structure
Class ComparableAssociation

java.lang.Object
  |
  +--structure.Association
        |
        +--structure.ComparableAssociation

All Implemented Interfaces:

Comparable, Map.Entry

public class ComparableAssociation

extends Association

implements Comparable

A class implementing a comparable key-value pair. This class associates an immutable key with a mutable value. Useful for many other structures. Example usage:

To print out a list of professors sorted by the number of classes a particular student took from each, we could use the following:

 public static void main(String[] argv){
	//initialize a new fib heap
	FibHeap classesTaken = new FibHeap();

	//add professors and classes taken to a heap
	classesTaken.add(new ComparableAssociation(new Integer(5), "Andrea"));
	classesTaken.add(new ComparableAssociation(new Integer(1), "Barbara"));
	classesTaken.add(new ComparableAssociation(new Integer(3), "Bill"));
	classesTaken.add(new ComparableAssociation(new Integer(2), "Duane"));	
	classesTaken.add(new ComparableAssociation(new Integer(1), "Tom"));	

	//print out classes taken
	while(!classesTaken.isEmpty()){
	    ComparableAssociation p = (ComparableAssociation)classesTaken.remove();
	    System.out.println(p.getValue() + " is " + p.getKey() + " years old.");
	}
 }
 

Fields inherited from class structure.Association

theKey, theValue

Constructor Summary

ComparableAssociation(Comparable key)
Construct an association that can be ordered, from only a key.

ComparableAssociation(Comparable key, Object value)
Construct a key-value association that can be ordered.

Method Summary

int	compareTo(Object other) Determine the order of two comparable associations, based on key.
String	toString() Construct a string representation of the ComparableAssociation.

Methods inherited from class structure.Association

equals, getKey, getValue, hashCode, setValue

Methods inherited from class java.lang.Object

, clone, finalize, getClass, notify, notifyAll, registerNatives, wait, wait, wait

Constructor Detail

ComparableAssociation

public ComparableAssociation(Comparable key)

Construct an association that can be ordered, from only a key. The value is set to null.

Parameters:

key - The (comparable) key.

ComparableAssociation

public ComparableAssociation(Comparable key,
                             Object value)

Construct a key-value association that can be ordered.

Parameters:

key - The (comparable) key.

value - The (possibly comparable) associated value.

Method Detail

compareTo

public int compareTo(Object other)

Determine the order of two comparable associations, based on key.

Specified by:

compareTo in interface Comparable

Parameters:

other - The other comparable association.

Precondition:

other is non-null ComparableAssociation

Postcondition:

returns integer representing relation between values

Returns:

Value less-than equal to or greater than zero based on comparison

toString

public String toString()

Construct a string representation of the ComparableAssociation.

Overrides:

toString in class Association

Postcondition:

returns string representation

Returns:

The string representing the ComparableAssociation.