finiteAutomata
Class Association

java.lang.Object
  finiteAutomata.Association

All Implemented Interfaces:

java.util.Map.Entry

public class Association
extends java.lang.Object
implements java.util.Map.Entry

A key-value pair such that the key cannot be modified. Associations are used by the Hashtable class. Adapted from code in "Java Structures: Data Structures in Java for the Principled Programmer", 2nd edition, Duane A. Bailey, 2003 (McGraw-Hill Publishers), p.14.

Version:

Fall 2007

Author:

Barbara Wahl

Field Summary

protected java.lang.Object	theKey the key
protected java.lang.Object	theValue the value

Constructor Summary

Association(java.lang.Object key)
1-parameter constructor.

Association(java.lang.Object key, java.lang.Object value)
2-parameter constructor.

Method Summary

boolean	equals(java.lang.Object other) Tests whether this Association and the given Association have equal keys.
java.lang.Object	getKey() Returns the key.
java.lang.Object	getValue() Returns the value.
static void	main(java.lang.String[] args)
java.lang.Object	setValue(java.lang.Object value) Sets the value of this Association to the given Object.
java.lang.String	toString() Converts this Association to a String for pretty-printing.

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map.Entry

hashCode

Field Detail

theKey

protected java.lang.Object theKey

the key

theValue

protected java.lang.Object theValue

the value

Constructor Detail

Association

public Association(java.lang.Object key,
                   java.lang.Object value)

2-parameter constructor.

Parameters:

key - Object to store as the key

value - Object to store as the value

Precondition:

key is not null

Postcondition:

creates an Association with the given key and value

Association

public Association(java.lang.Object key)

1-parameter constructor.

Parameters:

key - Object to store as the key

Precondition:

key is not null

Postcondition:

creates an Association with the given key and a null value

Method Detail

getKey

public java.lang.Object getKey()

Returns the key.

Specified by:

getKey in interface java.util.Map.Entry

Returns:

Object theKey

getValue

public java.lang.Object getValue()

Returns the value.

Specified by:

getValue in interface java.util.Map.Entry

Returns:

Object theValue (may be null)

toString

public java.lang.String toString()

Converts this Association to a String for pretty-printing.

Overrides:

toString in class java.lang.Object

Returns:

String representation of this Association as an ordered pair (inserts "null" in place of theValue.toString() if the value is null)

setValue

public java.lang.Object setValue(java.lang.Object value)

Sets the value of this Association to the given Object.

Specified by:

setValue in interface java.util.Map.Entry

Parameters:

value - Object to store as the new value

Returns:

(Object) the old value of this Association

equals

public boolean equals(java.lang.Object other)

Tests whether this Association and the given Association have equal keys.

Specified by:

equals in interface java.util.Map.Entry

Overrides:

equals in class java.lang.Object

Parameters:

other - Association to compare with this

Returns:

true iff the two keys are equal, according to the appropriate equals method

Precondition:

other is a non-null Association

main

public static void main(java.lang.String[] args)