1. ./Chicken2.java
2. ./Chicken.java
3. ./DynamicDispatchExample.java
4. ./Rooster2.java
5. ./Rooster.java

/**
 * A simple Java class that models a Chicken. The state of the chicken is its
 * name, height, weight, and gender.
 * 
 * This is the original Chicken class.
 * 
 * @author Sara Sprenkle
 */
public class Chicken2 {

    // ------------ INSTANCE VARIABLES -------------------

    /** the chicken's name */
    private String name;
    
    /** the height of the chicken in centimeters */
    private int height;
    
    /** the weight of the chicken in pounds */
    private double weight;
    
    /** true iff the chicken is a female */
    private boolean isFemale;
    
    public static String DEFAULT_NAME = "BUBBA";

    /**
     * @param name the name of the chicken
     * @param height the height of the chicken in centimeters
     * @param weight the weight of the chicken in pounds
     * @param isFemale whether the chicken is female
     */
    public Chicken2(String name, int height, double weight, boolean isFemale ) {
        this.name = name;
	this.height = height;
	this.weight = weight;
        this.isFemale = isFemale;
    }
    
    /**
    * Assumes Chickens are females
    * @param name the name of the chicken
    * @param height the height of the chicken in centimeters
    * @param weight the weight of the chicken in pounds
    */
    public Chicken2(String name, int height, double weight) {
	this( name, height, weight, true );
    }
    
    /**
     * Default name is Bubba (defined by DEFAULT_NAME)
     * Assumes Chickens are female
     * @param height the height of the chicken in centimeters
     * @param weight the weight of the chicken in pounds
     */
    public Chicken2( int height, double weight ) {
        this( DEFAULT_NAME, height, weight, true);
    }
    
    /**
     * Returns a string representation of the chicken.
     * Format:
     * <br/>Chicken name: &lt;name&gt;
     * <br/>weight: &lt;weight&gt;
     * <br/>height: &lt;height&gt;
     * <br/>female/male
     */
     @Override
     public String toString() {
        StringBuffer rep = new StringBuffer("Chicken name: ");
        rep.append(name);
        rep.append("\nweight: ");
        rep.append(weight);
        rep.append("\nheight: ");
        rep.append(height);
        rep.append("\n");
        rep.append( isFemale? "female" : "male"); // Java ternary operator; also available in C
        return rep.toString();
     }

    /**
     * Determines if two Chickens are equivalent, based on their
     * name, height, weight, and gender.
     */
    @Override
    public boolean equals(Object o) {
        
        if( o == this ) {
            return true;   
        }
        
        Chicken2 other = (Chicken2) o;
        
        if( ! other.getName().equals(this.getName() ) ) {
            return false;
        }
        
        if( other.getHeight() != this.getHeight() ) {
            return false;   
        }
        
        if( other.getWeight() != this.getWeight() ) {
            return false;   
        }
        
        if( this.isFemale() ) {
            return other.isFemale();
        } else {
            return ! other.isFemale();
        }
        
    }
    
    //
    // ----------- GETTER METHODS ------------
    // (also Accessor methods)
    
    /**
     * @return the height of the chicken, in centimeters
     */
    public int getHeight() {
	return height;
    }

    /**
     * @return the weight of the chicken, in pounds
     */
    public double getWeight() {
	return weight;
    }

    /**
     * @return the name of the chicken
     */
    public String getName() {
	return name;
    }
    
    /**
     * @return whether this chicken is female.
     */
    public boolean isFemale() {
        return isFemale;   
    }
    

    //
    // ------------- MUTATORS -----------
    //
    
    /**
     * Feeds the chicken--making the chicken grow
     */
    public void feed() {
	weight += .2;
	height += 1;
    }
	
    //
    // ------------- SETTERS ----------
    //
    
    /**
     * @param n
     *            the name of the chicken
     */
    public void setName(String n) {
	name = n;
    }

    /**
     * @param h
     *            the height of the chicken, in cm
     */
    public void setHeight(int h) {
	height = h;
    }
    
    /**
     * @param w
     *            the weight of the chicken, in pounds
     */
    public void setWeight(double w) {
	weight = w;
    }
    
    /**
     * @param args
     *            the command-line arguments
     */
    public static void main(String args[]) {
	Chicken2 one = new Chicken2("Fred", 38, 2.0, false);
        Chicken2 two = new Chicken2("Sallie Mae", 45, 3.0);
        Chicken2 oneFemale = new Chicken2("Fred", 38, 2.0, true);
        
