Thread: Inheritance; Problem with Test class

Hello Everyone, everything has been going good with the whole JAVA learning process until today. I have been working on Inheritance and have not been able to complete this project.
My problem is coming from the test class, I simply do not know how to set it up to output the proper information. So first I have to create a Date class, then a Phone class which is the parent of the CellPhone class and LandLinePhone class. I then have to create a test class called PhoneTest. Everything has been completed except for the PhoneTest class which is the one that outputs everything. Thanks for looking at my issue, hopefully someone can point me in the correct direction.

First I need to develop the classes according to the UML Provide (ill attach a picture of the UML for a visual representation)

in the PhoneTest class the main method created the two dimensional string array, calls createPhones, calculates the monthly charge, and calls printBill

The Method printBill prints the information for each instance to the system prompt.

(along with the UML attachment I will also attach the instruction page of the program for better understanding of what I need to do.

-----Here are my current programs-------

public class Date
{
	private int month;
	private int day;
	private int year;
 
	public Date ()
	{
		setMonth (0);
		setDay (0);
		setYear (0);
 
	}
 
	public Date (int m, int d, int y)
	{
		setMonth (m);
		setDay (d);
		setYear (y);
	}
 
	public void setMonth (int m)
	{
		month = m;
	}
 
	public int getMonth ()
	{
		return month;
	}
 
	public void setDay (int d)
	{
		day =d;
	}
 
	public int getDay()
	{
		return day;
	}
 
	public void setYear (int y)
	{
		year =y;
	}
 
	public int getYear ()
	{
		return year;
	}
 
	public String toString()
	{
		return ("Month" + month +
			"Day" + day +
			"Year" + year);
	}
}

public class Phone
{
	private String brand;
	private String phoneNumber;
	private double monthlyCharge;
	private Date billDate;
 
 
	public Phone ()
	{
		setBrand ("");
		setPhoneNumber ("");
		setMonthlyCharge (0.0);
		setBillDate (new Date () );
	}
 
	public Phone (String b, String pn, double mc, Date bd)
	{
		setBrand ( b );
		setPhoneNumber (pn);
		setMonthlyCharge (mc);
		setBillDate (bd);
	}
 
	public void setBillDate (Date bd)
	{
		billDate = bd;
	}
 
	public Date getBillDate()
	{
		return billDate;
	}
 
	public void setBrand ( String B) 
	{
		brand = b;
	}
 
	public String getBrand ()
	{
		return brand;
	}
 
	public void setPhoneNumber ( String pn )
	{
		phoneNumber = pn;
	}
 
	public String getPhoneNumber ()
	{
		return phoneNumber;
	}
 
	public void setMonthlyCharge (double mc)
	{
		monthlyCharge = mc;
	}
 
	public double getMonthlyCharge ()
	{
		return monthlyCharge;
	}
 
	public String toString ()
	{
		return ("Brand" + brand + 
			 "Phone Number" + phoneNumber +
			 "Monthly Charge" + monthlyCharge +
			  billDate.toString () );
	}
 
	public void calculateMonthlyCharge ()
	{
		setMonthlyCharge(12.0);
	}
}

public class CellPhone extends Phone
{
	private double pricePerMinute;
	private int minutesUsed;
 
	public CellPhone ()
	{
		super();
		setPricePerMinute(0.0);
		setMinutesUsed (0);
	}
 
	public CellPhone (String b, String pn, double mc, Date bd, double ppm,int mu)
	{
		super (b, pn, mc, bd);
		setPricePerMinute(ppm);
		setMinutesUsed (mu);
	}
 
	public void setPricePerMinute (double ppm)
	{
		pricePerMinute = ppm;
	}
 
	public double getPricePerMinute ()
	{
		return pricePerMinute;
	}
 
	public void setMinutesUsed (int mu)
	{
		minutesUsed = mu;
	}
 
	public int getMinutesUsed()
	{
		return minutesUsed;
	}
 
	public String toString()
	{
		return (super.toString() + 
			"Price Per Minute " + pricePerMinute +
			"Minutes Used " + minutesUsed);
	}
 
	public void calculateMonthlyCharge()
	{
		super.calculateMonthlyCharge();
 
		setMonthlyCharge (pricePerMinute * minutesUsed + super.getMonthlyCharge());
	}
}

 
public class LandLinePhone extends Phone
{
	private double longDistanceFee;
	private int longDistanceMinutes;
 
	public LandLinePhone()
	{
		super();
		setLongDistanceFee(0.0);
		setLongDistanceMinutes(0);
	}
 
	public LandLinePhone (String b, String pn, double mc, Date bd, double ldf, int ldm)
	{
		super(b, pn, mc, bd);
		setLongDistanceFee(ldf);
		setLongDistanceMinutes(ldm);
	}
 
	public void setLongDistanceFee(double ldf)
	{
		longDistanceFee = ldf;
	}
 
	public double getLongDistanceFee ()
	{
 
		return longDistanceFee;
	}
 
	public void setLongDistanceMinutes (int ldm)
	{
		longDistanceMinutes = ldm;
	}
 
	public int getLongDistanceMinutes ()
	{
		return longDistanceMinutes;
	}
 
	public String toString()
	{
		return (super.toString() +
			 "Long Distance Fee" + longDistanceFee +
			 "Long Distance Minutes" + longDistanceMinutes);
	}
 
	public void calculateMonthlyCharge()
	{
		super.calculateMonthlyCharge();
 
		setMonthlyCharge (longDistanceFee + super.getMonthlyCharge());
 
