this.refNo = RefNo;
	}

	public void setCustomerReference(String customerReference) {
		this.customerReference = customerReference;
	}

	public void setPriceDaily(double priceDaily) {
		this.priceDaily = priceDaily;
	}

	public void setStartDate(Calendar startDate) {
		this.startDate = startDate;
	}

	public void setEndDate(Calendar endDate) {
		this.endDate = endDate;
	}

	public void setTentHired(Tent tentHired) {
		this.tentHired = tentHired;
	}

	// This method should be called when a Contract gets a Tent
	public void setTent(Tent tent) {
		// Assign the tent to a contract
		tentHired = tent;

		// The tent becomes unavailable (false) when the tent is hired.
		tentHired.setAvailable(false);

	}

	// This method should take only one parameter as per assignment and that is
	// the endDate
	public void terminateHire(/* HireContract contract, */Calendar endDate/*
																		 * ,
																		 * Calendar
																		 * startDate
																		 */)/*
																			 * throws
																			 * ParseException
																			 */{

		// Just to be sure that there has been a tent assigned:
		if (tentHired != null) {
			// set the end Date for the contract
			this.endDate = endDate;
			// Return the tent

			tentHired.returnTent(startDate, endDate);
			// the following line is per assignment, but actually unnecessary
			// since the returnTent
			// method (as per assignment) updates the lastReturned date of the
			// tent
			tentHired.setLastReturned(endDate);
		}
	}

	// This method needs to return a double for the cost of the hire
	public/* void */double getTotalCost() {

		long time1 = startDate.getTimeInMillis();
		long time2 = endDate.getTimeInMillis();
		long timeDifference = time2 - time1;
		long convertToDays = timeDifference / 1000 / 60 / 60 / 24;

		// double PriceDaily = getPriceDaily(); // PriceDaily is a field of the
		// class,
		// so it can be accessed directly

		double totalCost = priceDaily * convertToDays;
		// System.out.println("The Total Cost of the Hire is: " + totalCost); //
		// Don't print here, just return the result
		return totalCost;
	}

	// For a better version, see the commented toString method in Tent.java
	@Override
	public String toString() {

		// Create an empty String
		String info = "";
		SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy", Locale.UK); // Set
																				// up
																				// sdf

		if ((refNo != null) && (!refNo.isEmpty())) {
			info += "Contract Number: " + refNo + "\n";
		}
		if ((customerReference != null) && (!customerReference.isEmpty())) {
			info += "Customer Reference: " + customerReference + "\n";
		}
		info += "Daily Price: " + priceDaily;
		if (startDate != null) {
			info += "Start Date of Rent: " + sdf.format(startDate.getTime())
					+ "\n";
		}
		if (endDate != null) {
			info += "End Date of Rent: " + sdf.format(endDate.getTime()) + "\n";
		} else {
			// Special case. End date is not set yet, but start date is
			// this means that the rent contract is ongoing
			if (startDate != null) {
				info += "Currently active. \n";
			}
		}
		if (tentHired != null) {
			info += "Tent Ref.No.: " + tentHired.getRefNo();
		}
		return info;
	}

}

Tent.java

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;

public class Tent {

	// These are the properties of the tent class as seen in the UML diagram

	private String refNo; // changed from RefNo - variables start by convention
							// always with a lowercase letter
	private String model; // changed from Model - variables start by convention
							// always with a lowercase letter
	private int width;
	private int height;
	private int depth;
	private int buildTime;
	private int totalDaysHired;
	private Calendar lastReturned;
	// private String availability;
	private boolean available; // the assignment states "whether" available -
								// best resolved with a boolean
								// name "available" is clearer.
	private HireContract mostRecentContract;

	// Scanner myEndScanner = new Scanner(System.in); // No scanner needed in
	// this class.
	// Input should come from the main program

	// Initialising the Constructor

	public Tent() {
	}

	// Shorthand constructor for a completely new tent (0 days hired &
	// available)
	public Tent(String RefNo, String Model, int width, int height, int depth,
			int buildTime) {
		// call the full constructor below
		this(RefNo, Model, width, height, depth, buildTime, 0, true);
	}

