org.dftproject.genesis.core.data
Class DataConnection

java.lang.Object
  org.dftproject.genesis.core.data.DataConnection

public class DataConnection
extends java.lang.Object

DataConnection wraps a JDBC connection to the underlying database.

Constructor Summary

DataConnection(java.sql.Connection conn, java.lang.String store)
Creates a wrapper for the JDBC connection which can manipulate the given store.

Method Summary

void	close() Closes the underlying JDBC connection.
void	createStore() Creates the current store.
void	delete(INode graph, INode subject, INode predicate, INode object) Deletes the given statement from the current store.
protected void	deleteStatement(java.lang.String graph, java.lang.String subject, java.lang.String predicate, java.lang.String object) Internal method which deletes the raw values of a statement from the current store.
void	deleteStore() Drops all tables, indexes, procedures, and triggers related to the current store from the database.
protected java.lang.String	escape(java.lang.String str) Escapes the given string for use in database queries.
protected void	executeNoErrorHandling(java.lang.String sql) Executes the given SQL statement.
java.sql.ResultSet	executeQuery(java.lang.String sql) Executes the given SQL query.
int	executeUpdate(java.lang.String sql) Executes the given SQL update statement.
protected long	getLongLiteralID(java.lang.String value, boolean add) Returns the ID of the given long literal.
java.lang.String	getLongLiteralTableName() Returns the name of the long literal table for the current store.
protected java.lang.String	getLongLiteralValue(long id) Returns the raw long literal value associated with the ID.
java.lang.String	getStatementTableName() Returns the name of the statement table for the current store.
protected java.lang.String	getWhereClause(java.lang.String graph, java.lang.String subject, java.lang.String predicate, java.lang.String object) Returns a SQL WHERE clause that matches the given raw statement values (non-null parameters).
static void	handleDelete(java.lang.String graph, java.lang.String subject, java.lang.String predicate, java.lang.String object) Called by the statement table deletion trigger to notify listeners.
static void	handleInsert(java.lang.String graph, java.lang.String subject, java.lang.String predicate, java.lang.String object) Called by the statement table insertion trigger to notify listeners.
protected void	initEscape() Initializes the regular expression pattern and replacement string used for escaping database strings.
void	insert(INode graph, INode subject, INode predicate, INode object) Inserts the given statement into the current store.
protected void	insertStatement(java.lang.String graph, java.lang.String subject, java.lang.String predicate, java.lang.String object) Internal method which inserts the raw values of a statement into the current store.
java.lang.String	nodeToString(INode node, boolean addIfLong) Returns the raw database representation of the given node.
boolean	storeExists() Returns whether or not the current store exists.
INode	stringToNode(java.lang.String value, DataView view) Instantiates the node given by the raw database representation.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataConnection

public DataConnection(java.sql.Connection conn,
                      java.lang.String store)

Creates a wrapper for the JDBC connection which can manipulate the given store.

Parameters:

conn - an open JDBC connection

store - the store that this connection manipulates

Method Detail

close

public void close()

Closes the underlying JDBC connection.

initEscape

protected void initEscape()

Initializes the regular expression pattern and replacement string used for escaping database strings.

escape

protected java.lang.String escape(java.lang.String str)

Escapes the given string for use in database queries.

Parameters:

str - the string to escape

Returns:

the escaped string

getStatementTableName

public java.lang.String getStatementTableName()

Returns the name of the statement table for the current store.

Returns:

the name of the statement table

getLongLiteralTableName

public java.lang.String getLongLiteralTableName()

Returns the name of the long literal table for the current store.

The long literal table is used for storing literals whose raw database representation is too large to fit in the statement table.

Returns:

the name of the long literal table

storeExists

public boolean storeExists()
                    throws java.sql.SQLException

Returns whether or not the current store exists.

Returns:

whether or not the current store exists

Throws:

java.sql.SQLException

createStore

public void createStore()
                 throws java.sql.SQLException

Creates the current store.

The name of the store will be used as a table prefix.

Throws:

java.sql.SQLException

deleteStore

public void deleteStore()
                 throws java.sql.SQLException

Drops all tables, indexes, procedures, and triggers related to the current store from the database.

