structure
Class Table

java.lang.Object
  |
  +--structure.AbstractMap
        |
        +--structure.Table

All Implemented Interfaces:

Map, OrderedMap

public class Table

extends AbstractMap

implements OrderedMap

An implementation of an ordered dictionary. Key-value pairs are kept in the structure in order. To accomplish this, the keys of the table must be comparable.

Example Usage:

To create an alphebetized dictionary by reading a collection of words and definitions from System.in we could use the following:

 public static void main (String[] argv){
 	OrderedMap dict = new Table();
	ReadStream r = new ReadStream();
	String word, def;
	System.out.println("Enter a word: ");
	while(!r.eof()){
	    word = r.readLine();
	    System.out.println("Enter a definition: ");
	    def = r.readLine();
	    dict.put(word,def);
	    System.out.println("Enter a word: ");
	}
	System.out.println(dict);
 }
 

See Also:

Comparable

Field Summary

protected OrderedStructure

data An ordered structure that maintains the ComparableAssociations that store the key-value pairings.

Constructor Summary

Table()
Construct a new, empty table.

Table(Table other)

Method Summary

void	clear() Remove all the elements of the table.
boolean	containsKey(Object key) Determine if the key is in the table.
boolean	containsValue(Object value) Returns true if the value is associated with some key in the table.
Set	entrySet() Return a structure containing all the entries in this Table
Object	get(Object key) Retrieve the value associated with the key provided.
boolean	isEmpty() Determine if the table is empty.
Iterator	iterator() Construct an iterator over the values of the table.
Iterator	keys() Construct an iterator over the keys of the table.
Set	keySet() Return a set containing the keys referenced by this data structure.
static void	main(String[] argv)
Object	put(Object key, Object value) Enter a key-value pair into the table.
Object	remove(Object key) Remove a key-value pair, based on key.
int	size() Determine the number of key-value pairs within the table.
String	toString() Construct a string representing value of table.
Structure	values() Return a structure containing all the values referenced by this data structure.

Methods inherited from class structure.AbstractMap

hashCode, putAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface structure.Map

equals, hashCode, putAll

Field Detail

data

protected OrderedStructure data

An ordered structure that maintains the ComparableAssociations that store the key-value pairings.

Constructor Detail

Table

public Table()

Construct a new, empty table.

Table

public Table(Table other)

Method Detail

get

public Object get(Object key)

Retrieve the value associated with the key provided. Be aware, the value may be null.

Specified by:

get in interface Map

Parameters:

key - The key of the key-value pair sought.

Precondition:

key is a non-null object

Postcondition:

returns value associated with key, or null

Returns:

The value associated with the key.

put

public Object put(Object key,
                  Object value)

Enter a key-value pair into the table. if the key is already in the table, the old value is returned, and the old key-value pair is replaced. Otherwise null is returned. The user is cautioned that a null value returned may indicate there was no prior key-value pair, or --- if null values are inserted --- that the key was previously associated with a null value.

Specified by:

put in interface Map

Parameters:

key - The unique key in the table.

value - The (possibly null) value associated with key.

Precondition:

key is non-null object

Postcondition:

key-value pair is added to table

Returns:

The prior value, or null if no prior value found.

isEmpty

public boolean isEmpty()

Determine if the table is empty.

Specified by:

isEmpty in interface Map

Postcondition:

returns true iff table is empty

Returns:

True iff the table has no elements.

clear

public void clear()

Remove all the elements of the table.

Specified by:

clear in interface Map

Postcondition:

removes all elements from the table

keys

public Iterator keys()

Construct an iterator over the keys of the table. The order of the keys returned is in ascending order. It will be consistent with that of the iterator from elements, provided the table is not modified.

Postcondition:

returns an iterator for traversing keys of table

Returns:

An iterator over the keys of the table.

iterator

public Iterator iterator()

Construct an iterator over the values of the table. The order of the values returned is determined by order of keys. It will be consistent with that of the iterator returned from keys, provided the table is not modified.

Postcondition:

returns an iterator for traversing values in table

Returns:

An iterator over the values of the table.

containsKey

public boolean containsKey(Object key)

Determine if the key is in the table. The key should not be null.

Specified by:

containsKey in interface Map

Parameters:

key - A non-null key sought in the table.

Precondition:

key is non-null object

Postcondition:

returns true iff key indexes a value in table

Returns:

True iff the key is used in association with some value.

containsValue

public boolean containsValue(Object value)

Returns true if the value is associated with some key in the table. This is often difficult to implement efficiently.

Specified by:

containsValue in interface Map

Parameters:

value - The value sought (possibly null).

Precondition:

value is non-null object

Postcondition:

returns true iff value in table

Returns:

True, if the value is associated with some key in table.

remove

public Object remove(Object key)

Remove a key-value pair, based on key. The value is returned.

Specified by:

remove in interface Map

Parameters:

key - The key of the key-value pair to be removed.

Precondition:

key is non-null object

Postcondition:

removes value indexed in table

Returns:

The value associated with key, no longer in table.

size

public int size()

Determine the number of key-value pairs within the table.

Specified by:

size in interface Map

Postcondition:

returns number of key-value pairs in table

Returns:

The number of key-value pairs in the table.

keySet

public Set keySet()

Return a set containing the keys referenced by this data structure.

Specified by:

keySet in interface Map

Postcondition:

Returns a set containing the keys referenced by this data structure.

Returns:

a set containing the key referenced by this data structure.

values

public Structure values()

Return a structure containing all the values referenced by this data structure.

Specified by:

values in interface Map

Postcondition:

Returns a structure containing all the values referenced by this data structure.

Returns:

a structure containing all the values referenced by this data structure.

entrySet

public Set entrySet()

Return a structure containing all the entries in this Table

Specified by:

entrySet in interface Map

Postcondition:

Returns a structure containing all the entries in this Table

Returns:

a structure containing all the entries in this Table

toString

public String toString()

Construct a string representing value of table.

Overrides:

toString in class Object

Postcondition:

returns string representation

Returns:

String representing table.

main

public static void main(String[] argv)