org.objectweb.cjdbc.controller.backend
Class DatabaseBackendMetaData

java.lang.Object
  org.objectweb.cjdbc.controller.backend.DatabaseBackendMetaData

public final class DatabaseBackendMetaData

extends java.lang.Object

A DatabaseBackendMetaData is used to retrieve the database schema of a real database backend that will have to be bound to a virtual C-JDBC database.

Version:

1.0

Author:

Julie Marguerite , Emmanuel Cecchet , Nicolas Modrzyk , Mathieu Peltier , Jean-Bernard van Zuylen

Field Summary

private AbstractConnectionManager	connectionManager Connection manager to get a connection from.
private DatabaseSchema	databaseSchema Schema of the database backend.
private int	dynamicPrecision The precision of the dynamically generated schema
private boolean	gatherSystemTables Should the system tables be gathered or not
private Trace	logger Logger instance.
private MetadataContainer	metadataContainer Container for static metadata
private java.lang.String	schemaName The name of the schema used to gather meta data

Constructor Summary

DatabaseBackendMetaData(AbstractConnectionManager connectionManager, Trace logger, int dynamicPrecision, boolean gatherSystemTables, java.lang.String schemaName)
Creates a new DatabaseBackendMetaData instance.

Method Summary

void	createDatabaseSchemaDynamically() Gets the list of tables of a database and add them to the database schema.
DatabaseSchema	getDatabaseSchema() Returns the database schema.
private void	insertMetadataInContainer(java.sql.DatabaseMetaData metaData, java.lang.String methodName, java.lang.Class[] parametersType, java.lang.Object[] arguments) This method invokes by reflection the appropriate metadata method and fills the container with the result.
private void	overrideCJDBCSpecificFeatures() This method overrides metdata container information with C-JDBC specific limitations.
MetadataContainer	retrieveDatabaseMetadata() Retrieve metadata from a connection on this backend and build the ("getDataXXX(Y,Z,
private void	updateContainerInformation(java.lang.String methodName, java.lang.Class[] parametersType, java.lang.Object[] arguments, java.lang.Object result) Update the metadata container information for the given method.

Methods inherited from class java.lang.Object

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

Field Detail

connectionManager

private AbstractConnectionManager connectionManager

Connection manager to get a connection from.

logger

private Trace logger

Logger instance.

databaseSchema

private DatabaseSchema databaseSchema

Schema of the database backend.

dynamicPrecision

private int dynamicPrecision

The precision of the dynamically generated schema

gatherSystemTables

private boolean gatherSystemTables

Should the system tables be gathered or not

schemaName

private java.lang.String schemaName

The name of the schema used to gather meta data

metadataContainer

private MetadataContainer metadataContainer

Container for static metadata

Constructor Detail

DatabaseBackendMetaData

public DatabaseBackendMetaData(AbstractConnectionManager connectionManager,
                               Trace logger,
                               int dynamicPrecision,
                               boolean gatherSystemTables,
                               java.lang.String schemaName)

Creates a new DatabaseBackendMetaData instance. This class takes care of initializing the connection manager if needed but the driver must have been previously loaded else the connection manager's initialization will fail.

Parameters:

connectionManager - the connection manager to gather the schema from

logger - the logger (usually the backend logger) to use

dynamicPrecision - the precision with which we gather a schema directly from the backend

gatherSystemTables - true if system tables must be gathered

schemaName - schema name to use to retrieve information

Method Detail

insertMetadataInContainer

private void insertMetadataInContainer(java.sql.DatabaseMetaData metaData,
                                       java.lang.String methodName,
                                       java.lang.Class[] parametersType,
                                       java.lang.Object[] arguments)

This method invokes by reflection the appropriate metadata method and fills the container with the result.

Parameters:

metaData - metadata to invoke

methodName - method to invoke

parametersType - parameters type of method to invoke

arguments - arguments to invoke the method

updateContainerInformation

private void updateContainerInformation(java.lang.String methodName,
                                        java.lang.Class[] parametersType,
                                        java.lang.Object[] arguments,
                                        java.lang.Object result)

Update the metadata container information for the given method.

Parameters:

methodName - method invoked to generate the key in the container

parametersType - parameters type of invoked method

arguments - arguments used to invoke the method

result - result of the method call

retrieveDatabaseMetadata

public MetadataContainer retrieveDatabaseMetadata()
                                           throws java.sql.SQLException

Retrieve metadata from a connection on this backend and build the ("getDataXXX(Y,Z,...)", value) hash table. Note that some values are overriden with C-JDBC specific features (add-ons or limitations).

Returns:

a metadata container including all metadata values

Throws:

java.sql.SQLException - if an error occurs

overrideCJDBCSpecificFeatures

private void overrideCJDBCSpecificFeatures()

This method overrides metdata container information with C-JDBC specific limitations.

createDatabaseSchemaDynamically

public void createDatabaseSchemaDynamically()
                                     throws java.sql.SQLException

Gets the list of tables of a database and add them to the database schema. The caller must ensure that the parameters are not null.

Throws:

java.sql.SQLException - if an error occurs

getDatabaseSchema

public DatabaseSchema getDatabaseSchema()
                                 throws java.sql.SQLException

Returns the database schema. Returns null If an error has occured during the schema generation.

If the schema has not been previously computed, createDatabaseSchemaDynamically()is called.

Returns:

a DatabaseSchema value

Throws:

java.sql.SQLException - if a problem occurs when creating the database schema

See Also:

createDatabaseSchemaDynamically()