universe.server.database
Class Database

java.lang.Object
  |
  +--universe.server.database.Database

Direct Known Subclasses:

DatabaseDiskbased

public abstract class Database

extends java.lang.Object

This is the main database class.

Version:

$Id: Database.java,v 1.10 2002/05/19 18:16:21 brianrater Exp $

Author:

Sean Starkey

See Also:

DBItem, Index, Query

Constructor Summary

Database()

Method Summary

abstract void	delete(DBItem item) The delete method is used to remove an item from the database.
abstract DBItem	get(Index index) The get method is used to retrieve specific data from the database.
abstract java.util.Enumeration	query(Query query) The query method is used to retrieve a set of data elements from the database.
abstract void	save() The save method is used to store the current state of the database in permanent storage.
abstract Index	store(DBItem item) The store method is used to change the database.

Methods inherited from class java.lang.Object

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

Constructor Detail

Database

public Database()

Method Detail

store

public abstract Index store(DBItem item)

The store method is used to change the database. Whenever an object (DBItem) is changed, this function must be stored to commit the changes to the database.

get

public abstract DBItem get(Index index)

The get method is used to retrieve specific data from the database. More than likely, the index used is from a query statement.

query

public abstract java.util.Enumeration query(Query query)

The query method is used to retrieve a set of data elements from the database. To get specific information about an individual item, the get method should be used after the Index is found.

delete

public abstract void delete(DBItem item)

The delete method is used to remove an item from the database.

save

public abstract void save()

The save method is used to store the current state of the database in permanent storage.