Throws:

java.sql.SQLException

insert

public void insert(INode graph,
                   INode subject,
                   INode predicate,
                   INode object)

Inserts the given statement into the current store.

Parameters:

graph - the graph

subject - the subject

predicate - the predicate

object - the object

insertStatement

protected void insertStatement(java.lang.String graph,
                               java.lang.String subject,
                               java.lang.String predicate,
                               java.lang.String object)

Internal method which inserts the raw values of a statement into the current store.

Parameters:

graph - the graph

subject - the subject

predicate - the predicate

object - the object

delete

public void delete(INode graph,
                   INode subject,
                   INode predicate,
                   INode object)
            throws java.sql.SQLException

Deletes the given statement from the current store.

Parameters:

graph - the graph

subject - the subject

predicate - the predicate

object - the object

Throws:

java.sql.SQLException

deleteStatement

protected void deleteStatement(java.lang.String graph,
                               java.lang.String subject,
                               java.lang.String predicate,
                               java.lang.String object)
                        throws java.sql.SQLException

Internal method which deletes the raw values of a statement from the current store.

Parameters:

graph - the graph

subject - the subject

predicate - the predicate

object - the object

Throws:

java.sql.SQLException

getLongLiteralValue

protected java.lang.String getLongLiteralValue(long id)

Returns the raw long literal value associated with the ID.

Parameters:

id - the id of the long literal to look up

Returns:

the value of the long literal, or null if it does not exist

getLongLiteralID

protected long getLongLiteralID(java.lang.String value,
                                boolean add)

Returns the ID of the given long literal. Optionally adds the long literal and returns the new ID if it does not already exist.

Parameters:

value - the long literal

add - whether or not to add the long literal if it does not already exist

Returns:

the ID of the long literal

getWhereClause

protected java.lang.String getWhereClause(java.lang.String graph,
                                          java.lang.String subject,
                                          java.lang.String predicate,
                                          java.lang.String object)

Returns a SQL WHERE clause that matches the given raw statement values (non-null parameters).

Parameters:

graph - the graph, or null for any graph

subject - the subject, or null for any subject

predicate - the predicate, or null for any predicate

object - the object, or null for any object

Returns:

the corresponding SQL WHERE clause

executeNoErrorHandling

protected void executeNoErrorHandling(java.lang.String sql)
                               throws java.sql.SQLException

Executes the given SQL statement.

Parameters:

sql - the SQL statement

Throws:

java.sql.SQLException

executeQuery

public java.sql.ResultSet executeQuery(java.lang.String sql)
                                throws java.sql.SQLException

Executes the given SQL query.

Parameters:

sql - the SQL query

Returns:

the results

Throws:

java.sql.SQLException

executeUpdate

public int executeUpdate(java.lang.String sql)
                  throws java.sql.SQLException

Executes the given SQL update statement.

Parameters:

sql - the SQL query

Returns:

the number of rows affected

Throws:

java.sql.SQLException

handleInsert

public static void handleInsert(java.lang.String graph,
                                java.lang.String subject,
                                java.lang.String predicate,
                                java.lang.String object)

Called by the statement table insertion trigger to notify listeners.

Parameters:

graph - the graph

subject - the subject

predicate - the predicate

object - the object

handleDelete

public static void handleDelete(java.lang.String graph,
                                java.lang.String subject,
                                java.lang.String predicate,
                                java.lang.String object)

Called by the statement table deletion trigger to notify listeners.

Parameters:

graph - the graph

subject - the subject

predicate - the predicate

object - the object

nodeToString

public java.lang.String nodeToString(INode node,
                                     boolean addIfLong)

Returns the raw database representation of the given node.

If the node is a long literal, this method can optionally add it to the long literals table of the current store. This is neccessary when the result of this method will be used to add the node to the current store.

Parameters:

node - the node

addIfLong - whether or not to add long literals to the current store

Returns:

the raw database representation of the node

stringToNode

public INode stringToNode(java.lang.String value,
                          DataView view)

Instantiates the node given by the raw database representation. If the node is a resource, this method uses the given view to return a cached copy when available.

Parameters:

value - the raw database representation

view - the view to use as a resource cache

Returns:

the node