jas.statistics.db
Class Database

java.lang.Object
  jas.statistics.db.Database

All Implemented Interfaces:

ISimEventListener

public class Database
extends java.lang.Object
implements ISimEventListener

A Database object represents a connection with a database management system (natively to a HSQLDB one). It is able to generate creation scripts and to manage multi run data storage.

Title: JAS

Description: Java Agent-based Simulation library

Copyright (C) 2002 Michele Sonnessa

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.

Author:

Michele Sonnessa

Constructor Summary

Database(java.lang.String dbPath, java.lang.String dbName, boolean appendRows)
Create a new database object using the HSQL database driver.

Database(java.lang.String dbDriver, java.lang.String fullConnectionString, java.lang.String dbName, java.lang.String userName, java.lang.String pwd)
Create a new database object using the specified database driver.

Method Summary

CollectionTable	addCollectionTable(java.lang.String name, java.util.Collection collection) Create a new CollectionTable object, using the specified collection, and append it to the table list.
CollectionTable	addCollectionTable(java.lang.String name, int pkMode, java.util.Collection collection) Create a new CollectionTable object, using the specified collection, and append it to the table list.
Table	addTable(java.lang.String name) Create a new Table object and append it to the table list.
Table	addTable(java.lang.String name, int pkMode) Create a new Table object and append it to the table list.
boolean	addTable(Table table) Add a table object to the table list and synchronize it with this database manager.
void	dropDatabaseTables() This method drops the tables currently in the list of tables added with the addTable methods.
int	execute(java.lang.String expression) Execute a SQL command on the database.
java.sql.Connection	getConnection() Return the current connection to the database.
int	getRunId() Return the current number.
Table	getTable(java.lang.String name) Return a table with the given name.
java.util.ArrayList	getTableCachedDataOnDatabase(java.lang.String tableName)
java.util.Collection	getTables() Return the collection of tables added to the database manager.
void	openDatabase() Open the database according to the opening mode specified in the Database constructor.
void	performAction(int actionType) The object implementing this interface is able to receive an event notify.
java.sql.ResultSet	query(java.lang.String expression) Execute a SQL query command on the database and returns a result set.
void	update() Update all the tables.

Methods inherited from class java.lang.Object

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

Constructor Detail

Database

public Database(java.lang.String dbPath,
                java.lang.String dbName,
                boolean appendRows)
         throws java.sql.SQLException

Create a new database object using the HSQL database driver.

Parameters:

dbPath - The absolute path to the database files on disk.

dbName - The name of the database file.

appendRows - False causes the database to be created from scratch. If true the Database object tries to synch the existing database (if it is not existing it creates a new one) and appends the record to the existing tables.

Throws:

java.sql.SQLException - If something goes wrong with the database connection

Database

public Database(java.lang.String dbDriver,
                java.lang.String fullConnectionString,
                java.lang.String dbName,
                java.lang.String userName,
                java.lang.String pwd)
         throws java.sql.SQLException

Create a new database object using the specified database driver. WARNING: The database generation scripts has been designed to fit the HSQL database syntax. Using a different driver may happen some problem. In case the database requires a different script, the user has to override generateCreationStatement() method of the Table object.

Parameters:

dbDriver - The fully qualified name of the java class representing the JDBC driver to be used.

fullConnectionString - The absolute connection string to access the database.

dbName - The name of the database.

userName - The login name to access the database.

pwd - The password for the user name.

Throws:

java.sql.SQLException - If something goes wrong with the database connection

Method Detail

addCollectionTable

public CollectionTable addCollectionTable(java.lang.String name,
                                          java.util.Collection collection)

Create a new CollectionTable object, using the specified collection, and append it to the table list.

Parameters:

name - The name of the table. It must be unique in the database table list.

collection - A Java collection of agents from whose the table collects data.

Returns:

True if the table has been correctly added, false if a table with the same name is already present.

addCollectionTable

public CollectionTable addCollectionTable(java.lang.String name,
                                          int pkMode,
                                          java.util.Collection collection)

Create a new CollectionTable object, using the specified collection, and append it to the table list.

Parameters:

name - The name of the table. It must be unique in the database table list.

collection - A Java collection of agents from whose the table collects data.

Returns:

True if the table has been correctly added, false if a table with the same name is already present.

addTable

public Table addTable(java.lang.String name)

Create a new Table object and append it to the table list.

Parameters:

name - The name of the table. It must be unique in the database table list.

Returns:

True if the table has been correctly added, false if a table with the same name is already present.

addTable

public Table addTable(java.lang.String name,
                      int pkMode)

Create a new Table object and append it to the table list.

Parameters:

name - The name of the table. It must be unique in the database table list.

Returns:

True if the table has been correctly added, false if a table with the same name is already present.

addTable

public boolean addTable(Table table)

Add a table object to the table list and synchronize it with this database manager.

Parameters:

table - A Table object.

Returns:

True if the table has been correctly added, false if a table with the same name is already present.

dropDatabaseTables

public void dropDatabaseTables()
                        throws java.sql.SQLException

This method drops the tables currently in the list of tables added with the addTable methods. If the database contains tables not managed by this object they are left in the database.

Throws:

java.sql.SQLException - If something goes wrong executing the script

execute

public int execute(java.lang.String expression)
            throws java.sql.SQLException

Execute a SQL command on the database.

Parameters:

expression - A SQL script to be executed.

Returns:

The result of the execution script.

Throws:

java.sql.SQLException - If something goes wrong executing the script

getConnection

public java.sql.Connection getConnection()

Return the current connection to the database.

Returns:

A database connection to the current database.

getRunId

public int getRunId()

Return the current number. It is the ID of the RUNS table, used to identify records when the database is open in append mode.

Returns:

The current run id.

getTable

public Table getTable(java.lang.String name)

Return a table with the given name.

Parameters:

name - The name of the table to be found.

Returns:

The table with the given name, null if the table is not present.

getTableCachedDataOnDatabase

public java.util.ArrayList getTableCachedDataOnDatabase(java.lang.String tableName)

getTables

public java.util.Collection getTables()

Return the collection of tables added to the database manager.

Returns:

A collection of tables object.

openDatabase

public void openDatabase()
                  throws java.sql.SQLException

Open the database according to the opening mode specified in the Database constructor. If the Database object has not to append rows, a new database is created generating the creation script. If Database was created with a true value for the appendRow parameter this method tries to synchronize the tables with the existing ones. If new columns have defined they are added to the table. If the existing columns are of a different data type the synching is not possible.

Throws:

java.sql.SQLException - If something goes wrong creating or synching the database

performAction

public void performAction(int actionType)

Description copied from interface: ISimEventListener

The object implementing this interface is able to receive an event notify.

Specified by:

performAction in interface ISimEventListener

Parameters:

actionType - The switch id to select the right action to perform. It might be an Sim.EVENT_* or a custom defined constant.

query

public java.sql.ResultSet query(java.lang.String expression)
                         throws java.sql.SQLException

Execute a SQL query command on the database and returns a result set.

Parameters:

expression - A SQL query script.

Returns:

A ResultSet containing the results of the query, null if the connection is not open.

Throws:

java.sql.SQLException - If something goes wrong executing the script

update

public void update()

Update all the tables.