	// Full constructor, fills all necessary parameters.
	public Tent(String RefNo, String Model, int width, int height, int depth,
			int buildTime, int totalDaysHired, boolean available) {

		this.refNo = RefNo;
		this.model = Model;
		this.width = width;
		this.height = height;
		this.depth = depth;
		this.buildTime = buildTime;
		this.totalDaysHired = totalDaysHired;
		this.available = available;
	}

	// The following should not be a constructor, it should be handled by
	// getter/setter methods
	/*
	 * public Tent(Calendar lastReturned, HireContract mostRecentContract) {
	 * 
	 * this.lastReturned = lastReturned; this.mostRecentContract =
	 * mostRecentContract; }
	 */

	// This constructor is unnecessary - no contract when Tent is created

	/*
	 * public Tent(String RefNo, String Model, int width, int height, int depth,
	 * int buildTime, int totalDaysHired, Calendar lastReturned, boolean
	 * availability, HireContract mostRecentContract) {
	 * 
	 * this.RefNo = RefNo; this.Model = Model; this.width = width; this.height =
	 * height; this.depth = depth; this.buildTime = buildTime;
	 * this.totalDaysHired = totalDaysHired; this.lastReturned = lastReturned;
	 * this.availability = availability; this.mostRecentContract =
	 * mostRecentContract; }
	 */

	// Creating the get methods for each of the properties

	public String getRefNo() {
		return refNo;
	}

	public String getModel() {
		return model;
	}

	public int getWidth() {
		return width;
	}

	public int getHeight() {
		return height;
	}

	public int getDepth() {
		return depth;
	}

	public int getBuildTime() {
		return buildTime;
	}

	public int getTotalDaysHired() {
		return totalDaysHired;
	}

	public Calendar lastReturned() {
		return lastReturned;
	}

	public boolean isAvailable() {
		return available;
	}

	public HireContract getMostRecentContract() {
		return mostRecentContract;
	}

	// Creating the set methods for each property

	public void setRefNo(String RefNo) {
		this.refNo = RefNo;
	}

	public void setModel(String Model) {
		this.model = Model;
	}

	public void setWidth(int width) {
		this.width = width;
	}

	public void setHeight(int height) {
		this.height = height;
	}

	public void setDepth(int depth) {
		this.depth = depth;
	}

	public void setBuildTime(int buildTime) {
		this.buildTime = buildTime;
	}

	public void setTotalDaysHired(int totalDaysHired) {
		this.totalDaysHired = totalDaysHired;
	}

	public void setLastReturned(Calendar lastReturned) {
		this.lastReturned = lastReturned;
	}

	public void setAvailable(boolean available) {
		this.available = available;
	}
	
	public void setHireContract(HireContract mostRecentContract) {
		this.mostRecentContract = mostRecentContract;
	}

	// Creating the method for the days hired

	public void addDaysHired(Calendar startDate, Calendar endDate) {

		long startTime = startDate.getTimeInMillis();
		long endTime = endDate.getTimeInMillis();
		long timeDifference = endTime - startTime;
		long daysDiff = timeDifference / 1000 / 60 / 60 / 24;
		// the following is unnecessary since you are inside the class
		// setTotalDaysHired(getTotalDaysHired() + (int)daysDiff);
		totalDaysHired += (int) daysDiff; // that's how to change class fields
											// from inside
	}

	// here you are going wrong.
	// The assignment states that "returnTent" should take 2 parameters
	// start date and end date of hire
	// public void returnTent(HireContract contract, Calendar endDate, Tent
	// Availability) throws ParseException{
	public void returnTent(Calendar startDate, Calendar endDate) {

		// Step 1 - Adjust the dateLastReturned
		lastReturned = endDate;

		// Step2 - Make the tent available again
		available = false;

		// Step 3 - create the days difference and add it to the totalHire
		addDaysHired(startDate, endDate);

		// Forget the code below until ---------------------------------
		// This code is unnecessary.

