Enum Class GenericDatabaseConfiguration

java.lang.Object

java.lang.Enum<GenericDatabaseConfiguration>

dimstyl.orm.configuration.GenericDatabaseConfiguration

All Implemented Interfaces:

DatabaseConfiguration, Serializable, AutoCloseable, Comparable<GenericDatabaseConfiguration>, Constable

enum GenericDatabaseConfiguration
extends Enum<GenericDatabaseConfiguration>
implements DatabaseConfiguration

Singleton implementation of DatabaseConfiguration for managing database connections.

This enum provides methods for establishing, retrieving, and closing database connections while supporting multiple database engines such as Derby, SQLite, and H2.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
INSTANCE	The singleton instance of the database configuration.

Field Summary

Fields

Modifier and Type	Field	Description
private Connection	connection	The active database connection.
private DatabaseEngine	databaseEngine	The database engine used for the connection.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	GenericDatabaseConfiguration()

Method Summary

Modifier and Type	Method	Description
private String	buildConnectionString(String databaseName, SqlOperation sqlOperation)	Builds the connection string based on the selected DatabaseEngine and the SqlOperation.
void	close()	Closes the active database connection if it exists.
void	connect(String databaseName, SqlOperation sqlOperation)	Establishes a connection to the specified database.
private void	ensureDirectoryExists(String path)	Ensures that the specified directory exists.
Connection	getConnection()	Retrieves the active database connection.
private boolean	isConnected()	Checks if there is an active database connection.
private void	validateConnection()	Validates whether a connection is active.
static GenericDatabaseConfiguration	valueOf(String name)	Returns the enum constant of this class with the specified name.
static GenericDatabaseConfiguration[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

INSTANCE

public static final GenericDatabaseConfiguration INSTANCE

The singleton instance of the database configuration.

Field Details

databaseEngine

private DatabaseEngine databaseEngine

The database engine used for the connection.

connection

private Connection connection

The active database connection.

Constructor Details

GenericDatabaseConfiguration

private GenericDatabaseConfiguration()

Method Details

values

public static GenericDatabaseConfiguration[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static GenericDatabaseConfiguration valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null

connect

public void connect(String databaseName,
 SqlOperation sqlOperation)
             throws DatabaseConnectionException

Establishes a connection to the specified database.

If the database engine is SQLite, it ensures that the required directory exists. The connection string is built based on the selected DatabaseEngine and the SQL operation.

Specified by:

connect in interface DatabaseConfiguration

Parameters:

databaseName - The name of the database.

sqlOperation - The type of SqlOperation to perform.

Throws:

DatabaseConnectionException - If the connection cannot be established.

close

public void close()
           throws DatabaseConnectionException

Closes the active database connection if it exists.

If the connection is active, it is closed, and resources are released.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface DatabaseConfiguration

Throws:

DatabaseConnectionException - If an error occurs while closing the connection.

getConnection

public Connection getConnection()
                         throws DatabaseConnectionException

Retrieves the active database connection.

If the connection is not established or has been closed, an exception is thrown.

Specified by:

getConnection in interface DatabaseConfiguration

Returns:

The active Connection instance.

Throws:

DatabaseConnectionException - If no active connection is available.

validateConnection

private void validateConnection()
                         throws DatabaseConnectionException

Validates whether a connection is active.

If the connection is not established or has been closed, an exception is thrown.

Throws:

DatabaseConnectionException - If the connection is not available.

isConnected

private boolean isConnected()

Checks if there is an active database connection.

Returns:

true if a valid connection exists, false otherwise.

buildConnectionString

private String buildConnectionString(String databaseName,
 SqlOperation sqlOperation)

Builds the connection string based on the selected DatabaseEngine and the SqlOperation.

• For Derby: The database is stored in the project's /db/derby directory.
• For SQLite: The database is stored in the project's /db/sqlite directory.
• For H2: The database is stored in the project's /db/h2 directory.

Parameters:

databaseName - The name of the database.

sqlOperation - The SqlOperation to determine if database creation is needed.

Returns:

A connection string for the specified database engine.

ensureDirectoryExists

private void ensureDirectoryExists(String path)
                            throws IOException

Ensures that the specified directory exists.

If the directory does not exist, it is created.

Parameters:

path - The directory path to check or create.

Throws:

IOException - If an error occurs while creating the directory.