Package edu.ie3.datamodel.io.connectors

Class SqlConnector

java.lang.Object

edu.ie3.datamodel.io.connectors.SqlConnector

All Implemented Interfaces:

DataConnector

public class SqlConnector
extends Object
implements DataConnector

Implements a DataConnector for a native SQL connection to a relational database. It was implemented with a PostgreSQL database in mind, so there might be dialect issues if used with other databases.

Field Summary

Fields

Modifier and Type	Field	Description
static final org.slf4j.Logger	log

Constructor Summary

Constructors

Constructor	Description
SqlConnector(String jdbcUrl, String userName, String password)	Initializes a SqlConnector with the given JDBC url, username, password and time util

Method Summary

Modifier and Type	Method	Description
ResultSet	executeQuery(Statement stmt, String query)	Executes the given query.
int	executeUpdate(String updateQuery)	Executes an update query
Map<String,String>	extractFieldMap(ResultSet rs)	Extracts only the current row of the ResultSet into a field to value map
List<Map<String,String>>	extractFieldMaps(ResultSet rs)	Extracts all field to value maps from the ResultSet, one for each row
Connection	getConnection()	Establishes and returns a database connection.
Connection	getConnection(boolean reuseConnection)	Establishes and returns a database connection
void	shutdown()

Methods inherited from class java.lang.Object

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

Field Details

log

public static final org.slf4j.Logger log

Constructor Details

SqlConnector

public SqlConnector(String jdbcUrl,
 String userName,
 String password)

Initializes a SqlConnector with the given JDBC url, username, password and time util

Parameters:

jdbcUrl - the JDBC url, should start with "jdbc:postgresql://" and contain the database name

userName - Name of the role used for authentication

password - Password for the role

Method Details

executeQuery

public ResultSet executeQuery(Statement stmt,
 String query)
                       throws SQLException

Executes the given query. For update queries please use executeUpdate(String).

Parameters:

stmt - the created statement

query - the query to execute

Returns:

the query result

Throws:

SQLException - if the execution fails

executeUpdate

public int executeUpdate(String updateQuery)

Executes an update query

Parameters:

updateQuery - the query to execute

Returns:

The number of updates or a negative number if the execution failed

getConnection

public Connection getConnection()
                         throws SQLException

Establishes and returns a database connection. If a connection has not been established yet, a new one is created.

Returns:

the connection object

Throws:

SQLException - if the connection could not be established

getConnection

public Connection getConnection(boolean reuseConnection)
                         throws SQLException

Establishes and returns a database connection

Parameters:

reuseConnection - should the connection be used again, if it is still valid? If not, a new connection will be established

Returns:

the connection object

Throws:

SQLException - if the connection could not be established

shutdown

public void shutdown()

Specified by:

shutdown in interface DataConnector

extractFieldMaps

public List<Map<String,String>> extractFieldMaps(ResultSet rs)

Extracts all field to value maps from the ResultSet, one for each row

Parameters:

rs - the ResultSet to use

Returns:

a list of field maps

extractFieldMap

public Map<String,String> extractFieldMap(ResultSet rs)

Extracts only the current row of the ResultSet into a field to value map

Parameters:

rs - the ResultSet to use

Returns:

the field map for the current row