nl.cwi.monetdb.embedded.env

Class MonetDBEmbeddedDatabase

java.lang.Object

nl.cwi.monetdb.embedded.env.MonetDBEmbeddedDatabase

public final class MonetDBEmbeddedDatabase
extends Object

An embedded version of a MonetDB database. Communication between Java and native C is done via JNI. The MonetDB's JNI library must be successfully loaded in order to the other methods work.
Note: You can have only one Embedded MonetDB database running per JVM process.

Author:

Pedro Ferreira

Method Summary

Modifier and Type	Method and Description
static MonetDBEmbeddedConnection	createConnection() Creates a connection on the database, set on the default schema.
static JDBCEmbeddedConnection	createJDBCEmbeddedConnection(String directory) Creates a JDBC embedded connection on the database, set on the default schema.
protected void	finalize() Overriding the finalize method to shut down the database.
static String	getDatabaseDirectory() Gets the database's farm directory.
static int	getNumberOfConnections() Gets the current total number of connections to the database.
static boolean	isDatabaseRunning() Check if the database is still running or not.
static boolean	isSequentialFlagSet() Checks if the Sequential Flag was set while creating the database.
static boolean	isSilentFlagSet() Checks if the Silent Flag was set while creating the database.
static void	removeConnection(MonetDBEmbeddedConnection con, boolean toShutDown) Removes a connection from the database.
static void	startDatabase(String dbDirectory, boolean silentFlag, boolean sequentialFlag) Starts a MonetDB database on the given farm.
static void	stopDatabase() Stops the database.

Methods inherited from class java.lang.Object

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

Method Detail

isDatabaseRunning

public static boolean isDatabaseRunning()

Check if the database is still running or not.

Returns:

A boolean indicating if the database is running

startDatabase

public static void startDatabase(String dbDirectory,
                                 boolean silentFlag,
                                 boolean sequentialFlag)
                          throws MonetDBEmbeddedException

Starts a MonetDB database on the given farm.

Parameters:

dbDirectory - The full path of the farm

silentFlag - A boolean if silent mode will be turned on or not

sequentialFlag - A boolean indicating if the sequential pipeline will be set or not

Throws:

MonetDBEmbeddedException - If the JNI library has not been loaded yet or an error in the database occurred

getDatabaseDirectory

public static String getDatabaseDirectory()
                                   throws MonetDBEmbeddedException

Gets the database's farm directory.

Returns:

A String representing the database's farm directory

Throws:

MonetDBEmbeddedException - If the database is not running

getNumberOfConnections

public static int getNumberOfConnections()
                                  throws MonetDBEmbeddedException

Gets the current total number of connections to the database.

Returns:

The total number of connections to the database

Throws:

MonetDBEmbeddedException - If the database is not running

isSilentFlagSet

public static boolean isSilentFlagSet()
                               throws MonetDBEmbeddedException

Checks if the Silent Flag was set while creating the database.

Returns:

The Silent Flag

Throws:

MonetDBEmbeddedException - If the database is not running

isSequentialFlagSet

public static boolean isSequentialFlagSet()
                                   throws MonetDBEmbeddedException

Checks if the Sequential Flag was set while creating the database.

Returns:

The Sequential Flag

Throws:

MonetDBEmbeddedException - If the database is not running

stopDatabase

public static void stopDatabase()
                         throws MonetDBEmbeddedException

Stops the database. All the pending connections will be shut down as well.

Throws:

MonetDBEmbeddedException - If the database is not running or an error in the database occurred

createConnection

public static MonetDBEmbeddedConnection createConnection()
                                                  throws MonetDBEmbeddedException

Creates a connection on the database, set on the default schema.

Returns:

A MonetDBEmbeddedConnection instance

Throws:

MonetDBEmbeddedException - If the database is not running or an error in the database occurred

createJDBCEmbeddedConnection

public static JDBCEmbeddedConnection createJDBCEmbeddedConnection(String directory)
                                                           throws MonetDBEmbeddedException

Creates a JDBC embedded connection on the database, set on the default schema.

Parameters:

directory - The desired directory for the JDBC embedded connection.

Returns:

A JDBCEmbeddedConnection instance

Throws:

MonetDBEmbeddedException - If the database is not running or an error in the database occurred

removeConnection

public static void removeConnection(MonetDBEmbeddedConnection con,
                                    boolean toShutDown)

Removes a connection from the database.

Parameters:

con - The connection to remove

toShutDown - If true, if there are no more connections in the database after the removal, the database is shut down.

finalize

protected void finalize()
                 throws Throwable

Overriding the finalize method to shut down the database. As the MonetDBEmbeddedDatabase is a static variable, it will be garbage collected when the ClassLoader of this class gets Garbage Collected.

Overrides:

finalize in class Object

Throws:

Throwable