org.apache.xalan.lib.sql

Class XConnection


public class XConnection
extends java.lang.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, NodeList list)
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, String driver, String dbURL, Element protocolElem)
XConnection(ExpressionContext exprContext, String driver, String dbURL, String user, String password)

Method Summary

void
addParameter(String value)
Add an untyped value to the parameter list.
void
addParameterFromElement(Element e)
Add a single parameter to the parameter list formatted as an Element
void
addParameterFromElement(NodeList nl)
Add a section of parameters to the Parameter List Do each element from the list
void
addParameterWithType(String value, String Type)
Add a typed parameter to the parameter list.
void
clearParameters()
void
close()
Close the connection to the data source.
void
close(ExpressionContext exprContext, Object doc)
Close the connection to the data source.
XBooleanStatic
connect(ExpressionContext exprContext, Element protocolElem)
XBooleanStatic
connect(ExpressionContext exprContext, NodeList list)
XBooleanStatic
connect(ExpressionContext exprContext, String name)
Returns an XConnection from either a user created org.apache.xalan.lib.sql.ConnectionPool or a JNDI datasource.
XBooleanStatic
connect(ExpressionContext exprContext, String driver, String dbURL)
Create an XConnection object with just a driver and database URL.
XBooleanStatic
connect(ExpressionContext exprContext, String driver, String dbURL, Element protocolElem)
Create an XConnection object with a connection protocol
XBooleanStatic
connect(ExpressionContext exprContext, String driver, String dbURL, String user, String password)
Create an XConnection object with user ID and password.
void
disableDefaultConnectionPool()
Deprecated. Use setFeature("default-pool-enabled", "false");
void
disableStreamingMode()
Deprecated. Use setFeature("streaming", "false");
void
enableDefaultConnectionPool()
Deprecated. Use setFeature("default-pool-enabled", "true");
void
enableStreamingMode()
Deprecated. Use setFeature("streaming", "true");
ConnectionPool
getConnectionPool()
Allow the SQL Document to retrive a connection to be used to build the SQL Statement.
DTM
getError()
Provide access to the last error that occued.
String
getFeature(String feature)
Get feature options for this XConnection.
DTM
pquery(ExpressionContext exprContext, String queryString)
Execute a parameterized query statement by instantiating an
DTM
pquery(ExpressionContext exprContext, String queryString, String typeInfo)
Execute a parameterized query statement by instantiating an
DTM
query(ExpressionContext exprContext, String queryString)
Execute a query statement by instantiating an
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.
void
setError(Exception excp, SQLDocument doc, SQLWarning warn)
Set an error and/or warning on this connection.
void
setFeature(String feature, String setting)
Set feature options for this XConnection.
void
skipRec(ExpressionContext exprContext, Object o, int value)
The purpose of this routine is to force the DB cursor to skip forward N records.

Constructor Details

XConnection

public XConnection()

XConnection

public XConnection(ExpressionContext exprContext,
                   NodeList list)
Parameters:
exprContext -
list -

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.

XConnection

public XConnection(ExpressionContext exprContext,
                   String driver,
                   String dbURL)
Parameters:
exprContext -
driver -
dbURL -

XConnection

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

XConnection

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

Method Details

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()
            throws SQLException
Close the connection to the data source.

close

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

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 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,
                              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".

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.

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 XStatement} object. The XStatement executes the query, and uses the result set to create aRowSet}, a row-set element.
Parameters:
exprContext -
queryString - the SQL query.
Returns:
XStatement implements NodeIterator.

pquery

public DTM pquery(ExpressionContext exprContext,
                  String queryString,
                  String typeInfo)
Execute a parameterized query statement by instantiating an XStatement} object. The XStatement executes the query, and uses the result set to create aRowSet}, 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.
Parameters:
exprContext -
queryString - the SQL query.
typeInfo -
Returns:
XStatement implements NodeIterator.

query

public DTM query(ExpressionContext exprContext,
                 String queryString)
Execute a query statement by instantiating an XStatement} object. The XStatement executes the query, and uses the result set to create aRowSet}, a row-set element.
Parameters:
exprContext -
queryString - the SQL query.
Returns:
XStatement implements NodeIterator.

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) 2005 Apache XML Project. All Rights Reserved.