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Programming WebLogic JDBC

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Using Third-Party Drivers with WebLogic Server

The following sections describe how to set up and use third-party JDBC drivers:

 


Overview of Third-Party JDBC Drivers

WebLogic Server works with third-party JDBC drivers that offer the following functionality:

For more information, see "Supported Database Configurations" in Supported Configurations for WebLogic Platform 8.1.

The following sections describe how to set up and use third-party JDBC drivers with WebLogic Server:

Using Third-Party JDBC Drivers Installed with WebLogic Server

The following third-party drivers are installed with WebLogic Server:

Note: JDBC Driver support changed in the following releases:

Drivers installed with Weblogic server are located in the WL_HOME\server\lib folder (where WL_HOME is the folder where WebLogic Platform is installed) with weblogic.jar. The manifest in weblogic.jar lists these files so that they are loaded when weblogic.jar is loaded (when the server starts). Therefore, you do not need to add these JDBC drivers to your CLASSPATH.

Using Third-Party JDBC Drivers not Installed with WebLogic Server

If you plan to use a third-party JDBC driver that is not installed with WebLogic Server, you need to update the WebLogic Server's classpath to include the location of the JDBC driver classes. Edit the commEnv.cmd/sh script in WL_HOME/common/bin and prepend your classes as described in "Modifying the Classpath" in WebLogic Server Command Reference.

 


Using the Oracle Thin Driver

The following secions provide information on using the Oracle Thin Driver:

Updating the Oracle 10g Driver

If you plan to use a different version of the driver, you must replace the ojdbc14.jar file in WL_HOME\server\lib with an updated version of the file from Oracle or add the new file to the front of your CLASSPATH. You can download driver updates from the Oracle Web site at http://otn.oracle.com/software/content.html.

Note: The ojdbc14.jar file replaces classes12.zip as the source for Oracle Thin driver classes. This version of the driver is for use with a Java 2 SDK version 1.4.

Using the Oracle 9.2 Driver

The WL_HOME\server\ext\jdbc\oracle folder (where WL_HOME is the folder where WebLogic Platform is installed) of your WebLogic Server installation includes subfolders for the 9.2.0 and 10g versions of the Oracle Thin driver.

To use the 9.2.0 version of the driver:

  1. In Windows Explorer or a command shell, navigate to the WL_HOME\server\ext\jdbc\oracle\920 folder.
  2. Copy ojdbc14.jar.
  3. In Windows Explorer or a command shell, navigate to WL_HOME\server\lib and replace the existing version of ojdbc14.jar with the version you copied.

To revert to version 10g (the default), follow the instructions above, but copy from the following folder: WL_HOME\server\ext\jdbc\oracle\10g.

Package Change for Oracle Thin Driver 9.x and 10g

For Oracle 8.x and previous releases, the package that contained the Oracle Thin driver was oracle.jdbc.driver. When configuring a JDBC connection pool that uses the Oracle 8.1.7 Thin driver, you specify the DriverName (Driver Classname) as oracle.jdbc.driver.OracleDriver. For Oracle 9.x and 10g, the package that contains the Oracle Thin driver is oracle.jdbc. When configuring a JDBC connection pool that uses the Oracle 9.x or 10g Thin driver, you specify the DriverName (Driver Classname) as oracle.jdbc.OracleDriver. You can use the oracle.jdbc.driver.OracleDriver class with the 9.x and 10g drivers, but Oracle may not make future feature enhancements to that class.

See the Oracle documentation for more details about the Oracle Thin driver.

Note: The package change does not apply to the XA version of the driver. For the XA version of the Oracle Thin driver, use oracle.jdbc.xa.client.OracleXADataSource as the DriverName (Driver Classname) in a JDBC connection pool.

Character Set Support with nls_charset12.zip

The Oracle Thin driver includes Globalization Support for all Oracle character sets for CHAR and NCHAR datatypes not retrieved or inserted as part of an Oracle object or collection type.

However, in the case of the CHAR and VARCHAR data portion of Oracle objects and collections, the Oracle Thin driver includes Globalization Support support for only the following character sets:

If you use other character sets with CHAR and NCHAR data in Oracle object types and collections, you must include nls_charset.zip in your CLASSPATH. If this file is not in your CLASSPATH, you will see the following exception:

java.sql.SQLException: Non supported character set: oracle-character-set-178

The nls_charset12.zip file is installed with WebLogic Server in the WL_HOME\server\ext\jdbc\oracle\920 and WL_HOME\server\ext\jdbc\oracle\10g folders (where WL_HOME is the folder where WebLogic Server is installed). See Using Third-Party JDBC Drivers not Installed with WebLogic Server for instructions to set your CLASSPATH.

Note: For Globalization Support with the 10g version of the driver, Oracle supplies the orai18n.jar file, which replaces nls_charset.zip. If you use character sets other than US7ASCII, WE8DEC, WE8ISO8859P1 and UTF8 with CHAR and NCHAR data in Oracle object types and collections, you must include orai18n.jar in your CLASSPATH. orai18n.jar is not installed with WebLogic Server. You can download it from the Oracle Web site.

Using the Oracle Thin Driver in Debug Mode

The WL_HOME\server\ext\jdbc\oracle\ (where WL_HOME is the folder where WebLogic Server is installed) includes subfolders for the 9.2.0 and 10g versions of the Oracle Thin driver. Each subfolder contains a ojdbc14_g.jar file, which contains the necessary classes to support debug and trace.

To use the Oracle Thin driver in debug mode:

  1. Prepend the path of the ojdbc14_g.jar file to the WebLogic Server classpath as described in "Modifying the Classpath" in WebLogic Server Command Reference.
  2. Turn on JDBC logging (see "Enabling JDBC Logging" in the WebLogic Server Administration Console Online Help).

 


Updating the Sybase jConnect Driver

WebLogic Server ships with Sybase jConnect 4.5 (jConnect.jar), 5.5 (jconn2.jar), and 6.0 (jconn3.jar) preconfigured and ready to use. To use a different version, replace the Sybase.jar file located at WL_HOME\server\lib with the updated version of the file from the DBMS vendor.

To revert to versions installed with WebLogic Server, copy the following files and place them in the WL_HOME\server\lib folder:

 


Installing and Using the IBM DB2 Type 2 JDBC Driver

The IBM DB2 client installation includes a type 2 JDBC driver that you can use to create connections to a DB2 database in a connection pool. By default, the DB2 client uses a JDBC 1.x version of the driver. To use the JDBC 2.0-compliant version of the driver, follow the steps below.

Note: You must install the DB2 client on each machine that you want to use the DB2 type 2 JDBC driver to connect to the database. As with all type 2 drivers, the DB2 driver relies on libraries in the database client to access the database.

  1. Stop the DB2 JDBC Applet Server Windows Service.
  2. In the db2_install_path\java12 directory, where db2_install_path is the directory in which you installed the DB2 client, run the usejdbc2.bat batch file.
  3. This batch file creates a folder for the JDBC 1.2 version of JDBC driver and then replaces files in the db2_install_path\java folder with the JDBC 2.0 version of the driver.

  4. Start the DB2 JDBC Applet Server Windows service.
  5. Check the contents of the db2_install_path\java12\inuse file. If JDBC 2.0 is being used, the file will contain JDBC 2.0.

Before you can use the DB2 type 2 JDBC driver in a connection pool, you must add the driver classes to your CLASSPATH and the DB2 client libraries to your PATH. You may want to do this in the start scripts for your domain. For example:

set CLASSPATH=db2_install_path\java\db2java.zip;%CLASSPATH%
set PATH=db2_install_path\bin;%PATH%

Where db2_install_path is the directory in which you installed the DB2 client.

If you plan to use the XA version of the IBM DB2 driver, see "Using the IBM DB2 Type 2 JDBC Driver" in Programming WebLogic JTA for configuration instructions.

To create a connection pool with connections that use the DB2 type 2 driver, you can use the JDBC Connection Pool Assistant in the Administration Console (see "JDBC Connection Pools" in the Administration Console Online Help) or the JMX API (see Creating a Connection Pool Dynamically).

Connection Pool Attributes when using the IBM DB2 Type 2 JDBC Driver

Use the attributes as described in Table 5-1 and Table 5-2 when creating a connection pool that uses the IBM DB2 Type 2 JDBC Driver.