	}
}

public class PhoneTest
{
	public static void main (String args [])
	{
 
		double total;
 
		String d[][] = { {"Cell", "Samsung", "817-272-1234", "3/31/2012", "0.6", "750"},
				 {"Land", "Apple", "817-272-4567", "3","15","2012", "9.25", "300"},
				 {"Land", "Verizon", "817-272-9886", "4","1","2012", "12.60", "1125"},
				 {"Cell", "LG", "817-272-6283", "4","15","2012", ".035", "250"} };
 
		Phone myPhones [] = new Phone [4];
 
		myPhones = createPhones(d);
 
		System.out.println (myPhones);
 
		//calls createPhones
 
		//calculates the monthly charge
 
		// calls printBill
 
 
	}
 
	public Phone[] createPhones(String d[][])
	{
 
		Phone myPhones[] = new Phone [d.length];
 
		for (int i = 0; i < d.length; i++)
		{
 
			if (d[i][0].equals("CellPhone"))
 
				myPhones [i] = new CellPhone (d[i][1], d[i][2], 
						   	     new Date (Integer.parseInt(d[i][3])),
						   	     Double.parseDouble(d[i][4]),
						  	     Integer.parseInt(d[i][5]) );
			else
 
				myPhones [i] = new LandLinePhone (d[i][1], d[i][2], 
						       	         new Date (Integer.parseInt(d[i][3])),
						      	         Double.parseDouble(d[i][4]),
						      	         Integer.parseInt(d[i][5]) );
 
			//need help as of what would go in here
			//Something is still wrong with myPhones
 
 
		}
	}
 
	public void printBill (Phone p[])
	{
		//need help as of what goes here
	}
 
}

Screen shot 2012-04-05 at 3.24.17 PM.jpg

Screen shot 2012-04-05 at 3.24.25 PM.jpg

There are a few problems in you createPhones method:

1) You String array does not contain "CellPhone" which is used in your logic test. This will then default to always creating a new LandLinePhone.
2) The number/type of arguments pass in new CellPhone and new LandLinePhone do not match the respective constructors.
2.1) The new Date() format also does not conform to the constructor. You only give one int value instead of three.

If you can get those things worked out then you can check to see if the values are correct by outputting the value of the toString() method for each Phone. After you get that then I would move on to the printBill method.

Got it I made the changes needed. Thanks alot for your input, I''ll post my PhoneTest class to see if my changes are correct in regards to your response.

public class PhoneTest
{
	public static void main (String args [])
	{
 
		double total;
 
		String d[][] = { {"Cell", "Samsung", "817-272-1234", "3","31","2012", "0.6", "750"},
				 {"Land", "Apple", "817-272-4567", "3","15","2012", "9.25", "300"},
				 {"Land", "Verizon", "817-272-9886", "4","1","2012", "12.60", "1125"},
				 {"Cell", "LG", "817-272-6283", "4","15","2012", ".035", "250"} };
 
		Phone myPhones [] = new Phone [4];
 
		myPhones = createPhones(d);
 
		System.out.println (myPhones);
 
		//calls createPhones
 
		//calculates the monthly charge
 
		// calls printBill
 
 
	}
 
	public Phone[] createPhones(String d[][])
	{
 
		Phone myPhones[] = new Phone [d.length];
 
		for (int i = 0; i < d.length; i++)
		{
 
			if (d[i][0].equals("Cell"))
 
				myPhones [i] = new CellPhone (d[i][1], d[i][2], 
						   	     new Date (Integer.parseInt(d[i][3])),
						   	     new Date (Integer.parseInt(d[i][4])),
						   	     new Date (Integer.parseInt(d[i][5])),
						   	     Double.parseDouble(d[i][6]),
						  	     Integer.parseInt(d[i][7]) );
			else
 
				myPhones [i] = new LandLinePhone (d[i][1], d[i][2], 
						       	         new Date (Integer.parseInt(d[i][3])),
						   	     	 new Date (Integer.parseInt(d[i][4])),
						   	     	 new Date (Integer.parseInt(d[i][5])),
							         Double.parseDouble(d[i][6]),
						      	         Integer.parseInt(d[i][7]) );
 
			//need help as of what would go in here
			//Something is still wrong with myPhones
 
 
		}
	}
 
	public void printBill (Phone p[])
	{
		//need help as of what goes here
	}
 
}

4 Things left to adjust for it to work out.

1) The last row in your array has duplicate values (an extra "4").
2) The for loop is just about right, but myPhones is not an array of CellPhone but rather Phone.
3) You will also want to call the toString() method of the Phone object and not the array, in this case 'm'.
4) The createPhones method states that it will return Phone[], but there isn't any return statement in the method. The good news is that you create a Phone[] in your method called myPhones; return that and all is well.