        System.out.println(one.getName() + " weighs " + one.getWeight() );
        one.feed();
        System.out.println(one.getName() + " ate, so he now weighs " + one.getWeight() );
        
        System.out.print(two.getName() + " is now ");
        two.setName("The Divine Miss Sallie Mae");
        System.out.println(two.getName());
        
        // test toString method
        System.out.println(one);
        
        System.out.println( one + " equal to " + two + "? " + one.equals(two) );
        System.out.println( one + " equal to " + oneFemale + "? " + one.equals(oneFemale) );
        System.out.println( two + " equal to " + two + "? " + two.equals(two) );

	
    }

}

/**
 * A simple Java class that models a Chicken. The state of the chicken is its
 * name, height, weight, and gender.
 * 
 * Keeps instance variables protected, rather than private
 *
 * @author Sara Sprenkle
 */
public class Chicken {

    // ------------ INSTANCE VARIABLES -------------------

    /** the chicken's name */
    protected String name;
	
    /** the height of the chicken in centimeters */
    protected int height;
    
    /** the weight of the chicken in pounds */
    protected double weight;
    
    /** true iff the chicken is a female */
    protected boolean isFemale;
    
    public static String DEFAULT_NAME = "BUBBA";

    /**
     * @param name the name of the chicken
     * @param height the height of the chicken in centimeters
     * @param weight the weight of the chicken in pounds
     * @param isFemale whether the chicken is female
     */
    public Chicken(String name, int height, double weight, boolean isFemale ) {
        this.name = name;
	this.height = height;
	this.weight = weight;
        this.isFemale = isFemale;
    }
    
   /**
    * Assumes Chickens are females
    * @param name the name of the chicken
    * @param height the height of the chicken in centimeters
    * @param weight the weight of the chicken in pounds
    */
    public Chicken(String name, int height, double weight) {
	this( name, height, weight, true );
    }
    
    /**
     * Default name is Bubba (defined by DEFAULT_NAME)
     * Assumes Chickens are female
     * @param height the height of the chicken in centimeters
     * @param weight the weight of the chicken in pounds
     */
    public Chicken( int height, double weight ) {
        this( DEFAULT_NAME, height, weight, true);
    }
    
    /**
     * Returns a string representation of the chicken.
     * Format:
     * <br/>Chicken name: &lt;name&gt;
     * <br/>weight: &lt;weight&gt;
     * <br/>height: &lt;height&gt;
     * <br/>female/male
     */
    @Override
    public String toString() {
        StringBuffer rep = new StringBuffer("Chicken name: ");
        rep.append(name);
        rep.append("\nweight: ");
        rep.append(weight);
        rep.append("\nheight: ");
        rep.append(height);
        rep.append("\n");
        rep.append( isFemale? "female" : "male"); // Java ternary operator; also available in C
        return rep.toString();
    }

    /**
     * Determines if two Chickens are equivalent, based on their
     * name, height, weight, and gender.
     */
     @Override
     public boolean equals(Object o) {
        
        if( o == this ) {
            return true;   
        }
        
        Chicken other = (Chicken) o;
        
        if( ! other.getName().equals(this.getName() ) ) {
            return false;
        }
        
        if( other.getHeight() != this.getHeight() ) {
            return false;   
        }
        
        if( other.getWeight() != this.getWeight() ) {
            return false;   
        }
        
        if( this.isFemale() ) {
            return other.isFemale();
        } else {
            return ! other.isFemale();
        }
        
    }
    
    //
    // ----------- GETTER METHODS ------------
    // (also Accessor methods)

    /**
     * @return the height of the chicken, in centimeters
     */
    public int getHeight() {
	return height;
    }

    /**
     * @return the weight of the chicken, in pounds
     */
    public double getWeight() {
	return weight;
    }

    /**
     * @return the name of the chicken
     */
    public String getName() {
	return name;
    }
    
    /**
     * @return whether this chicken is female.
     */
    public boolean isFemale() {
        return isFemale;   
    }
    

    //
    // ------------- MUTATORS -----------
    //
	
    /**
     * Feeds the chicken--making the chicken grow
     */
    public void feed() {
	weight += .2;
	height += 1;
    }
    