Table 5-1 Non-XA Connection Pool Attributes Using the DB2 Type 2 JDBC Driver

Attribute

Value

URL

jdbc:db2:dbname

Driver Class Name

COM.ibm.db2.jdbc.app.DB2Driver

Properties

user=username
DatabaseName=dbname

Password

password

TestConnectionsOnCreate

true

TestConnectionsOnReserve

true

TestTableName

SYSIBM.SYSTABLES

Target

serverName


 

The database name in the URL and in the Properties string must be a database configured for use in the DB2 client, such as a database listed in the Client Configuration Assistant. Also, the database user must be able to select from the table specified in TestTableName.

An entry in the config.xml file may look like the following:

    <JDBCConnectionPool DriverName="COM.ibm.db2.jdbc.app.DB2Driver"
Name="MyJDBC Connection Pool"
Password="{3DES}Pd8QwSJ5FtLEfuiA/vcy3g=="
Properties="user=dbuser;DatabaseName=db1"
Targets="myserver"
TestConnectionsOnCreate="true"
TestConnectionsOnReserve="true"
TestTableName="SYSIBM.SYSTABLES"
URL="jdbc:db2:db1"/>

Table 5-2 XA Connection Pool Attributes Using the DB2 Type 2 JDBC Driver

Attribute

Value

URL

jdbc:db2:dbname

Driver Class Name

COM.ibm.db2.jdbc.DB2XADataSource

Properties

user=username
DatabaseName=dbname

Password

password

TestConnectionsOnCreate

true

TestConnectionsOnReserve

true

TestTableName

SYSIBM.SYSTABLES

KeepXAConnTillTxComplete

true

Target

serverName


 

The database name in the URL and in the Properties string must be a database configured for use in the DB2 client, such as a database listed in the Client Configuration Assistant.

DB2 requires that all processing for a global transaction occurs on a single database connection, so you must set KeepXAConnTillTxComplete to true.

An entry in the config.xml file may look like the following:

    <JDBCConnectionPool DriverName="COM.ibm.db2.jdbc.DB2XADataSource"
KeepXAConnTillTxComplete="true"
Name="My XA JDBC Connection Pool"
Password="{3DES}Pd8QwSJ5FtLEfuiA/vcy3g=="
Properties="user=dbuser;DatabaseName=db1"
Targets="myserver"
TestConnectionsOnCreate="true"
TestConnectionsOnReserve="true"
TestTableName="SYSIBM.SYSTABLES"
URL="jdbc:db2:db1"/>

 


Installing and Using the SQL Server 2000 Driver for JDBC from Microsoft

The Microsoft SQL Server 2000 Driver for JDBC is available for download to all licensed SQL Server 2000 customers at no charge. The driver is a Type 4 JDBC driver that supports a subset of the JDBC 2.0 Optional Package. When you install the Microsoft SQL Server 2000 Driver for JDBC, the supporting documentation is optionally installed with it. You should refer to that documentation for the most comprehensive information about the driver. Also, see the release manifest for known issues.

The following sections describe how to install and configure the Microsoft SQL Server 2000 Driver for JDBC.

Installing the MS SQL Server JDBC Driver on a Windows System

Follow these instructions to install the SQL Server 2000 Driver for JDBC on a Windows server:

  1. Download the Microsoft SQL Server 2000 Driver for JDBC (setup.exe file) from the Microsoft MSDN Web site. Save the file in a temporary directory on your local computer.
  2. Run setup.exe from the temporary directory and follow the instructions on the screen.
  3. Add the path to the following files to your CLASSPATH:
  4. Where install_dir is the folder in which you installed the driver. For example:

    set CLASSPATH=install_dir\lib\msbase.jar;
    install_dir\lib\msutil.jar;install_dir\lib\mssqlserver.jar;
    %CLASSPATH%

Installing the MS SQL Server JDBC Driver on a Unix System

Follow these instructions to install the SQL Server 2000 Driver for JDBC on a UNIX server:

  1. Download the Microsoft SQL Server 2000 Driver for JDBC (mssqlserver.tar file) from the Microsoft MSDN Web site. Save the file in a temporary directory on your local computer.
  2. Change to the temporary directory and untar the contents of the file using the following command:
  3. tar -xvf mssqlserver.tar
  4. Execute the following command to run the installation script:
  5. install.ksh
  6. Follow the instructions on the screen. When prompted to enter an installation directory, make sure you enter the full path to the directory.
  7. Add the path to the following files to your CLASSPATH:
  8. Where install_dir is the folder in which you installed the driver. For example:

    export CLASSPATH=install_dir/lib/msbase.jar:
    install_dir/lib/msutil.jar:install_dir/lib/mssqlserver.jar:
    $CLASSPATH

Connection Pool Attributes when using the Microsoft SQL Server Driver for JDBC

Use the attributes in Table 5-3 when creating a connection pool that uses the Microsoft SQL Server Driver for JDBC.

Table 5-3 Connection Pool Attributes Using the Microsoft SQL Server Driver for JDBC

Attribute

Value

URL

jdbc:microsoft:sqlserver://server_name:port

Driver Class Name

com.microsoft.jdbc.sqlserver.SQLServerDriver

Properties

user=username
DatabaseName=dbname
selectMethod=cursor

Password

password

Target

serverName


 

An entry in the config.xml file may look like the following:

    <JDBCConnectionPool 
Name="mssqlPool"
DriverName="com.microsoft.jdbc.sqlserver.SQLServerDriver"
URL="jdbc:microsoft:sqlserver://db4:1433"
Properties="databasename=db4;user=sa;
selectMethod=cursor"
Password="{3DES}vlsUYhxlJ/I="
InitialCapacity="4"
CapacityIncrement="2"
MaxCapacity="10"
Targets="examplesServer"
/>

Note: You must add selectMethod=cursor to the list of connection properties in order to use connections in a transactional mode. This enables your applications to have multiple concurrent statements open from a given connection, which is required for pooled connections.

Without setting selectMethod=cursor, this JDBC driver creates an internal cloned connection for each concurrent statement, each as a different DBMS user. This makes it impossible to concurrently commit transactions and may cause deadlocks.

 


Installing and Using the IBM Informix JDBC Driver

If you want to use WebLogic Server with an Informix database, BEA recommends that you use the IBM Informix JDBC driver, available from the IBM Web site at http://www-3.ibm.com/software/data/informix/tools/jdbc/. The IBM Informix JDBC driver is available to use for free without support. You may have to register with IBM to download the product. Download the driver from the JDBC/EMBEDDED SQLJ section, and follow the instructions in the install.txt file included in the downloaded zip file to install the driver.

After you download and install the driver, follow these steps to prepare to use the driver with WebLogic Server:

  1. Copy ifxjdbc.jar and ifxjdbcx.jar files from INFORMIX_INSTALL\lib and paste it in WL_HOME\server\lib folder, where:
  2. INFORMIX_INSTALL is the root directory where you installed the Informix JDBC driver, and

    WL_HOME is the folder where you installed WebLogic Platform, typically c:\bea\weblogic81.

  3. Add the path to ifxjdbc.jar and ifxjdbcx.jar to your CLASSPATH. For example:
  4. set CLASSPATH=%WL_HOME%\server\lib\ifxjdbc.jar;%WL_HOME%\server\lib\ifxjdbcx.jar;%CLASSPATH%

    You can also add the path for the driver files to the set CLASSPATH statement in your start script for WebLogic Server.

Connection Pool Attributes when using the IBM Informix JDBC Driver

Use the attributes as described in Table 5-4 and Table 5-5 when creating a connection pool that uses the IBM Informix JDBC driver.

