Inheritance - Creating a Multilevel Hierarchy

In this lab you will start use Inheritance to create a Creating a Multilevel Hierarchy.

Deliverable

A zipped NetBeans project with 2 classes

• app
• ZipCode
• Address
• Person
• Player
• FootballPlayer
• SoccerPlayer

Classes

Suggestion:

• Use Netbeans to copy your last lab (Lab 06) to a new project called Lab07.
• Close Lab06.
• Work on the new Lab07 project then.

The Person Class

• Uses encapsulation

1. Attributes
   • private String name
   • private Address address

1. Constructors
   • one constructor with no input parameters
     • since it doesn't receive any input values, you need to use the default values below:
       • name - "John Doe"
       • address - use the default constructor of Address
   • one constructor with all (two) parameters
     • one input parameter for each attribute
2. Methods
   • public String toString()
     • returns this object as a String, i.e., make each attribute a String, concatenate all strings and return as one String.
     • toString() is a special method, you will learn more about it in the next lessons
       • it needs to be public
       • it needs to have @override notation (on the line above the method itself). Netbeans will suggest you do it.
   • Get and Set methods
     • public int getName()
     • public void setName(String name)
     • public Address getAddress()
     • public void setAddress(Address address)

The Player Class (with updates from the last lab)

• Player is a Person with some extra attributes
• Uses encapsulation
• Player now is an abstract class because it has an abstract method
  • public double getRatings( );
    • an abstract method is an incomplete method that has to be implemented by the subclasses.

1. Attributes
   • private int number
   • private String sports
   • private gamesPlayed

1. Constructors
   • one constructor with no input parameters
     • since it doesn't receive any input values, you need to use the default values below:
       • number - 0
       • sports - "none"
       • gamesPlayed - 0
   • one constructor with all parameters
     • one input parameter for each attribute
2. Methods
   • public String toString()
     • returns this object as a String, i.e., make each attribute a String, concatenate all strings and return as one String.
     • toString() is a special method, you will learn more about it in the next lessons
       • it needs to be public
       • it needs to have @override notation (on the line above the method itself). Netbeans will suggest you do it.
   • Get and Set methods
     • public int getNumber()
     • public void setNumber(int number)
     • public String getSports()
     • public void setSports(String sports)
     • public int getGamesPlayed()
     • public void setGamesPlayed(int gamesPlayed)
   • public abstract getRatings();

The SoccerPlayer Class

• SoccerPlayer is a Player with some extra attributes
• Uses encapsulation
• SoccerPlayer will implement the method getRatings (an abstract method from the superclass Player)
• toString has to include the result of getRatings() too

1. Attributes
   • private int goals
   • private int yellowCards

1. Constructors
   • one constructor with no input parameters
     • since it doesn't receive any input values, you need to use the default values below:
       • goals - 0
       • yellowCards - 0
   • one constructor with all (two) parameters
     • one input parameter for each attribute
2. Methods
   • public String toString()
     • returns this object as a String, i.e., make each attribute a String, concatenate all strings and return as one String.
     • toString() is a special method, you will learn more about it in the next lessons
       • it needs to be public
       • it needs to have @override notation (on the line above the method itself). Netbeans will suggest you do it.
       • should also include the value of getRatings() in the string
   • Get and Set methods
     • public int getGoals()
     • public void setGoals(int goals)
     • public int getYellowCards()
     • public void setYellowCards(int yellowCards)
   • public double getRatings()
     • calculate and return the rates using this formula:
       • (double) (goals - yellowCards)/gamesPlayed
         • the (double) is called casting, forcing the expression that comes afterwards to become a double.
         • it is necessary to avoid getting 0 as a result because of the precision loss in the division by integers
         • if goals or gamesPlayed is 0, return 0 (you need to do this test to avoid the application crashing in case one of them is 0)

The FootballPlayer Class

• FootballPlayer is a Player with some extra attributes
• Uses encapsulation
• FootballPlayer will implement the method getRatings (an abstract method from the superclass Player)
• toString has to include the result of getRatings() too

1. Attributes
   • private int yards
   • private int minutesPlayed

1. Constructors
   • one constructor with no input parameters
     • since it doesn't receive any input values, you need to use the default values below:
       • yards - 0
       • minutesPlayed - 0
   • one constructor with all (two) parameters
     • one input parameter for each attribute
2. Methods
   • public String toString()
     • returns this object as a String, i.e., make each attribute a String, concatenate all strings and return as one String.
     • toString() is a special method, you will learn more about it in the next lessons
       • it needs to be public
       • it needs to have @override notation (on the line above the method itself). Netbeans will suggest you do it.
       • should also include the value of getRatings() in the string
   • Get and Set methods
     • public int getYards()
     • public void getYards(int yards)
     • public int getMinutesPlayed()
     • public void setMinutesPlayed(int minutesPlayed)
   • public double getRatings()
     • calculate and return the rates using this formula:
       • (double) ( (yards - minutesPlayed/10.0) ) /gamesPlayed
         • be careful with the parenthesis to avoid getting 0 as a result
         • the (double) is called casting, forcing the expression that comes afterwards to become a double.
           • it is necessary to avoid getting 0 as a result because of the precision loss in the division by integers
         • use 10.0 instead of 10 to force Java to use more precision in the calculation
         • if yards or gamesPlayed is 0, return 0 (you need to do this test to avoid the application crashing in case one of them is 0)

App Person Creates a SoccerPlayer object spo using the no-parameter constructor. Creates a Soccer Player object sp1 using the all-parameter constructor. Attributes private String name; private Address address; - Creates a Football Player object fpo using the no-parameter constructor. Creates a Football Player object fp1 using the all-parameter constructor. Constructors No-parameter All-parameter - Using the method toString(), display all the data from each of the 4 objects. Methods String toString() Get/Set methods ZipCode Address . Attributes private String five Digit; private String plus4; Attributes private int number; private String name; private String type; private Zip Code zip; private String state; extends abstract Player Attributes private int number; private String sports; Private int gamesPlayed; Constructors No-parameter One-parameter Two-parameter Constructors No-parameter All-paramet Constructors No-parameter All-parameter Methods String toString() Get/Set methods void display() void display(int p) Methods String toString() Get/Set methods Methods String toString() Get/Set methods abstract double getRatings(); extends Soccer Player Football Player Attributes private int goals; private int yellowCards; Attributes private int yards; private minutesPlayed; Constructors No-parameter All-parameter Constructors No-parameter All-parameter Methods String toString() Get/Set methods double getRatings() Methods String toString() Get/Set methods double getRatings()