com.astroshare.astroonline.database
Class Database

java.lang.Object
  com.astroshare.astroonline.database.Database

Direct Known Subclasses:

Sql

public class Database
extends java.lang.Object

Implementation of the Astro-Online database connection.

The Astro-Online Database object implements connection pooling by default. Connection pooling is supported in two variants:

1. Through class Pool
2. Through JNDI

Whether variant 1 or 2 is used, depends on the value of the node AstroOnlineConfiguration.server.database in the configuration file. If the value is JDNI, variant 2 is used, otherwise variant 1 is used.

Variant 1: Through class Pool

The class Pool is an Astro-Online implementation of a MySQL connection pool. Astro-Online uses this option by default since the value of the node AstroOnlineConfiguration.server.database in the configuration file is POOL by default.

Variant 2: Through JNDI

To use JNDI a connection pool on the web server has to be setup. See the documentation of your the web server for more information on this topic.

Additional information

Astro-Online by default connects to a mysql database. Connecting to other databases should be possible with JNDI but was not tested. It is not possible to connect to other databases with class Pool since this class implicitly implements a connection to MySQL. If an implementation of a pool for another database is necessary, a new pool implementation has to be added and class Database has to be changed to use this implementation.

As a rule of thumb it is best to use the default settings if there runs only one Astro-Online instance on a server. If more than one Astro-Online instance runs on one server, a connection pool can be shared amongst the Astro-Online instances with JNDI. Please, be aware that sharing the connection pool amongst more than one Astro-Online instances means that these instances also share the same tables and therefore use the same configuration table and template table. To give each instance a unique configuration and unique templates, a profile can be added with its own configuration records in the configuration table and its own templates in the templates table. To force an instance to use a specific profile, the node AstroOnlineConfiguration.server.profile in the configuration file has to be modified accordingly. Please read the Astro-Online documentation for more information on the topic.

See Also:

Pool, Sql

Field Summary

protected java.sql.Connection	conn Database connection object
protected static org.apache.log4j.Logger	log init logging

Constructor Summary

Database()
Constructor.

Method Summary

void	close() Close connection.
int	execute(java.lang.String sqlStatement) Execute a SQL DML statement with exception of a SELECT statement (e.q.
java.sql.ResultSet	executeQuery(java.lang.String sqlStatement) Execute SQL SELECT statement.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static org.apache.log4j.Logger log

init logging

conn

protected java.sql.Connection conn

Database connection object

Constructor Detail

Database

public Database()
         throws javax.naming.NamingException,
                java.sql.SQLException

Constructor.

Throws:

javax.naming.NamingException - Exception is thrown when JNDI datasource is not found

java.sql.SQLException - Exception is thrown when a connection cannot be established

Method Detail

close

public void close()

Close connection.

executeQuery

public java.sql.ResultSet executeQuery(java.lang.String sqlStatement)

Execute SQL SELECT statement. Use method execute(java.lang.String) for other SQL DML statements.

Parameters:

sqlStatement - SQL statement

Returns:

Resultset containing the selected records

See Also:

execute(java.lang.String)

execute

public int execute(java.lang.String sqlStatement)

Execute a SQL DML statement with exception of a SELECT statement (e.q. INSERT, UPDATE and DELETE). Use method executeQuery(java.lang.String) for SELECT statements.

Parameters:

sqlStatement - SQL statement

Returns:

-1=An error accured;0=no records effected; >0=number of records effected

See Also:

executeQuery(java.lang.String)