Table 5-4 Non-XA Connection Pool Attributes Using the Informix JDBC Driver

Attribute

Value

URL

jdbc:informix-sqli:dbserver_name_or_ip:port/dbname:informixserver=ifx_server_name

Driver Class Name

com.informix.jdbc.IfxDriver

Properties

user=username
url=jdbc:informix-sqli:dbserver_name_or_ip:port/dbname:informixserver=ifx_server_name
portNumber=1543
databaseName=dbname
ifxIFXHOST=ifx_server_name
serverName=dbserver_name_or_ip

Password

password

Login Delay Seconds

1

Target

serverName

An entry in the config.xml file may look like the following:

    <JDBCConnectionPool 
DriverName="com.informix.jdbc.IfxDriver"
InitialCapacity="3"
LoginDelaySeconds="1"
MaxCapacity="10"
Name="ifxPool"
Password="xxxxxxx"
Properties="informixserver=ifxserver;user=informix"
Targets="examplesServer"
URL="jdbc:informix-sqli:ifxserver:1543"
/>

Table 5-5 XA Connection Pool Attributes Using the Informix JDBC Driver

Attribute

Value

URL

leave blank

Driver Class Name

com.informix.jdbcx.IfxXADataSource

Properties

user=username
url=jdbc:informix-sqli://dbserver_name_or_ip:port_num/dbname:informixserver=dbserver_name_or_ip
password=password
portNumber =port_num;
databaseName=dbname
serverName=dbserver_name
ifxIFXHOST=dbserver_name_or_ip

Password

leave blank

Supports Local Transaction

true

Target

serverName

Note: In the Properties string, there is a space between portNumber and =.

An entry in the config.xml file may look like the following:

    <JDBCConnectionPool CapacityIncrement="2"
DriverName="com.informix.jdbcx.IfxXADataSource"
InitialCapacity="2" MaxCapacity="10"
Name="informixXAPool"
Properties="user=informix;url=jdbc:informix-sqli:
//111.11.11.11:1543/db1:informixserver=lcsol15;
password=informix;portNumber =1543;databaseName=db1;
serverName=dbserver1;ifxIFXHOST=111.11.11.11"
SupportsLocalTransaction="true" Targets="examplesServer"
TestConnectionsOnReserve="true" TestTableName="emp"/>

Note: If you create the connection pool using the Administration Console, you may need to stop and restart the server before the connection pool will deploy properly on the target server. This is a known issue.

Programming Notes for the IBM Informix JDBC Driver

Consider the following limitations when using the IBM Informix JDBC driver:

 


Getting a Connection with Your Third-Party Driver

The following sections describe how to get a database connection using a third-party, Type 4 driver, such as the Oracle Thin Driver. BEA recommends you use connection pools, data sources, and a JNDI lookup to establish your connection.

Using Connection Pools with a Third-Party Driver

First, you create the connection pool and data source using the Administration Console, then establish a connection using a JNDI Lookup.

Creating the Connection Pool and DataSource

See Configuring and Using Connection Pools and Configuring and Using DataSources for instructions to create a JDBC connection pool and a JDBC DataSource.

Using a JNDI Lookup to Obtain the Connection

To access the driver using JNDI, obtain a Context from the JNDI tree by providing the URL of your server, and then use that context object to perform a lookup using the DataSource Name.

For example, to access a DataSource called "myDataSource" that is defined in the Administration Console:

Context ctx = null;
Hashtable ht = new Hashtable();
ht.put(Context.INITIAL_CONTEXT_FACTORY,
"weblogic.jndi.WLInitialContextFactory");
ht.put(Context.PROVIDER_URL,
"t3://hostname:port");
  Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
  try {
ctx = new InitialContext(ht);
javax.sql.DataSource ds
= (javax.sql.DataSource) ctx.lookup ("myDataSource");
conn = ds.getConnection();
   // You can now use the conn object to create 
// Statements and retrieve result sets:
    stmt = conn.createStatement();
stmt.execute("select * from someTable");
rs = stmt.getResultSet();
...
//Close JDBC objects as soon as possible
stmt.close();
stmt=null;
    conn.close();
conn=null;
 }
catch (Exception e) {
// a failure occurred
log message;
}
finally {
try {
ctx.close();
} catch (Exception e) {
log message; }
try {
if (rs != null) rs.close();
} catch (Exception e) {
log message; }
try {
if (stmt != null) stmt.close();
} catch (Exception e) {
log message; }
try {
if (conn != null) conn.close();
} catch (Exception e) {
log message; }
}

(Where hostname is the name of the machine running your WebLogic Server and port is the port number where that machine is listening for connection requests.)

In this example a Hashtable object is used to pass the parameters required for the JNDI lookup. There are other ways to perform a JNDI lookup. For more information, see Programming WebLogic JNDI.

Notice that the JNDI lookup is wrapped in a try/catch block in order to catch a failed look up and also that the context is closed in a finally block.

Getting a Physical Connection from a Connection Pool

Note: BEA strongly discourages directly accessing a physical JDBC connection except for when it is absolutely required. See Limitations for Using a Physical Connection.

Standard practice is to cast a connection to the generic JDBC connection (a wrapped physical connection) provided by WebLogic Server. This allows the server instance to manage the connection for the connection pool, enable connection pool features, and maintain the quality of connections provided to applications. Occasionally, a DBMS vendor may provide extra non-standard JDBC-related classes that require direct access of the physical connection (the actual vendor JDBC connection). To directly access a physical connection in a connection pool, you must cast the connection using getVendorConnection .

The following sections provide information on getting a physical connection:

Opening a Connection

To get a physical database connection, you first get a connection from a connection pool as described in Using a JNDI Lookup to Obtain the Connection, then do one of the following:

Always limit direct access of physical database connections to vendor-specific calls. For all other situations, use the generic JDBC connection provided by WebLogic Server. Sample code to open a connection for vendor-specific calls is provided in Listing 5-1.

Listing 5-1 Code Sample to Open a Connection for Vendor-specific Calls

//Import this additional class and any vendor packages
//you may need.
import weblogic.jdbc.extensions.WLConnection
.
.
.
myJdbcMethod()
{
  // Connections from a connection pool should always be
// method-level variables, never class or instance methods.
Connection conn = null;
   try { 
ctx = new InitialContext(ht);
// Look up the data source on the JNDI tree and request
// a connection.
javax.sql.DataSource ds
= (javax.sql.DataSource) ctx.lookup ("myDataSource");
     // Always get a pooled connection in a try block where it is
// used completely and is closed if necessary in the finally
// block.
conn = ds.getConnection();
     // You can now cast the conn object to a WLConnection 
// interface and then get the underlying physical connection.
     java.sql.Connection vendorConn = 
((WLConnection)conn).getVendorConnection();

// do not close vendorConn
     // You could also cast the vendorConn object to a vendor 
// interface, such as:
// oracle.jdbc.OracleConnection vendorConn = (OracleConnection)
// ((WLConnection)conn).getVendorConnection()
     // If you have a vendor-specific method that requires the 
// physical connection, it is best not to obtain or retain
// the physical connection, but simply pass it implicitly
// where needed, eg: //vendor.special.methodNeedingConnection(((WLConnection)conn)).getVendorConnection());

Closing a Connection

When you are finished with your JDBC work, you should close the logical connection to get it back into the pool. When you are done with the physical connection:

You determine how a connection closes by setting the value of the Remove Infected Connections Enabled property in the administration console. See JDBC Connection Pool --> Configuration --> Connections in the Administration Console Help. Sample code to close a vendor-specific connection is shown in Listing 5-2.

Note: The Remove Infected Connections Enabled property applies only to applications that explicitly call getVendorConnection.

Listing 5-2 Sample Code to Close a Connection for Vendor-specific Calls

 // As soon as you are finished with vendor-specific calls,  
// nullify the reference to the connection.
// Do not keep it or close it.
// Never use the vendor connection for generic JDBC.
// Use the logical (pooled) connection for standard JDBC.
vendorConn = null;
     ... do all the JDBC needed for the whole method... 
     // close the logical (pooled) connection to return it to 
// the connection pool, and nullify the reference.
conn.close();
conn = null;
}
  catch (Exception e) 
{
// Handle the exception.
}
finally
{
// For safety, check whether the logical (pooled) connection
// was closed.
// Always close the logical (pooled) connection as the
// first step in the finally block.

Remove Infected Connections Enabled is True

When Remove infected Connections Enabled=false (default value) and you close the logical connection, the server instance discards the underlying physical connection and creates a new connection to replace it. This action ensures that the pool can guarantee to the next user that they are the sole user of the pool connection. This configuration provides a simple and safe way to close a connection. However, there is a performance loss because:

Remove Infected Connections Enabled is False

Note: Use Remove infected Connections Enabled=false only if you are sure that the exposed physical connection will never be retained or reused after the logical connection is closed.