    //
    // ------------- SETTERS ----------
    //
    
    /**
     * @param n
     *            the name of the chicken
     */
    public void setName(String n) {
	name = n;
    }
    
    /**
     * @param h
     *            the height of the chicken, in cm
     */
    public void setHeight(int h) {
	height = h;
    }
    
    /**
     * @param w
     *            the weight of the chicken, in pounds
     */
    public void setWeight(double w) {
	weight = w;
    }
    
    /**
     * @param args
     *            the command-line arguments
     */
    public static void main(String args[]) {
        Chicken one = new Chicken("Fred", 38, 2.0, false);
        Chicken two = new Chicken("Sallie Mae", 45, 3.0);
        Chicken oneFemale = new Chicken("Fred", 38, 2.0, true);
        
        System.out.println(one.getName() + " weighs " + one.getWeight() );
        one.feed();
        System.out.println(one.getName() + " ate, so he now weighs " + one.getWeight() );
        
        System.out.print(two.getName() + " is now ");
        two.setName("The Divine Miss Sallie Mae");
        System.out.println(two.getName());
        
        // test toString method
        System.out.println(one);
        
        System.out.println( one + " equal to " + two + "? " + one.equals(two) );
        System.out.println( one + " equal to " + oneFemale + "? " + one.equals(oneFemale) );
        System.out.println( two + " equal to " + two + "? " + two.equals(two) );

		
    }

}

/**
 * This class demonstrates using dynamic dispatch
 *
 * @author Sara Sprenkle
 *
 */
public class DynamicDispatchExample {  
    
    public static void main(String[] args) {
        Parent p = new Parent();
        Child c = new Child();
        
        p.method1();
        System.out.println("");

        c.method1();
        System.out.println("");
        
        p.method2();
        System.out.println("");

        c.method2();
        System.out.println("");
    }
}

class Parent {
 
    public Parent() {
    }
    
    public void method1() {
        System.out.println("Parent: method1");   
    }
    
    public void method2() {
        System.out.println("Parent: method2");
        method1();
    }
    
}

class Child extends Parent {
 
    public Child() {
    }
    
    public void method1() {
        System.out.println("Child: method1");   
    }
    
}

/**
 * Class represents a rooster.
 * 
 * Example of how to extend a class whose instance variables are *private*.
 * 
 * @author Sara Sprenkle
 */
public class Rooster2 extends Chicken2 {
    
    /**
     * @param name the name of the chicken
     * @param height the height of the chicken in centimeters
     * @param weight the weight of the chicken in pounds
     */
    public Rooster2(String name, int height, double weight) {
	// call to the super constructor must be the first line in constructor
	super(name, height, weight, false);
	// NOTE: reduces amount of code required in Rooster class,
	// increases code reuse, decreases code duplication
    }
    
    // new functionality
    public void crow() {
	System.out.println("Cocka-Doodle-Doo!");
    }
    
    /**
     * overrides superclass; greater gains
     */
    @Override
    public void feed() {
	this.setWeight(this.getWeight() + .5);
	this.setHeight(this.getHeight() + 2);
    }
    
    public static void main(String argv[]) {
	Rooster2 leghorn = new Rooster2("Foghorn", 22, 10);
	System.out.println(leghorn);
	leghorn.crow();
	leghorn.feed();
	System.out.println(leghorn);
    }

}

/**
* Class represents a rooster.
* 
* Example of how to extend a class whose instance variables are *protected*.
* @author Sara Sprenkle
*/
public class Rooster extends Chicken {
    
    /**
     * @param name the name of the chicken
     * @param height the height of the chicken in centimeters
     * @param weight the weight of the chicken in pounds
     */
    public Rooster( String name, int height, double weight ) {
        // call to the super constructor must be the first line in constructor
	super( name, height, weight, false);
        // NOTE: reduces amount of code required in Rooster class,
        // increases code reuse, decreases code duplication
    }

    // new functionality
    public void crow() {
        System.out.println("Cocka-Doodle-Doo!");
    }
    
    // overrides superclass; greater gains
    @Override
    public void feed() {
	weight += .5;
	height += 2;
    }
    
    public static void main(String argv[]) {
        Rooster leghorn = new Rooster("Foghorn", 22, 10 );
        System.out.println(leghorn);
        leghorn.crow();
        leghorn.feed();
        System.out.println(leghorn);
    }

}