		// Creates the end date of the tent being hired and makes the tent
		// available for hire again

		/*
		 * SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy",
		 * Locale.ENGLISH.UK);
		 * System.out.println("Enter the end date of the new contract."); String
		 * endInput = myEndScanner.nextLine();
		 * endCal.setTime(sdf.parse(endInput)); String formatPlsWorkGod =
		 * sdf.format(endCal.getTime()); // Set instance to cal
		 * contract.setEndDate(endCal); myEndScanner.close();
		 * 
		 * setLastReturned(endDate); setAvailability("Available");
		 * System.out.println(Availability); //} // Have to update
		 * TotalDaysHired to reflect new hire status //long time1 =
		 * startDate.getTimeInMillis(); //long time2 =
		 * endDate.getTimeInMillis(); //long timeDifference = time2-time1;
		 * //long dayDiff = timeDifference/1000/60/60/24;
		 * //setTotalDaysHired(getTotalDaysHired() + (int)dayDiff);
		 */
		// ------------------------------------------------------------- Forget
		// up to here */
	}

	
	@Override
	public String toString() { // This needs a workover as the
		// assignment says "where applicable"

		// Start by reserving a String 
		String info = "";

		// The if below checks that refNo is not null (i.e. something has
		// already
		// been assigned to it)
		// and that refNo is not empty
		if ((refNo != null) && (!refNo.isEmpty())) {
			info += "RefNo: " + refNo + "\n";
		}
		if ((model != null) && (!model.isEmpty())) {
			info += "Model: " + model + "\n";
		}
		if (width > 0) {
			info += "Width: " + width + "\n";
		}
		if (height > 0) {
			info += "Height: " + height + "\n";
		}
		if (depth > 0) {
			info += "Depth: " + depth + "\n";
		}
		if (buildTime > 0) {
			info += "Time to build: " + buildTime + " minutes\n";
		}
		info += "Total days hired so far: " + totalDaysHired + "\n";
		// There would be a more elegant way for achieving the above
		// with the ternary operator
		// I'll show the code - if you heard about the ternary operator, use it
		// and remove the
		// code above

		info += "The tent is currently "
				+ (available ? "available" : "rented out") + ".\n";

		if (lastReturned != null) {
			SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy", Locale.UK); // Set up sdf
			
			info += "Date last returned: " + sdf.format(lastReturned.getTime()) + "\n";
		}

		if (mostRecentContract != null) {
			info += "Most recent contract Ref: "
					+ mostRecentContract.getRefNo();
		}

		return info;
	}	 

	/*
	 * The method below is the more elegant way of creating the 
	 * toString method.
	 * It uses a StringBuilder to generate the string
	 * StringBuilder is a special class made for strings that need assembly
	 * 
	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();
		// The if below checks that refNo is not null (i.e. something has
		// already been assigned to it)
		// and that refNo is not empty
		if ((refNo != null) && (!refNo.isEmpty())) {
			sb.append("RefNo: " + refNo + "\n");
		}
		if ((model != null) && (!model.isEmpty())) {
			sb.append("Model: " + model + "\n");
		}
		if (width > 0) {
			sb.append("Width: " + width + "\n");
		}
		if (height > 0) {
			sb.append("Height: " + height + "\n");
		}
		if (depth > 0) {
			sb.append("Depth: " + depth + "\n");
		}
		if (buildTime > 0) {
			sb.append("Time to build: " + buildTime + " minutes\n");
		}
		sb.append("Total days hired so far: " + totalDaysHired + "\n");

		sb.append("The tent is currently "
				+ (available ? "available" : "rented out") + ".\n");

		if (lastReturned != null) {
			sb.append("Date last returned: " + lastReturned.toString() + "\n");
		}

		if (mostRecentContract != null) {
			sb.append(info += "Most recent contract Ref: "
					+ mostRecentContract.getRefNo());
		}

		return sb.toString();

	} */

}

useTent.java

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;
import java.util.Scanner;

public class useTent {

	static Scanner keyboard = new Scanner(System.in); // Initialising a scanner

	// static Scanner myScanner = new Scanner(System.in); // One Scanner is
	// enough

	public static void main(String[] args) throws ParseException {

		Tent tent1; // Create instance of Tent
		HireContract contract1; // Create instance of HireContract

		// Calling methods

		tent1 = enterTentDetails();
		displayTentDetails(tent1);
		// enterContractDetails(contract1);
		contract1 = processHire(tent1);
		terminateHireContract(contract1);

	}

	// The enterTentDetails returns a Tent object, and doesn't need one passed
	// in
	public static Tent enterTentDetails() {

		// Let the user know that they will be inputting details

		// Prompt user to enter Ref No.
		System.out.print("Enter the Reference Number of the Tent:  ");
		String refNo = keyboard.nextLine();
		// a.setRefNo(RefNo);