When Remove infected Connections Enabled=false and you close the logical connection, the server instance simply returns the physical connection to the connection pool for reuse. Although this configuration minimizes performance losses, the server instance does not guarantee the quality of the connection or to effectively manage the connection after the logical connection is closed. You must make sure that the connection is suitable for reuse by other applications before it is returned to the connection pool.

Limitations for Using a Physical Connection

BEA strongly discourages using a physical connection instead of a logical connection from a connection pool. However, if you must use a physical connection, for example, to create a STRUCT, consider the following costs and limitations:

 


Using Vendor Extensions to JDBC Interfaces

Some database vendors provide additional proprietary methods for working with data from a database that uses their DBMS. These methods extend the standard JDBC interfaces. In previous releases of WebLogic Server, only specific JDBC extensions for a few vendors were supported. The current release of WebLogic Server supports all extension methods exposed as a public interface in the vendor's JDBC driver.

If the driver vendor does not expose the methods you need in a public interface, you should submit a request to the vendor to expose the methods in a public interface. WebLogic Server does provide support for extension methods in the Oracle Thin Driver for ARRAYs, STRUCTs, and REFs, even though the extension methods are not exposed in a public interface. See Using Oracle Extensions with the Oracle Thin Driver.

In general, WebLogic Server supports using vendor extensions in server-side code. To use vendor extensions in client-side code, the object type or data type must be serializable. Exceptions to this are the following object types:

WebLogic Server handles de-serialization for these object types so they can be used in client-side code.

Note: There are interoperability limitations when using different versions of WebLogic Server clients and servers. See Support for Vendor Extensions Between Versions of WebLogic Server Clients and Servers.

To use the extension methods exposed in the JDBC driver, you must include these steps in your application code:

The following sections provide details in code examples. For information about specific extension methods for a particular JDBC driver, refer to the documentation from the JDBC driver vendor.

Sample Code for Accessing Vendor Extensions to JDBC Interfaces

The following code examples use extension methods available in the Oracle Thin driver to illustrate how to use vendor extensions to JDBC. You can adapt these examples to fit methods exposed in your JDBC driver.

Import Packages to Access Vendor Extensions

Import the interfaces from the JDBC driver used to create the connection in the connection pool. This example uses interfaces from the Oracle Thin Driver.

import java.sql.*;
import java.util.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
import oracle.jdbc.*;
// Import driver interfaces. The driver must be the same driver
// used to create the database connection in the connection pool.

Get a Connection

Establish the database connection using JNDI, DataSource and connection pool objects. For information, see Using a JNDI Lookup to Obtain the Connection.

// Get a valid DataSource object for a connection pool.
// Here we assume that getDataSource() takes
// care of those details.
javax.sql.DataSource ds = getDataSource(args);
// get a java.sql.Connection object from the DataSource
java.sql.Connection conn = ds.getConnection();

Cast the Connection as a Vendor Connection

Now that you have the connection, you can cast it as a vendor connection. This example uses the OracleConnection interface from the Oracle Thin Driver.

orConn = (oracle.jdbc.OracleConnection)conn;
// This replaces the deprecated process of casting the connection
// to a weblogic.jdbc.vendor.oracle.OracleConnection. For example:
// orConn = (weblogic.jdbc.vendor.oracle.OracleConnection)conn;

Use Vendor Extensions

The following code fragment shows how to use the Oracle Row Prefetch method available from the Oracle Thin driver.

// Cast to OracleConnection and retrieve the 
// default row prefetch value for this connection.
int default_prefetch = 
((oracle.jdbc.OracleConnection)conn).getDefaultRowPrefetch();
// This replaces the deprecated process of casting the connection
// to a weblogic.jdbc.vendor.oracle.OracleConnection. For example:
// ((weblogic.jdbc.vendor.oracle.OracleConnection)conn).
// getDefaultRowPrefetch();
System.out.println("Default row prefetch 
is " + default_prefetch);
java.sql.Statement stmt = conn.createStatement();
// Cast to OracleStatement and set the row prefetch
// value for this statement. Note that this
// prefetch value applies to the connection between
// WebLogic Server and the database.
      ((oracle.jdbc.OracleStatement)stmt).setRowPrefetch(20);
   // This replaces the deprecated process of casting the
// statement to a weblogic.jdbc.vendor.oracle.OracleStatement.
// For example:
// ((weblogic.jdbc.vendor.oracle.OracleStatement)stmt).
// setRowPrefetch(20);
      // Perform a normal sql query and process the results...
String query = "select empno,ename from emp";
java.sql.ResultSet rs = stmt.executeQuery(query);
      while(rs.next()) {
java.math.BigDecimal empno = rs.getBigDecimal(1);
String ename = rs.getString(2);
System.out.println(empno + "\t" + ename);
}
      rs.close();
stmt.close();
      conn.close();
conn = null;
}

 


Using Oracle Extensions with the Oracle Thin Driver

For most extensions that Oracle provides, you can use the standard technique as described in Using Vendor Extensions to JDBC Interfaces. However, the Oracle Thin driver does not provide public interfaces for its extension methods in the following classes:

WebLogic Server provides its own interfaces to access the extension methods for those classes:

The following sections provide code samples for using the WebLogic Server interfaces for Oracle extensions. For a list of supported methods, see Tables of Oracle Extension Interfaces and Supported Methods. For more information, please refer to the Oracle documentation.

Note: You can use this process to use any of the WebLogic Server interfaces for Oracle extensions listed in the Tables of Oracle Extension Interfaces and Supported Methods. However, all but the interfaces listed above are deprecated and will be removed in a future release of WebLogic Server.

Limitations When Using Oracle JDBC Extensions

Please note the following limitations when using Oracle extensions to JDBC interfaces:

Sample Code for Accessing Oracle Extensions to JDBC Interfaces

The following code examples show how to access the WebLogic Server interfaces for Oracle extensions that are not available as public interfaces, including interfaces for:

If you selected the option to install server examples with WebLogic Server, see the JDBC examples for more code examples, typically at WL_HOME\samples\server\src\examples\jdbc, where WL_HOME is the folder where you installed WebLogic Server.

Programming with ARRAYs

In your WebLogic Server server-side applications, you can materialize an Oracle Collection (a SQL ARRAY) in a result set or from a callable statement as a Java array.

To use ARRAYs in WebLogic Server applications:

  1. Import the required classes.
  2. Get a connection and then create a statement for the connection.
  3. Get the ARRAY using a result set or a callable statement.
  4. Use the ARRAY as either a java.sql.Array or a weblogic.jdbc.vendor.oracle.OracleArray.
  5. Use the standard Java methods (when used as a java.sql.Array) or Oracle extension methods (when cast as a weblogic.jdbc.vendor.oracle.OracleArray) to work with the data.

The following sections provide more details for these actions.

Note: You can use ARRAYs in server-side applications only. You cannot use ARRAYs in remote client applications.

Import Packages to Access Oracle Extensions

Import the Oracle interfaces used in this example. The OracleArray interface is counterpart to oracle.sql.ARRAY and can be used in the same way as the Oracle interface when using the methods supported by WebLogic Server.

import java.sql.*;
import java.util.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
import weblogic.jdbc.vendor.oracle.*;

Establish the Connection

Establish the database connection using JNDI, DataSource and connection pool objects. For information, see Using a JNDI Lookup to Obtain the Connection.

// Get a valid DataSource object for a connection pool.
// Here we assume that getDataSource() takes
// care of those details.
javax.sql.DataSource ds = getDataSource(args);
// get a java.sql.Connection object from the DataSource
java.sql.Connection conn = ds.getConnection();

Getting an ARRAY

You can use the getArray() methods for a callable statement or a result set to get a Java array. You can then use the array as a java.sql.array to use standard java.sql.array methods, or you can cast the array as a weblogic.jdbc.vendor.oracle.OracleArray to use the Oracle extension methods for an array.

