com.ddtek.xquery3
Interface XQDataSource

All Known Implementing Classes:

DDXQDataSource

public interface XQDataSource

An XQDataSource is a factory for XQConnection objects. The datasource may be obtained from a JNDI source or through other means.
The XQuery connection (XQConnection) objects may be created using an existing JDBC connection. This is an optional feature that may not be supported by all implementations. If the implementation supports this mechanism, then the XQuery connection may inherit some of the JDBC connection's properties, such as login timeout, log writer etc.

Method Summary

XQConnection	getConnection() Attempts to create a connection to an XML datasource.
XQConnection	getConnection(Connection con) Attempts to create a connection to an XML datasource using an existing JDBC connection.
XQConnection	getConnection(String username, String passwd) Attempts to establish a connection to an XML datasource using the supplied username and password.
int	getLoginTimeout() Gets the maximum time in seconds that this datasource can wait while attempting to connect to a database.
PrintWriter	getLogWriter() Retrieves the log writer for this XQDataSource object.
String	getProperty(String name) Returns the current value of the named property if set, else null.
String[]	getSupportedPropertyNames() Returns an array containing the property names supported by this XQDataSource.
void	setCommonHandler(XQCommonHandler hdlr) Sets the default common handler to be used for converting items to and from Java objects in the getObject methods on an item.
void	setLoginTimeout(int seconds) Sets the maximum time in seconds that this datasource will wait while attempting to connect to a database.
void	setLogWriter(PrintWriter out) Sets the log writer for this XQDataSource object to the given java.io.PrintWriter object.
void	setProperties(Properties props) Sets the data source properties from the specified Properties instance.
void	setProperty(String name, String value) Sets the named property to the specified value.

Method Detail

getConnection

public XQConnection getConnection()
                           throws XQException

Attempts to create a connection to an XML datasource.

Returns:

a connection to the XML datasource

Throws:

XQException - if a datasource access error occurs

getConnection

public XQConnection getConnection(Connection con)
                           throws XQException

Attempts to create a connection to an XML datasource using an existing JDBC connection. An XQJ implementation is not required to support this method. If it is not supported, then an exception (XQException) is thrown. The XQJ and JDBC connections will operate under the same transaction context.

Parameters:

con - an existing JDBC connection

Returns:

a connection to the XML datasource

Throws:

XQException - if (1) a datasource access error occurs, or (2) the implementation does not support this method of getting an XQConnection

getConnection

public XQConnection getConnection(String username,
                                  String passwd)
                           throws XQException

Attempts to establish a connection to an XML datasource using the supplied username and password.

Parameters:

username - the user on whose behalf the connection is being made

passwd - the user's password

Returns:

a connection to the XML datasource

Throws:

XQException - if a datasource access error occurs

getLoginTimeout

public int getLoginTimeout()
                    throws XQException

Gets the maximum time in seconds that this datasource can wait while attempting to connect to a database. A value of zero means that the timeout is the default system timeout if there is one; otherwise, it means that there is no timeout. When a XQDataSource object is created, the login timeout is initially zero. It is implementation-defined whether the returned login timeout is actually used by the data source implementation.

Returns:

the datasource login time limit

Throws:

XQException - if a datasource access error occurs

getLogWriter

public PrintWriter getLogWriter()
                         throws XQException

Retrieves the log writer for this XQDataSource object. The log writer is a character output stream to which all logging and tracing messages for this datasource will be printed. This includes messages printed by the methods of this object, messages printed by methods of other objects manufactured by this object, and so on. When a XQDataSource object is created, the log writer is initially null; in other words, the default is for logging to be disabled.

Returns:

the log writer for this datasource or null if logging is disabled

Throws:

XQException - if a datasource access error occurs

getSupportedPropertyNames

public String[] getSupportedPropertyNames()

Returns an array containing the property names supported by this XQDataSource. Implementations that support user name and password must recognize the user name and password properties listed below.

user	the user name to use for creating a connection
password	the password to use for creating a connection

Any additional properties are implementation-defined.

Returns:

String[] an array of property names supported by this implementation

setProperty

public void setProperty(String name,
                        String value)
                 throws XQException

Sets the named property to the specified value. If a property with the same name was already set, then this method will override the old value for that property with the new value.

If the implementation does not support the given property or if it can determine that the value given for this property is invalid, then an exception is thrown. If an exception is thrown, then no previous value is overwritten.

Parameters:

name - the name of the property to set

value - the value of the named property

Throws:

XQException - if (1) the given property is not recognized, or (2) the value for the given property is determined to be invalid

getProperty

public String getProperty(String name)
                   throws XQException

Returns the current value of the named property if set, else null. If the implementation does not support the given property then an exception is raised.

Parameters:

name - the name of the property whose value is needed

Returns:

String representing the value of the required property if set, else null

Throws:

XQException - if a given property is not supported

setProperties

public void setProperties(Properties props)
                   throws XQException

Sets the data source properties from the specified Properties instance. Properties set before this call will still apply but those with the same name as any of these properties will be replaced. Properties set after this call also apply and may replace properties set during this call.

If the implementation does not support one or more of the given property names, or if it can determine that the value given for a specific property is invalid, then an exception is thrown. If an exception is thrown, then no previous value is overwritten. is invalid, then an exception is raised.

Parameters:

props - the list of properties to set

Throws:

XQException - if (1) a given property is not recognized, or (2) the value for a given property is determined to be invalid

setCommonHandler

public void setCommonHandler(XQCommonHandler hdlr)
                      throws XQException

Sets the default common handler to be used for converting items to and from Java objects in the getObject methods on an item. An XQJ implementation is not required to support this method. If it is not supported, then an exception (XQException) is thrown.

Parameters:

hdlr - the XQCommonHandler to use

Throws:

XQException - if this method is not supported by the implementation

See Also:

XQItemAccessor.getObject

setLoginTimeout

public void setLoginTimeout(int seconds)
                     throws XQException

Sets the maximum time in seconds that this datasource will wait while attempting to connect to a database. A value of zero specifies that the timeout is the default system timeout if there is one; otherwise, it specifies that there is no timeout. When a XQDataSource object is created, the login timeout is initially zero. It is implementation-defined whether the specified login timeout is actually used by the data source implementation. If the connection is created over an existing JDBC connection, then the login timeout value from the underlying JDBC connection may be used.

Parameters:

seconds - the datasource login time limit

Throws:

XQException - if a datasource access error occurs

setLogWriter

public void setLogWriter(PrintWriter out)
                  throws XQException

Sets the log writer for this XQDataSource object to the given java.io.PrintWriter object. The log writer is a character output stream to which all logging and tracing messages for this datasource will be printed. This includes messages printed by the methods of this object, messages printed by methods of other objects manufactured by this object, and so on. When a XQDataSource object is created the log writer is initially null; in other words, the default is for logging to be disabled.

Parameters:

out - the new log writer; to disable logging, set to null

Throws:

XQException - if a datasource access error occurs