tigase.db
Interface DataRepository

All Known Implementing Classes:

DataRepositoryImpl, DataRepositoryPool

public interface DataRepository

The interface defines a generic data repository for storing arbitrary data in any application specific form. This interface unifies database (repository) access allowing for easier way to create database connections pools or database fail-over mechanisms. Created: Jun 16, 2010 3:34:32 PM

Version:

$Rev$

Author:

Artur Hefczyc

Method Summary

boolean	checkTable(String tableName) The method checks whether a table for the given name exists in the database.
boolean	checkTable(String tableName, String createTableQuery) The method checks whether a table for the given name exists in the database and if it does not, it automatically creates it.
void	commit() Commits current transaction on the DataRepository connection.
Statement	createStatement(tigase.xmpp.BareJID user_id) Creates a SQL statement on which SQL queries can be executed later by the higher repository layer.
void	endTransaction() Ends current transaction on the DataRepository connection.
PreparedStatement	getPreparedStatement(tigase.xmpp.BareJID user_id, String stIdKey) Returns a prepared statement for a given key.
String	getResourceUri() Returns a DB connection string or DB connection URI.
void	initPreparedStatement(String stIdKey, String query) Initializes a prepared statement for a given query and stores it internally under the given id key.
void	initRepository(String resource_uri, Map<String,String> params) The method is called to initialize the data repository.
void	release(Statement stmt, ResultSet rs) A helper method to release resources from the statement and result set.
void	releaseRepoHandle(DataRepository repo)
void	rollback() Rolls back started transaction on the DataRepository connection.
void	startTransaction() Starts transaction on the DataRepository connection.
DataRepository	takeRepoHandle(tigase.xmpp.BareJID user_id) Returns DataRepository instance.

Method Detail

checkTable

boolean checkTable(String tableName)
                   throws SQLException

The method checks whether a table for the given name exists in the database.

Parameters:

tableName - is a String value of the table name to check

Returns:

true boolean value if the table exist in the database and false if the table was not found.

Throws:

SQLException - if there was a problem accessing database.

checkTable

boolean checkTable(String tableName,
                   String createTableQuery)
                   throws SQLException

The method checks whether a table for the given name exists in the database and if it does not, it automatically creates it.

Parameters:

tableName - is a String value of the table name to check

createTableQuery - is a String with the query to create table

Returns:

true boolean value if the table exist in the database and false if the table was not found.

Throws:

SQLException - if there was a problem accessing database.

createStatement

Statement createStatement(tigase.xmpp.BareJID user_id)
                          throws SQLException

Creates a SQL statement on which SQL queries can be executed later by the higher repository layer.

Parameters:

A - user id for which the statement has to be created. This is an optional parameter and null can be provided. It is used mainly to group queries for the same user on the same DB connection.

Returns:

a newly created Statement

Throws:

SQLException - if a JDBC error occurs.

getPreparedStatement

PreparedStatement getPreparedStatement(tigase.xmpp.BareJID user_id,
                                       String stIdKey)
                                       throws SQLException

Returns a prepared statement for a given key.

Parameters:

A - user id for which the statement has to be created. This is an optional parameter and null can be provided. It is used mainly to group queries for the same user on the same DB connection.

stIdKey - is a statement identification key.

Returns:

a PreparedStatement for the given id key or null if such a statement does not exist.

Throws:

SQLException

getResourceUri

String getResourceUri()

Returns a DB connection string or DB connection URI.

Returns:

a String value representing database connection string.

initPreparedStatement

void initPreparedStatement(String stIdKey,
                           String query)
                           throws SQLException

Initializes a prepared statement for a given query and stores it internally under the given id key. It can be retrieved later using getPreparedStatement(stIdKey) method.

Parameters:

stIdKey - is a statement identification key.

query - is a query for the prepared statement.

Throws:

SQLException

initRepository

void initRepository(String resource_uri,
                    Map<String,String> params)
                    throws SQLException

The method is called to initialize the data repository. Depending on the implementation all the initialization parameters can be passed either via resource_uri parameter as the database connection string or via params map if the required repository parameters are more complex or both.

Parameters:

resource_uri - value in most cases representing the database connection string.

params - is a Map with repository properties necessary to initialize and perform all the functions. The initialization parameters are implementation dependent.

Throws:

SQLException - if there was an error during repository initialization. Some implementations, though, perform so called lazy initialization so even though there is a problem with the underlying repository it may not be signaled through this method call.

release

void release(Statement stmt,
             ResultSet rs)

A helper method to release resources from the statement and result set. This is most common operation for all database calls, therefore it does make sense to add such a utility method to the API.

Parameters:

stmt - a Statement variable to release resources for. Might be null.

rs - a ResultSet variable to release resources for. Might be null.

takeRepoHandle

DataRepository takeRepoHandle(tigase.xmpp.BareJID user_id)

Returns DataRepository instance. If this is a repository pool then it returns particular instance from the pool. It this is a real repository instance it returns itself. This is exclusive take, no other thread may use this handle until it is returned to the pool.

Parameters:

user_id - is user account ID for which we acquire the handle.

Returns:

DataRepository instance.

releaseRepoHandle

void releaseRepoHandle(DataRepository repo)

startTransaction

void startTransaction()
                      throws SQLException

Starts transaction on the DataRepository connection. Please note that calling this method on the repository pool has no effect. You have to obtain particular repository handle first, before you can start transaction.

Throws:

SQLException

commit

void commit()
            throws SQLException

Commits current transaction on the DataRepository connection. Please note that calling this method on the repository pool has no effect. You have to obtain particular repository handle first, before you can start transaction.

Throws:

SQLException

rollback

void rollback()
              throws SQLException

Rolls back started transaction on the DataRepository connection. Please note that calling this method on the repository pool has no effect. You have to obtain particular repository handle first, before you can start transaction.

Throws:

SQLException

endTransaction

void endTransaction()
                    throws SQLException

Ends current transaction on the DataRepository connection. Please note that calling this method on the repository pool has no effect. You have to obtain particular repository handle first, before you can start transaction.

Throws:

SQLException