The following example shows how to get a java.sql.array from a result set that contains an ARRAY. In the example, the query returns a result set that contains an object column—an ARRAY of test scores for a student.

try {
  conn = getConnection(url);
stmt = conn.createStatement();
String sql = "select * from students";
//Get the result set
rs = stmt.executeQuery(sql);
  while(rs.next()) {
BigDecimal id = rs.getBigDecimal("student_id");
String name = rs.getString("name");
log("ArraysDAO.getStudents() -- Id = "+id.toString()+", Student = "+name);
//Get the array from the result set
Array scoreArray = rs.getArray("test_scores");
String[] scores = (String[])scoreArray.getArray();
for (int i = 0; i < scores.length; i++) {
log(" Test"+(i+1)+" = "+scores[i]);
}
}

Updating ARRAYs in the Database

To update an ARRAY in a database, you can Follow these steps:

  1. Create an array in the database using PL/SQL, if the array you want to update does not already exist in the database.
  2. Get the ARRAY using a result set or a callable statement.
  3. Work with the array in your Java application as either a java.sql.Array or a weblogic.jdbc.vendor.oracle.OracleArray.
  4. Update the array in the database using the setArray() method for a prepared statement or a callable statement. For example:
  5. String sqlUpdate = "UPDATE SCOTT." + tableName + " SET col1 = ?";
    conn = ds.getConnection();
    pstmt = conn.prepareStatement(sqlUpdate);
    pstmt.setArray(1, array);
    pstmt.executeUpdate();

Using Oracle Array Extension Methods

To use the Oracle extension methods for an ARRAY, you must first cast the array as a weblogic.jdbc.vendor.oracle.OracleArray. You can then make calls to the Oracle extension methods for ARRAYs. For example:

oracle.sql.Datum[] oracleArray = null;
oracleArray = ((weblogic.jdbc.vendor.oracle.OracleArray)scoreArray).getOracleArray();
String sqltype = null
sqltype = oracleArray.getSQLTypeName()

Programming with STRUCTs

In your WebLogic Server applications, you can access and manipulate objects from an Oracle database. When you retrieve objects from an Oracle database, you can cast them as either custom Java objects or as STRUCTs (java.sql.struct or weblogic.jdbc.vendor.oracle.OracleStruct). A STRUCT is a loosely typed data type for structured data which takes the place of custom classes in your applications. The STRUCT interface in the JDBC API includes several methods for manipulating the attribute values in a STRUCT. Oracle extends the STRUCT interface with several additional methods. WebLogic Server implements all of the standard methods and most of the Oracle extensions.

Note: Please note the following limitations when using STRUCTs:

To use STRUCTs in WebLogic Server applications:

  1. Import the required classes. (See Import Packages to Access Oracle Extensions.)
  2. Get a connection. (See Establish the Connection.)
  3. Use getObject to get the STRUCT.
  4. Cast the STRUCT as a STRUCT, either java.sql.Struct (to use standard methods) or weblogic.jdbc.vendor.oracle.OracleStruct (to use standard and Oracle extension methods).
  5. Use the standard or Oracle extension methods to work with the data.

The following sections provide more details for steps 3 through 5.

Getting a STRUCT

To get a database object as a STRUCT, you can use a query to create a result set and then use the getObject method to get the STRUCT from the result set. You then cast the STRUCT as a java.sql.Struct so you can use the standard Java methods. For example:

conn = ds.getConnection();
stmt = conn.createStatement();
rs   = stmt.executeQuery("select * from people");
struct = (java.sql.Struct)(rs.getObject(2)); 
Object[] attrs = ((java.sql.Struct)struct).getAttributes();

WebLogic Server supports all of the JDBC API methods for STRUCTs:

Oracle supports the standard methods as well as the Oracle extensions. Therefore, when you cast a STRUCT as a weblogic.jdbc.vendor.oracle.OracleStruct, you can use both the standard and extension methods.

Using OracleStruct Extension Methods

To use the Oracle extension methods for a STRUCT, you must cast the java.sql.Struct (or the original getObject result) as a weblogic.jdbc.vendor.oracle.OracleStruct. For example:

java.sql.Struct struct =
(weblogic.jdbc.vendor.oracle.OracleStruct)(rs.getObject(2));

WebLogic Server supports the following Oracle extensions:

Getting STRUCT Attributes

To get the value for an individual attribute in a STRUCT, you can use the standard JDBC API methods getAttributes() and getAttributes(java.util.Dictionary map), or you can use the Oracle extension method getOracleAttributes().

To use the standard method, you can create a result set, get a STRUCT from the result set, and then use the getAttributes() method. The method returns an array of ordered attributes. You can assign the attributes from the STRUCT (object in the database) to an object in the application, including Java language types. You can then manipulate the attributes individually. For example:

conn = ds.getConnection();
stmt = conn.createStatement();
rs   = stmt.executeQuery("select * from people");
//The third column uses an object data type.
//Use getObject() to assign the object to an array of values.
struct = (java.sql.Struct)(rs.getObject(2));
Object[] attrs = ((java.sql.Struct)struct).getAttributes();
String address = attrs[1]; 

In the preceding example, the third column in the people table uses an object data type. The example shows how to assign the results from the getObject method to a Java object that contains an array of values, and then use individual values in the array as necessary.

You can also use the getAttributes(java.util.Dictionary map) method to get the attributes from a STRUCT. When you use this method, you must provide a hash table to map the data types in the Oracle object to Java language data types. For example:

java.util.Hashtable map = new java.util.Hashtable();
map.put("NUMBER", Class.forName("java.lang.Integer"));
map.put("VARCHAR", Class.forName("java.lang.String"));
Object[] attrs = ((java.sql.Struct)struct).getAttributes(map);
String address = attrs[1];

You can also use the Oracle extension method getOracleAttributes() to get the attributes for a STRUCT. You must first cast the STRUCT as a weblogic.jdbc.vendor.oracle.OracleStruct. This method returns a datum array of oracle.sql.Datum objects. For example:

oracle.sql.Datum[] attrs =
((weblogic.jdbc.vendor.oracle.OracleStruct)struct).getOracleAttributes();
      oracle.sql.STRUCT address = (oracle.sql.STRUCT) attrs[1];
      Object address_attrs[] = address.getAttributes();

The preceding example includes a nested STRUCT. That is, the second attribute in the datum array returned is another STRUCT.

Using STRUCTs to Update Objects in the Database

To update an object in the database using a STRUCT, you can use the setObject method in a prepared statement. For example:

conn  = ds.getConnection();
stmt = conn.createStatement();
ps = conn.prepareStatement ("UPDATE SCHEMA.people SET EMPLNAME = ?,
EMPID = ? where EMPID = 101");
ps.setString (1, "Smith");
ps.setObject (2, struct);
ps.executeUpdate();

WebLogic Server supports all three versions of the setObject method.

Creating Objects in the Database

STRUCTs are typically used to materialize database objects in your Java application in place of custom Java classes that map to the database objects. In WebLogic Server applications, you cannot create STRUCTs that transfer to the database. However, you can use statements to create objects in the database that you can then retrieve and manipulate in your application. For example:

conn = ds.getConnection();
stmt = conn.createStatement();
cmd = "create type ob as object (ob1 int, ob2 int)"
stmt.execute(cmd);
cmd = "create table t1 of type ob";
stmt.execute(cmd);
cmd = "insert into t1 values (5, 5)"
stmt.execute(cmd);

Note: You cannot create STRUCTs in your applications. You can only retrieve existing objects from a database and cast them as STRUCTs. To create STRUCT objects in your applications, you must use a non-standard Oracle STRUCT descriptor object, which is not supported in WebLogic Server.

Automatic Buffering for STRUCT Attributes

To enhance the performance of your WebLogic Server applications that use STRUCTs, you can toggle automatic buffering with the setAutoBuffering(boolean) method. When automatic buffering is set to true, the weblogic.jdbc.vendor.oracle.OracleStruct object keeps a local copy of all the attributes in the STRUCT in their converted form (materialized from SQL to Java language objects). When your application accesses the STRUCT again, the system does not have to convert the data again.

Note: Buffering the converted attributes my cause your application to use an excessive amount of memory. Consider potential memory usage when deciding to enable or disable automatic buffering.

The following example shows how to activate automatic buffering:

 ((weblogic.jdbc.vendor.oracle.OracleStruct)struct).setAutoBuffering(true);

You can also use the getAutoBuffering() method to determine the automatic buffering mode.

Programming with REFs

A REF is a logical pointer to a row object. When you retrieve a REF, you are actually getting a pointer to a value in another table. The REF target must be a row in an object table. You can use a REF to examine or update the object it refers to. You can also change a REF so that it points to a different object of the same object type or assign it a null value.

