Contents
- ./Autobox.java
- ./Chicken.java
./Autobox.java 1/2
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/**
* This class demonstrates inefficiencies with unnecessary autoboxing
*
* @author Sara Sprenkle
*/
public class Autobox {
/**
* Called when user runs
* java Autobox
*/
public static void main(String[] args) {
// Find the inefficiency in the code below.
Long sum = 0L;
for (long i=0; i < Integer.MAX_VALUE; i++ ) {
sum += i;
}
System.out.println(sum);
}
}
./Chicken.java 2/2
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/**
* A simple Java class that models a Chicken. The state of the chicken is its
* name, height and weight.
*
* @author Sara Sprenkle
*/
public class Chicken implements Comparable {
// ------------ 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";
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
*/
public Chicken(String name, int height, double weight) {
this( name, height, weight, true );
}
/**
* Default name is Bubba; Assumes Chickens are female
*/
public Chicken( int height, double weight ) {
this( DEFAULT_NAME, height, weight, true);
}
/**
* Returns the chicken's name, weight, and height.
*/
public String toString() {
String rep = "Name: " + name + ", ";
rep += "Weight: " + weight + ", ";
rep += "Height: " + height + ", ";
rep += isFemale ? "female" : "male"; // Java ternary operator; also available in C
return rep;
}
/**
* Determines if two Chickens are equivalent, based on their
* name, height, weight, and gender.
*/
public boolean equals(Object o) {
// o can't be equal if it's not a Chicken
if( ! (o instanceof Chicken) ) {
return false;
}
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();
}
}
@Override
/**
* Compares Chickens based on their height.
* If the other object is not a Chicken, then
* that object is "greater than" this object.
*/
public int compareTo(Object o) {
// Chickens before others
if( ! (o instanceof Chicken) ) {
return -1;
}
Chicken other = (Chicken) o;
if (height < other.getHeight() )
return -1;
if (height > other.getHeight())
return 1;
return 0;
}
//
// ----------- GETTER METHODS ------------
// (also Accessor methods)
/**
* @return the height of the chicken, in centimeters
*/
public int getHeight() {
return height;
}
public double getWeight() {
return weight;
}
public String getName() {
return name;
}
public boolean isFemale() {
return isFemale;
}
//
// ------------- MUTATORS -----------
//
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) );
System.out.println( "Fred vs. Miss Sallie Mae: " + one.compareTo(two) );
System.out.println( "Miss Sallie Mae vs. Fred: " + two.compareTo(one) );
System.out.println( "Fred vs. Female Fred: " + one.compareTo(oneFemale) );
}
}
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