org.apache.xalan.lib.sql

Class XConnection

public class XConnection extends Object

An XSLT extension that allows a stylesheet to access JDBC data. It is accessed by specifying a namespace URI as follows:
    xmlns:sql="http://xml.apache.org/xalan/sql"
 
From the stylesheet perspective, XConnection provides 3 extension functions: new(), query(), and close(). Use new() to call one of XConnection constructors, which establishes a JDBC driver connection to a data source and returns an XConnection object. Then use the XConnection object query() method to return a result set in the form of a row-set element. When you have finished working with the row-set, call the XConnection object close() method to terminate the connection.
Constructor Summary
XConnection()
XConnection(ExpressionContext exprContext, String connPoolName)
Constructs a new XConnection and attempts to connect to a datasource as defined in the connect(ExpressionContext exprContext, String connPoolName) method.
XConnection(ExpressionContext exprContext, String driver, String dbURL)
XConnection(ExpressionContext exprContext, NodeList list)
XConnection(ExpressionContext exprContext, String driver, String dbURL, String user, String password)
XConnection(ExpressionContext exprContext, String driver, String dbURL, Element protocolElem)
Method Summary
voidaddParameter(String value)
Add an untyped value to the parameter list.
voidaddParameterFromElement(Element e)
Add a single parameter to the parameter list formatted as an Element
voidaddParameterFromElement(NodeList nl)
Add a section of parameters to the Parameter List Do each element from the list
voidaddParameterWithType(String value, String Type)
Add a typed parameter to the parameter list.
voidclearParameters()
voidclose()
Close the connection to the data source.
voidclose(ExpressionContext exprContext, Object doc)
Close the connection to the data source.
XBooleanStaticconnect(ExpressionContext exprContext, String name)
Returns an XConnection from either a user created org.apache.xalan.lib.sql.ConnectionPool or a JNDI datasource.
XBooleanStaticconnect(ExpressionContext exprContext, String driver, String dbURL)
Create an XConnection object with just a driver and database URL.
XBooleanStaticconnect(ExpressionContext exprContext, Element protocolElem)
XBooleanStaticconnect(ExpressionContext exprContext, NodeList list)
XBooleanStaticconnect(ExpressionContext exprContext, String driver, String dbURL, String user, String password)
Create an XConnection object with user ID and password.
XBooleanStaticconnect(ExpressionContext exprContext, String driver, String dbURL, Element protocolElem)
Create an XConnection object with a connection protocol
voiddisableDefaultConnectionPool()
See enableDefaultConnectionPool
voiddisableStreamingMode()
Control how the SQL Document uses memory.
voidenableDefaultConnectionPool()
There is a problem with some JDBC drivers when a Connection is open and the JVM shutsdown.
voidenableStreamingMode()
Control how the SQL Document uses memory.
ConnectionPoolgetConnectionPool()
Allow the SQL Document to retrive a connection to be used to build the SQL Statement.
DTMgetError()
Provide access to the last error that occued.
StringgetFeature(String feature)
Get feature options for this XConnection.
DTMpquery(ExpressionContext exprContext, String queryString)
Execute a parameterized query statement by instantiating an
DTMpquery(ExpressionContext exprContext, String queryString, String typeInfo)
Execute a parameterized query statement by instantiating an
DTMquery(ExpressionContext exprContext, String queryString)
Execute a query statement by instantiating an
voidsetError(Exception excp, ExpressionContext expr)
This is an internal version of Set Error that is called withen XConnection where there is no SQLDocument created yet.
voidsetError(Exception excp, SQLDocument doc, SQLWarning warn)
Set an error and/or warning on this connection.
voidsetFeature(String feature, String setting)
Set feature options for this XConnection.
voidskipRec(ExpressionContext exprContext, Object o, int value)
The purpose of this routine is to force the DB cursor to skip forward N records.

Constructor Detail

XConnection

public XConnection()

XConnection

public XConnection(ExpressionContext exprContext, String connPoolName)
Constructs a new XConnection and attempts to connect to a datasource as defined in the connect(ExpressionContext exprContext, String connPoolName) method. org.apache.xalan.lib.sql.ConnectionPool or a JNDI datasource.

Parameters: exprContext Context automatically passed from the XSLT sheet. name The name of the ConnectionPool or the JNDI DataSource path.

XConnection

public XConnection(ExpressionContext exprContext, String driver, String dbURL)

Parameters: exprContext driver dbURL

XConnection

public XConnection(ExpressionContext exprContext, NodeList list)

Parameters: exprContext list

XConnection

public XConnection(ExpressionContext exprContext, String driver, String dbURL, String user, String password)

Parameters: exprContext driver dbURL user password

XConnection

public XConnection(ExpressionContext exprContext, String driver, String dbURL, Element protocolElem)

Parameters: exprContext driver dbURL protocolElem

Method Detail

addParameter

public void addParameter(String value)
Add an untyped value to the parameter list.

Parameters: value

addParameterFromElement

public void addParameterFromElement(Element e)
Add a single parameter to the parameter list formatted as an Element

Parameters: e

addParameterFromElement

public void addParameterFromElement(NodeList nl)
Add a section of parameters to the Parameter List Do each element from the list

Parameters: nl

addParameterWithType

public void addParameterWithType(String value, String Type)
Add a typed parameter to the parameter list.

Parameters: value Type

clearParameters

public void clearParameters()

close

public void close()
Close the connection to the data source.

Throws: SQLException

close

public void close(ExpressionContext exprContext, Object doc)
Close the connection to the data source. Only close the connections for a single document.