Note: Please note the following limitations when using REFs:

To use REFs in WebLogic Server applications, follow these steps:

  1. Import the required classes. (See Import Packages to Access Oracle Extensions.)
  2. Get a database connection. (See Establish the Connection.)
  3. Get the REF using a result set or a callable statement.
  4. Cast the result as a STRUCT or as a Java object. You can then manipulate data using STRUCT methods or methods for the Java object.

You can also create and update a REF in the database.

The following sections describe these steps 3 and 4 in greater detail.

Getting a REF

To get a REF in an application, you can use a query to create a result set and then use the getRef method to get the REF from the result set. You then cast the REF as a java.sql.Ref so you can use the built-in Java method. For example:

conn = ds.getConnection();
stmt = conn.createStatement();
rs   = stmt.executeQuery("SELECT ref (s) FROM t1 s where s.ob1=5");
rs.next();
//Cast as a java.sql.Ref and get REF
ref = (java.sql.Ref) rs.getRef(1);

Note that the WHERE clause in the preceding example uses dot notation to specify the attribute in the referenced object.

After you cast the REF as a java.sql.Ref, you can use the Java API method getBaseTypeName, the only JDBC 2.0 standard method for REFs.

When you get a REF, you actually get a pointer to a value in an object table. To get or manipulate REF values, you must use the Oracle extensions, which are only available when you cast the sql.java.Ref as a weblogic.jdbc.vendor.oracle.OracleRef.

Using OracleRef Extension Methods

In order to use the Oracle extension methods for REFs, you must cast the REF as an Oracle REF. For example:

oracle.sql.StructDescriptor desc = ((weblogic.jdbc.vendor.oracle.OracleRef)ref).getDescriptor();

WebLogic Server supports the following Oracle extensions:

Getting a Value

Oracle provides two versions of the getValue() method—one that takes no parameters and one that requires a hash table for mapping return types. When you use either version of the getValue() method to get the value of an attribute in a REF, the method returns a either a STRUCT or a Java object.

The example below shows how to use the getValue() method without parameters. In this example, the REF is cast as an oracle.sql.STRUCT. You can then use the STRUCT methods to manipulate the value, as illustrated with the getAttributes() method.

oracle.sql.STRUCT student1 = 
(oracle.sql.STRUCT)((weblogic.jdbc.vendor.oracle.OracleRef)ref).getValue ();
Object attributes[] = student1.getAttributes();

You can also use the getValue(dictionary) method to get the value for a REF. You must provide a hash table to map data types in each attribute of the REF to Java language data types. For example:

java.util.Hashtable map = new java.util.Hashtable();
map.put("VARCHAR", Class.forName("java.lang.String"));
map.put("NUMBER", Class.forName("java.lang.Integer"));
oracle.sql.STRUCT result = (oracle.sql.STRUCT)
((weblogic.jdbc.vendor.oracle.OracleRef)ref).getValue (map);

Updating REF Values

When you update a REF, you can do any of the following:

To use the setValue(object) method to update a REF value, you create an object with the new values for the REF, and then pass the object as a parameter of the setValue method. For example:

STUDENT s1 = new STUDENT();
s1.setName("Terry Green");
s1.setAge(20);
((weblogic.jdbc.vendor.oracle.OracleRef)ref).setValue(s1);

When you update the value for a REF with the setValue(object) method, you actually update the value in the table to which the REF points.

To update the location to which a REF points using a prepared statement, you can follow these basic steps:

  1. Get a REF that points to the new location. You use this REF to replace the value of another REF.
  2. Create a string for the SQL command to replace the location of an existing REF with the value of the new REF.
  3. Create and execute a prepared statement.

For example:

try {
conn = ds.getConnection();
stmt = conn.createStatement();
//Get the REF.
rs   = stmt.executeQuery("SELECT ref (s) FROM t1 s where s.ob1=5");
rs.next();
ref = (java.sql.Ref) rs.getRef(1); //cast the REF as a java.sql.Ref
}
//Create and execute the prepared statement.
String sqlUpdate = "update t3 s2 set col = ? where s2.col.ob1=20";
pstmt = conn.prepareStatement(sqlUpdate);
pstmt.setRef(1, ref);
pstmt.executeUpdate();

To use a callable statement to update the location to which a REF points, you prepare the stored procedure, set any IN parameters and register any OUT parameters, and then execute the statement. The stored procedure updates the REF value, which is actually a location. For example:

conn = ds.getConnection();
stmt = conn.createStatement();
rs = stmt.executeQuery("SELECT ref (s) FROM t1 s where s.ob1=5");
rs.next();
ref1 = (java.sql.Ref) rs.getRef(1);
// Prepare the stored procedure
sql = "{call SP1 (?, ?)}";
cstmt = conn.prepareCall(sql);
// Set IN and register OUT params
cstmt.setRef(1, ref1);
cstmt.registerOutParameter(2, getRefType(), "USER.OB");
// Execute
cstmt.execute();

Creating a REF in the Database

You cannot create REF objects in your JDBC application—you can only retrieve existing REF objects from the database. However, you can create a REF in the database using statements or prepared statements. For example:

conn = ds.getConnection();
stmt = conn.createStatement();
cmd = "create type ob as object (ob1 int, ob2 int)"
stmt.execute(cmd);
cmd = "create table t1 of type ob";
stmt.execute(cmd);
cmd = "insert into t1 values (5, 5)"
stmt.execute(cmd);
cmd = "create table t2 (col ref ob)";
stmt.execute(cmd);
cmd = "insert into t2 select ref(p) from t1 where p.ob1=5";
stmt.execute(cmd);

The preceding example creates an object type (ob), a table (t1) of that object type, a table (t2) with a REF column that can point to instances of ob objects, and inserts a REF into the REF column. The REF points to a row in t1 where the value in the first column is 5.

Programming with BLOBs and CLOBs

This section contains sample code that demonstrates how to access the OracleBlob interface. You can use the syntax of this example for the OracleBlob interface, when using methods supported by WebLogic Server. See Tables of Oracle Extension Interfaces and Supported Methods.

Note: When working with BLOBs and CLOBs (referred to as "LOBs"), you must take transaction boundaries into account; for example, direct all read/writes to a particular LOB within a transaction. For additional information, refer to Oracle documentation about "LOB Locators and Transaction Boundaries" at the Oracle Web site.

Query to Select BLOB Locator from the DBMS

The BLOB Locator, or handle, is a reference to an Oracle Thin Driver BLOB:

String selectBlob = "select blobCol from myTable where blobKey = 666"

Declare the WebLogic Server java.sql Objects

The following code presumes the Connection is already established:

ResultSet rs = null; 
Statement myStatement = null;
java.sql.Blob myRegularBlob = null;
java.io.OutputStream os = null;

Begin SQL Exception Block

In this try catch block, you get the BLOB locator and access the Oracle BLOB extension.

try { 
     // get our BLOB locator.. 
     myStatement = myConnect.createStatement(); 
rs = myStatement.executeQuery(selectBlob);
while (rs.next()) {
myRegularBlob = rs.getBlob("blobCol");
}
     // Access the underlying Oracle extension functionality for
// writing. Cast to the OracleThinBlob interface to access
// the Oracle method.
     os = ((OracleThinBlob)myRegularBlob).getBinaryOutputStream();
...
     } catch (SQLException sqe) { 
System.out.println("ERROR(general SQE): " +
sqe.getMessage());
}

Once you cast to the Oracle.ThinBlob interface, you can access the BEA supported methods.

Updating a CLOB Value Using a Prepared Statement

If you use a prepared statement to update a CLOB and the new value is shorter than the previous value, the CLOB will retain the characters that were not specifically replaced during the update. For example, if the current value of a CLOB is abcdefghij and you update the CLOB using a prepared statement with zxyw, the value in the CLOB is updated to zxywefghij. To correct values updated with a prepared statement, you should use the dbms_lob.trim procedure to remove the excess characters left after the update. See the Oracle documentation for more information about the dbms_lob.trim procedure.