Remember to always ensure that if a method is supposed to return something then there should be a return statement.

Ok i finally got some output back:
I made this change

for (Phone m:myPhones)
		{
			System.out.println(m.toString());
		}

Wonderful, glad to see things are coming together for you. Now that you are able to iterate through each Phone object successfully, the rest is a matter of calling the class methods and formatting the output as described in the Instructions (which is so small it's practically impossible to read).

Awesome, now in regards to printBill, thats the one thats going to print all the information in the way the requirements requires me to do correct?

Thank you, in regards to printBill, this is the part that will output the Type, Minutes, monthly charge and the bill date. Where Type is the type of phone (cell or land line), Minutes is minutes used (only for cell phone),
$xxx.xx is the monthly charge, and x/x/xxxx is the bill date.

So is the for loop suppose to be in printBill instead of the main method?

The loop could be in either, just depends on what you want. You can either pass a single Phone object in the printBill method or the whole Phone array in which case a loop would be needed in printBill.

Yes, what I am trying to do is for Method printBill prints the the information for each instance to the system prompt as follows:

Type Minutes $xxx.xx x/x/xxxx
Type $xxx.xx x/x/xxxx
Type $xxx.xx x/x/xxxx
Type Minutes $xxx.xx x/x/xxxx
Total $xxx.xx

** Where Type is the type of phone (cell or land line), Minutes is minutes used (only for cell phone),
$xxx.xx is the monthly charge, and x/x/xxxx is the bill date.

then the main method calls printBill

So what is your specific problem at this point? Looking at your instructions again it would seem the loop would go in the printBill method.

So like something like this?

public static void printBill (Phone p[])
{
 
		for (Phone m:myPhones)
		{
 
 
		}
 
 
 
		//need help as of what goes here
 
 
	}
 
}

Honestly I have no idea as of how to even start this one. It sucks.

Since you need to print data, look at your classes to see what method returns a String value containing all the information. Your for loop isn't quite right, remember that the Phone array used by the method is 'p'. Finding the total is a matter of adding the specific instance variable of each Phone i.e. total += m.getVariable.

Ok, dang feels like I am lost here, its a bad feeling, sorry for the dumb headed mistakes.
But, is this somewhere along the right direction?

public class PhoneTest
{
	public static void main (String args [])
	{
 
		double total;
 
		String d[][] = { {"Cell", "Samsung", "817-272-1234", "0", "3","31","2012", "0.6", "750"},
				 {"Land", "Apple", "817-272-4567", "0", "3","15","2012", "9.25", "300"},
				 {"Land", "Verizon", "817-272-9886", "0", "4","1","2012", "12.60", "1125"},
				 {"Cell", "LG", "817-272-6283","0","4", "15","2012", ".035", "250"} };
 
		Phone myPhones [] = createPhones(d);
 
 
 
		for (Phone m:myPhones)
		{
			System.out.println( m.toString());
 
			printBill(CellPhone);
 
		}
 
 
 
 
		//calculates the monthly charge
 
		// calls printBill
 
 
	}
 
	public static Phone[] createPhones(String d[][])
	{
 
		Phone myPhones[] = new Phone [d.length];
 
		for (int i = 0; i < d.length; i++)
		{
 
			if (d[i][0].equals("Cell"))
 
				myPhones [i] = new CellPhone (d[i][1], d[i][2], Double.parseDouble(d[i][3]),
						   	     new Date (Integer.parseInt(d[i][4]), Integer.parseInt(d[i][5]), Integer.parseInt(d[i][6])),
						   	     Double.parseDouble(d[i][7]),
						  	     Integer.parseInt(d[i][8]) );
			else
 
				myPhones [i] = new LandLinePhone (d[i][1], d[i][2], Double.parseDouble(d[i][3]),
						   	     	 new Date (Integer.parseInt(d[i][4]), Integer.parseInt(d[i][5]), Integer.parseInt(d[i][6])),
						   	     	 Double.parseDouble(d[i][7]),
						  	     	 Integer.parseInt(d[i][8]) );
 
 
		}
 
		return myPhones;
 
	}
 
	public static void printBill (Phone p[])
	{
 
		for (Phone p:myPhones)
		{
 
			System.out.println (p.toString);
 
                      total+= m.getMonthlyCharge;
 
 
		}
 
 
 
 
	}
 
}