		// Prompt user to enter tent model
		System.out.print("Enter the Model Name of the Tent:  ");
		String model = keyboard.nextLine();
		// a.setModel(Model);

		// Prompt user to enter the width
		System.out.print("Enter the width of the Tent in cm: ");
		int width = keyboard.nextInt();
		// a.setWidth(Width);

		// Prompt user to enter the height
		System.out.print("Enter the height of the Tent in cm: ");
		int height = keyboard.nextInt();
		// a.setHeight(Height);

		// Prompt user to enter the depth
		System.out.print("Enter the depth of the Tent in cm: ");
		int depth = keyboard.nextInt();
		// a.setDepth(Depth);

		// Prompt user to enter the build time
		System.out.print("Enter the Time taken to build the Tent in minutes: ");
		int buildTime = keyboard.nextInt();
		// a.setBuildTime(buildTime);
		keyboard.nextLine();

		// All necessary data acquired, create the tent:
		Tent tent = new Tent(refNo, model, width, height, depth, buildTime);
		return tent;

	}

	// This should not be here as per assignment. This should be done inside the
	// assignment
	/*
	 * public static void enterContractDetails(HireContract a) {
	 * 
	 * // Prompt the user to enter Reference Number
	 * System.out.println("Enter the Reference Number of the Contract."); String
	 * RefNo = keyboard.nextLine(); a.setRefNo(RefNo);
	 * 
	 * // Prompt the user to enter the daily price
	 * System.out.println("Enter the Daily Price for hiring this Tent."); double
	 * priceDaily = keyboard.nextDouble(); a.setPriceDaily(priceDaily); }
	 */

	public static HireContract processHire(Tent tent) throws ParseException {

		// Prompt the user to enter Reference Number
		System.out.print("Enter the Reference Number of the Contract: ");
		String refNo = keyboard.nextLine();
		// a.setRefNo(RefNo);
		// Prompt for a customer number
		System.out.print("Enter the Customer number: ");
		String custNo = keyboard.nextLine();

		// Prompt the user to enter the daily price
		System.out.print("Enter the Daily Price for hiring this Tent:");
		double priceDaily = Double.parseDouble(keyboard.nextLine());

		// a.setPriceDaily(priceDaily);
		// Create instance of calendar
		Calendar cal = Calendar.getInstance();
		SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy", Locale.UK); // Set
																				// up
																				// sdf
		System.out.print("Enter the start date of the new contract: ");
		String plsWork = keyboard.nextLine();
		cal.setTime(sdf.parse(plsWork)); // Sets calendar time to the parsed
											// string

		// String formatPlsWorkGod = sdf.format(cal.getTime());
		// Set instance to cal
		// contract.setStartDate(cal);
		// Don't close a scanner except in Main
		// myScanner.close();

		// Now we have all necessary information, create the contract
		HireContract contract = new HireContract(refNo, custNo, priceDaily, cal);
		// Set the tent to the contract
		contract.setTent(tent);

		tent.setHireContract(contract);

		displayTentDetails(tent);

		return contract;

	}

	public static void terminateHireContract(HireContract contract)
			throws ParseException {

		Calendar cal = Calendar.getInstance();
		SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy", Locale.UK); // Set
																				// up
																				// sdf
		System.out.print("Enter the end date of the contract: ");
		String plsWork = keyboard.nextLine();
		cal.setTime(sdf.parse(plsWork)); // Sets calendar time to the parsed
											// string
		// String formatPlsWorkGod = sdf.format(cal.getTime());
		// Set instance to cal
		contract.setEndDate(cal);
		// myScanner.close();

		// Display the tent status before
		System.out.println("Tent details before contract termination: ");
		displayTentDetails(contract.getTentHired());

		// Trying to link to terminateHire
		contract.terminateHire(cal);
		System.out.println();
		System.out.println("The total cost of the hire is: "
				+ contract.getTotalCost(
						));
		System.out.println();

		System.out.println("Tent details after contract termination: ");
		displayTentDetails(contract.getTentHired());
	}

	public static void displayTentDetails(Tent a) {

		System.out.println("- - - - - - - - - -");
		System.out.println("Tent Details");
		System.out.println("- - - - - - - - - -");
		System.out.println(a.toString());
		System.out.println("- - - - - - - - - -");
	}
}