 


Programming with Oracle Virtual Private Databases

An Oracle Virtual Private Database (VPD) is an aggregation of server-enforced, application-defined fine-grained access control, combined with a secure application context in the Oracle 9i database server. To use VPDs in your WebLogic Server application, you would typically do the following:

  1. Create a JDBC connection pool in your WebLogic Server configuration that uses either the Oracle Thin driver or the Oracle OCI driver. See Configuring and Using WebLogic JDBC or "Creating and Configuring a JDBC Connection Pool" in the Administration Console Online Help.
  2. Note: If you are using an XA-enabled version of the JDBC driver, you must set KeepXAConnTillTxComplete=true. See "Additional XA Connection Pool Properties" in the Administration Console Online Help.

    The WebLogic jDriver for Oracle cannot propagate the ClientIdentifier, so it is ineffective to use the driver with VPDs.

  3. Create a data source in your WebLogic Server configuration that points to the connection pool. See Configuring and Using DataSources or "Creating and Configuring a JDBC Data Source" in the Administration Console Online Help.
  4. Do the following in your application:
import weblogic.jdbc.extensions.WLConnection
// get a connection from a WLS JDBC connection pool
Connection conn = ds.getConnection();
// Get the underlying vendor connection object
oracle.jdbc.OracleConnection orConn = (oracle.jdbc.OracleConnection)
(((WLConnection)conn).getVendorConnection());
// Set CLIENT_IDENTIFIER (which will be accessible from 
// USERENV naming context on the database server side)
orConn.setClientIdentifier(clientId);
/* perform application specific work, preferably using conn instead of orConn */
// clean up connection before returning to WLS JDBC connection pool
orConn.clearClientIdentifier(clientId);
// As soon as you are finished with vendor-specific calls,  
// nullify the reference to the physical connection.
orConn = null;
// close the pooled connection
conn.close();

Note: This code uses an underlying physical connection from a pooled (logical) connection. See Getting a Physical Connection from a Connection Pool for usage guidelines.

Oracle VPD with WebLogic Server 8.1SP2

Starting with WebLogic Server 8.1 SP2, WebLogic Server provides support for the oracle.jdbc.OracleConnection.setClientIdentitfier and oracle.jdbc.OracleConnection.clearClientIndentifier methods without using the underlying physical connection from a pooled connection. To use VPDs in your WebLogic Server application, you would typically do the following:

import weblogic.jdbc.vendor.oracle.OracleConnection;
// get a connection from a WLS JDBC connection pool
Connection conn = ds.getConnection();
// cast to the Oracle extension and set CLIENT_IDENTIFIER
// (which will be accessible from USERENV naming context on
// the database server side)
((weblogic.jdbc.vendor.oracle.OracleConnection)conn).setClientIdentifier(clientId);
/* perform application specific work */
// clean up connection before returning to WLS JDBC connection pool
((OracleConnection)conn).clearClientIdentifier(clientId);
// close the connection
conn.close();

 


Support for Vendor Extensions Between Versions of WebLogic Server Clients and Servers

Because the way WebLogic Server supports vendor JDBC extensions was changed in WebLogic Server 8.1, interoperability between versions of client and servers is affected.

When a WebLogic Server 8.1 client interacts with a WebLogic Server 7.0 or earlier server, Oracle extensions are not supported. When the client application tries to cast the JDBC objects to the Oracle extension interfaces, it will get a ClassCastException. However, when a WebLogic Server 7.0 or earlier client interacts with a WebLogic Server 8.1 server, Oracle extensions are supported.

This applies to the following Oracle extension interfaces:

Note: Standard JDBC interfaces are supported regardless of the client or server version.

 


Tables of Oracle Extension Interfaces and Supported Methods

In previous releases of WebLogic Server, only the JDBC extensions listed in the following tables were supported. The current release of WebLogic Server supports most extension methods exposed as a public interface in the vendor's JDBC driver. See Using Vendor Extensions to JDBC Interfaces for instructions for using vendor extensions. Because the new internal mechanism for supporting vendor extensions does not rely on the previous implementation, several interfaces are no longer needed and are deprecated. These interfaces will be removed in a future release of WebLogic Server. See Table 5-6. BEA encourages you to use the alternative interface listed in the table.

Table 5-6 Deprecated Interfaces for Oracle JDBC Extensions

Deprecated Interface (supported in WebLogic Server 7.0 and earlier)

Instead, use this interface from Oracle (supported in WebLogic Server version 8.1 and later)

weblogic.jdbc.vendor.oracle.
OracleConnection

oracle.jdbc.OracleConnection

weblogic.jdbc.vendor.oracle.
OracleStatement

oracle.jdbc.OracleStatement

weblogic.jdbc.vendor.oracle.
OracleCallableStatement

oracle.jdbc.OracleCallableStatement

weblogic.jdbc.vendor.oracle.
OraclePreparedStatement

oracle.jdbc.OraclePreparedStatement

weblogic.jdbc.vendor.oracle.
OracleResultSet

oracle.jdbc.OracleResultSet

The interfaces listed in Table 5-7 are still valid because Oracle does not provide interfaces to access these extension methods.

Table 5-7 Oracle Interfaces with Continued Support in WebLogic Server

Oracle Interface

weblogic.jdbc.vendor.oracle.OracleArray

weblogic.jdbc.vendor.oracle.OracleRef

weblogic.jdbc.vendor.oracle.OracleStruct

weblogic.jdbc.vendor.oracle.OracleThinClob

weblogic.jdbc.vendor.oracle.OracleThinBlob

The following tables describe the Oracle interfaces and supported methods you use with the Oracle Thin Driver (or another driver that supports these methods) to extend the standard JDBC (java.sql.*) interfaces.

Table 5-8 OracleConnection Interface

Extends

Method Signature

OracleConnection
extends java.sql.Connection

(This interface is deprecated. See Table 5-6.)


void clearClientIdentifier(String s) 
throws java.sql.SQLException;
boolean getAutoClose() 
throws java.sql.SQLException;
String getDatabaseProductVersion()
throws java.sql.SQLException;
String getProtocolType() throws
java.sql.SQLException;
String getURL() throws java.sql.SQLException;
String getUserName()
throws java.sql.SQLException;
boolean getBigEndian() 
throws java.sql.SQLException;
boolean getDefaultAutoRefetch() throws
java.sql.SQLException;
boolean getIncludeSynonyms()
throws java.sql.SQLException;
boolean getRemarksReporting()
throws java.sql.SQLException;
boolean getReportRemarks() 
throws java.sql.SQLException;

OracleConnection
extends java.sql.Connection

(continued)

(This interface is deprecated. See Table 5-6.)


boolean getRestrictGetTables()
throws java.sql.SQLException;
boolean getUsingXAFlag()
throws java.sql.SQLException;
boolean getXAErrorFlag() 
throws java.sql.SQLException;
boolean isCompatibleTo816()
throws java.sql.SQLException;
(Deprecated)
byte[] getFDO(boolean b) 
throws java.sql.SQLException;
int getDefaultExecuteBatch() throws 
java.sql.SQLException;
int getDefaultRowPrefetch() 
throws java.sql.SQLException;
int getStmtCacheSize() 
throws java.sql.SQLException;
java.util.Properties getDBAccessProperties()
throws java.sql.SQLException;
short getDbCsId() throws java.sql.SQLException;
short getJdbcCsId() throws java.sql.SQLException;
short getStructAttrCsId() 
throws java.sql.SQLException;
short getVersionNumber() 
throws java.sql.SQLException;
void archive(int i, int j, String s) 
throws java.sql.SQLException;

OracleConnection
extends java.sql.Connection

(continued)

(This interface is deprecated. See Table 5-6.)


void close_statements() 
throws java.sql.SQLException;
void initUserName() throws java.sql.SQLException;
void logicalClose() throws java.sql.SQLException;
void needLine() throws java.sql.SQLException;
void printState() throws java.sql.SQLException;
void registerSQLType(String s, String t) 
throws java.sql.SQLException;
void releaseLine() throws java.sql.SQLException;  
void removeAllDescriptor() 
throws java.sql.SQLException;
void removeDescriptor(String s) 
throws java.sql.SQLException;
void setAutoClose(boolean on) throws
java.sql.SQLException;
void setClientIdentifier(String s) 
throws java.sql.SQLException;
void clearClientIdentifier(String s) throws java.sql.SQLException;
void setDefaultAutoRefetch(boolean b)
throws java.sql.SQLException;
void setDefaultExecuteBatch(int i) 
throws java.sql.SQLException;
void setDefaultRowPrefetch(int i) 
throws java.sql.SQLException;
void setFDO(byte[] b) 
throws java.sql.SQLException;
void setIncludeSynonyms(boolean b) 
throws java.sql.SQLException;

OracleConnection
extends java.sql.Connection

(continued)

(This interface is deprecated. See Table 5-6.)


void setPhysicalStatus(boolean b) 
throws java.sql.SQLException;
void setRemarksReporting(boolean b) 
throws java.sql.SQLException;
void setRestrictGetTables(boolean b) 
throws java.sql.SQLException;
void setStmtCacheSize(int i) 
throws java.sql.SQLException;
void setStmtCacheSize(int i, boolean b) 
throws java.sql.SQLException;
void setUsingXAFlag(boolean b) 
throws java.sql.SQLException;
void setXAErrorFlag(boolean b) 
throws java.sql.SQLException;
void shutdown(int i) 
throws java.sql.SQLException;
void startup(String s, int i)
throws java.sql.SQLException;


 

Table 5-9 OracleStatement Interface

Extends

Method Signature

OracleStatement
extends java.sql.statement

(This interface is deprecated. See Table 5-6.)