Throws: SQLException

connect

public XBooleanStatic connect(ExpressionContext exprContext, String name)
Returns an XConnection from either a user created org.apache.xalan.lib.sql.ConnectionPool or a JNDI datasource. This method first tries to resolve the passed name against ConnectionPools registered with ConnectionPoolManager. If that fails, it attempts to find the name as a JNDI DataSource path.

Parameters: exprContext Context automatically passed from the XSLT sheet. name The name of the ConnectionPool or the JNDI DataSource path.

connect

public XBooleanStatic connect(ExpressionContext exprContext, String driver, String dbURL)
Create an XConnection object with just a driver and database URL.

Parameters: exprContext driver JDBC driver of the form foo.bar.Driver. dbURL database URL of the form jdbc:subprotocol:subname.

connect

public XBooleanStatic connect(ExpressionContext exprContext, Element protocolElem)

Parameters: exprContext protocolElem

connect

public XBooleanStatic connect(ExpressionContext exprContext, NodeList list)

Parameters: exprContext list

connect

public XBooleanStatic connect(ExpressionContext exprContext, String driver, String dbURL, String user, String password)
Create an XConnection object with user ID and password.

Parameters: exprContext driver JDBC driver of the form foo.bar.Driver. dbURL database URL of the form jdbc:subprotocol:subname. user user ID. password connection password.

connect

public XBooleanStatic connect(ExpressionContext exprContext, String driver, String dbURL, Element protocolElem)
Create an XConnection object with a connection protocol

Parameters: exprContext driver JDBC driver of the form foo.bar.Driver. dbURL database URL of the form jdbc:subprotocol:subname. protocolElem list of string tag/value connection arguments, normally including at least "user" and "password".

disableDefaultConnectionPool

public void disableDefaultConnectionPool()

Deprecated: Use setFeature("default-pool-enabled", "false");

See enableDefaultConnectionPool

disableStreamingMode

public void disableStreamingMode()

Deprecated: Use setFeature("streaming", "false");

Control how the SQL Document uses memory. In Streaming Mode, memory consumption is greatly reduces so you can have queries of unlimited size but it will not let you traverse the data more than once.

enableDefaultConnectionPool

public void enableDefaultConnectionPool()

Deprecated: Use setFeature("default-pool-enabled", "true");

There is a problem with some JDBC drivers when a Connection is open and the JVM shutsdown. If there is a problem, there is no way to control the currently open connections in the pool. So for the default connection pool, the actuall pooling mechinsm is disabled by default. The Stylesheet designer can re-enabled pooling to take advantage of connection pools. The connection pool can even be disabled which will close all outstanding connections.

enableStreamingMode

public void enableStreamingMode()

Deprecated: Use setFeature("streaming", "true");

Control how the SQL Document uses memory. In Streaming Mode, memory consumption is greatly reduces so you can have queries of unlimited size but it will not let you traverse the data more than once.

getConnectionPool

public ConnectionPool getConnectionPool()
Allow the SQL Document to retrive a connection to be used to build the SQL Statement.

getError

public DTM getError()
Provide access to the last error that occued. This error may be over written when the next operation occurs.

getFeature

public String getFeature(String feature)
Get feature options for this XConnection.

Parameters: feature The name of the feature to get the setting for.

Returns: The setting of the specified feature. Will be "true" or "false" (null if the feature is not known)

pquery

public DTM pquery(ExpressionContext exprContext, String queryString)
Execute a parameterized query statement by instantiating an

Parameters: exprContext queryString the SQL query.

Returns: XStatement implements NodeIterator.

Throws: SQLException

UNKNOWN: org.apache.xalan.lib.sql.XStatement XStatement} object. The XStatement executes the query, and uses the result set to create a org.apache.xalan.lib.sql.RowSet RowSet}, a row-set element.

pquery

public DTM pquery(ExpressionContext exprContext, String queryString, String typeInfo)
Execute a parameterized query statement by instantiating an

Parameters: exprContext queryString the SQL query. typeInfo

Returns: XStatement implements NodeIterator.

Throws: SQLException

UNKNOWN: org.apache.xalan.lib.sql.XStatement XStatement} object. The XStatement executes the query, and uses the result set to create a org.apache.xalan.lib.sql.RowSet RowSet}, a row-set element. This method allows for the user to pass in a comma seperated String that represents a list of parameter types. If supplied the parameter types will be used to overload the current types in the current parameter list.

query

public DTM query(ExpressionContext exprContext, String queryString)
Execute a query statement by instantiating an

Parameters: exprContext queryString the SQL query.

Returns: XStatement implements NodeIterator.

Throws: SQLException

UNKNOWN: org.apache.xalan.lib.sql.XStatement XStatement} object. The XStatement executes the query, and uses the result set to create a org.apache.xalan.lib.sql.RowSet RowSet}, a row-set element.

setError

public void setError(Exception excp, ExpressionContext expr)
This is an internal version of Set Error that is called withen XConnection where there is no SQLDocument created yet. As in the Connect statement or creation of the ConnectionPool.

setError

public void setError(Exception excp, SQLDocument doc, SQLWarning warn)
Set an error and/or warning on this connection.

setFeature

public void setFeature(String feature, String setting)
Set feature options for this XConnection.

Parameters: feature The name of the feature being set, currently supports (streaming, inline-variables, multiple-results, cache-statements, default-pool-enabled). setting The new setting for the specified feature, currently "true" is true and anything else is false.

skipRec

public void skipRec(ExpressionContext exprContext, Object o, int value)
The purpose of this routine is to force the DB cursor to skip forward N records. You should call this function after [p]query to help with pagination. i.e. Perfrom your select, then skip forward past the records you read previously.

Parameters: exprContext o value

Copyright B) 2006 Apache XML Project. All Rights Reserved.