String getOriginalSql() 
throws java.sql.SQLException;
String getRevisedSql() 
throws java.sql.SQLException;
(Deprecated in Oracle 8.1.7, removed in Oracle 9i.)
boolean getAutoRefetch() 
throws java.sql.SQLException;
boolean is_value_null(boolean b, int i) 
throws java.sql.SQLException;
byte getSqlKind() 
throws java.sql.SQLException;
int creationState() 
throws java.sql.SQLException;
int getAutoRollback() 
throws java.sql.SQLException;
(Deprecated)
int getRowPrefetch() 
throws java.sql.SQLException;
int getWaitOption() 
throws java.sql.SQLException;
(Deprecated)
int sendBatch() 
throws java.sql.SQLException;

OracleStatement
extends java.sql.statement

(continued)

(This interface is deprecated. See Table 5-6.)


void clearDefines() 
throws java.sql.SQLException;
void defineColumnType(int i, int j) 
throws java.sql.SQLException;
void defineColumnType(int i, int j, String s)
throws java.sql.SQLException;
void defineColumnType(int i, int j, int k) 
throws java.sql.SQLException;
void describe() 
throws java.sql.SQLException;
void setAutoRefetch(boolean b) 
throws java.sql.SQLException;
void setAutoRollback(int i) 
throws java.sql.SQLException;
(Deprecated)
void setRowPrefetch(int i) 
throws java.sql.SQLException;
void setWaitOption(int i) 
throws java.sql.SQLException;
(Deprecated)


 

Table 5-10 OracleResultSet Interface

Extends

Method Signature

OracleResultSet
extends java.sql.ResultSet

(This interface is deprecated. See Table 5-6.)


boolean getAutoRefetch() throws java.sql.SQLException;
int getFirstUserColumnIndex() 
throws java.sql.SQLException;
void closeStatementOnClose() 
throws java.sql.SQLException;
void setAutoRefetch(boolean b) 
throws java.sql.SQLException;
java.sql.ResultSet getCursor(int n) 
throws java.sql.SQLException;
java.sql.ResultSet getCURSOR(String s) 
throws java.sql.SQLException;


 

.

Table 5-11 OracleCallableStatement Interface

Extends

Method Signature

OracleCallableStatement
extends
java.sql.CallableStatement

(This interface is deprecated. See Table 5-6.)


void clearParameters() 
throws java.sql.SQLException;
void registerIndexTableOutParameter(int i, 
int j, int k, int l)
throws java.sql.SQLException;
void registerOutParameter
(int i, int j, int k, int l)
throws java.sql.SQLException;
java.sql.ResultSet getCursor(int i) 
throws java.sql.SQLException;
java.io.InputStream getAsciiStream(int i)
throws java.sql.SQLException;
java.io.InputStream getBinaryStream(int i)
throws java.sql.SQLException;
java.io.InputStream getUnicodeStream(int i)
throws java.sql.SQLException;


 

.

Table 5-12 OraclePreparedStatement Interface

Extends

Method Signature

OraclePreparedStatement
extends
OracleStatement and java.sql. PreparedStatement

(This interface is deprecated. See Table 5-6.)


int getExecuteBatch() 
throws java.sql.SQLException;
void defineParameterType(int i, int j, int k) 
throws java.sql.SQLException;
void setDisableStmtCaching(boolean b) 
throws java.sql.SQLException;
void setExecuteBatch(int i) 
throws java.sql.SQLException;
void setFixedCHAR(int i, String s) 
throws java.sql.SQLException;
void setInternalBytes(int i, byte[] b, int j)
throws java.sql.SQLException;


 

Table 5-13 OracleArray Interface

Extends

Method Signature

OracleArray
extends java.sql.Array


public ArrayDescriptor getDescriptor() 
throws java.sql.SQLException;
public Datum[] getOracleArray() 
throws SQLException;
public Datum[] getOracleArray(long l, int i) 
throws SQLException;
public String getSQLTypeName()
throws java.sql.SQLException;
public int length()
throws java.sql.SQLException;
public double[] getDoubleArray()
throws java.sql.SQLException;
public double[] getDoubleArray(long l, int i)
throws java.sql.SQLException;
public float[] getFloatArray()
throws java.sql.SQLException;
public float[] getFloatArray(long l, int i)
throws java.sql.SQLException;
public int[] getIntArray()
throws java.sql.SQLException;
public int[] getIntArray(long l, int i)
throws java.sql.SQLException;
public long[] getLongArray()
throws java.sql.SQLException;
public long[] getLongArray(long l, int i)
throws java.sql.SQLException;

OracleArray
extends java.sql.Array

(continued)

public short[] getShortArray()
throws java.sql.SQLException;
public short[] getShortArray(long l, int i)
throws java.sql.SQLException;
public void setAutoBuffering(boolean flag)
throws java.sql.SQLException;
public void setAutoIndexing(boolean flag)
throws java.sql.SQLException;
public boolean getAutoBuffering()
throws java.sql.SQLException;
public boolean getAutoIndexing()
throws java.sql.SQLException;
public void setAutoIndexing(boolean flag, int i)
throws java.sql.SQLException;


 

Table 5-14 OracleStruct Interface

Extends

Method Signature

OracleStruct
extends java.sql.Struct


public Object[] getAttributes() 
throws java.sql.SQLException;
public Object[] getAttributes(java.util.Dictionary map)
throws java.sql.SQLException;
public Datum[] getOracleAttributes() 
throws java.sql.SQLException;
public oracle.sql.StructDescriptor getDescriptor() 
throws java.sql.SQLException;
public String getSQLTypeName() 
throws java.sql.SQLException;
public void setAutoBuffering(boolean flag) 
throws java.sql.SQLException;
public boolean getAutoBuffering() 
throws java.sql.SQLException;


 

Table 5-15 OracleRef Interface

Extends

Method Signature

OracleRef
extends java.sql.Ref


public String getBaseTypeName() 
throws SQLException;
public oracle.sql.StructDescriptor getDescriptor() 
throws SQLException;
public oracle.sql.STRUCT getSTRUCT() 
throws SQLException;
public Object getValue() 
throws SQLException;
public Object getValue(Map map) 
throws SQLException;
public void setValue(Object obj) 
throws SQLException;


 

Table 5-16 OracleThinBlob Interface

Extends

Method Signature

OracleThinBlob
extends java.sql.Blob

int getBufferSize()throws java.sql.Exception
int getChunkSize()throws java.sql.Exception
int putBytes(long, int, byte[])throws java.sql.Exception
int getBinaryOutputStream()throws java.sql.Exception


 

Table 5-17 OracleThinClob Interface

Extends

Method Signature

OracleThinClob
extends java.sql.Clob

public OutputStream getAsciiOutputStream()
throws java.sql.Exception;
public Writer getCharacterOutputStream()
throws java.sql.Exception;
public int getBufferSize() throws java.sql.Exception;
public int getChunkSize() throws java.sql.Exception;
public char[] getChars(long l, int i)
throws java.sql.Exception;
public int putChars(long start, char myChars[])
throws java.sql.Exception;
public int putString(long l, String s)
throws java.sql.Exception;


 

 

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