Connection Pooling and JSP Custom Tag Library - is code (inside) the best way/correc?

Question

Hi, can anyone advise as to whether my tag library code (based
on Apache Jakarta Project) will actually achieve connection
pooling functionality across my entire JSP based application? I
am slightly concerned that my OracleConnectionCacheImpl object
may exist multiple times, hence rendering my conection pooling
attempt useless.
package com.solved.tag.dbtags.connection;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import javax.servlet.jsp.tagext.TagSupport;
import javax.servlet.jsp.JspTagException;
import javax.sql.DataSource;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import oracle.jdbc.pool.OracleConnectionCacheImpl;
* <p>JSP tag connection, used to get a
* java.sql.Connection object.</p>
* <p>JSP Tag Lib Descriptor
* <pre>
* &lt;name>connection&lt;/name>
&lt;tagclass>com.solved.tag.dbtags.connection.ConnectionTag&lt;/t
agclass>
* &lt;bodycontent>JSP&lt;/bodycontent>
&lt;teiclass>com.solved.tag.dbtags.connection.ConnectionTEI&lt;/t
eiclass>
* &lt;info>Opens a connection based on a jndiName.&lt;/info>
* &lt;attribute>
* &lt;name>id&lt;/name>
* &lt;required>true&lt;/required>
* &lt;rtexprvalue>false&lt;/rtexprvalue>
* &lt;/attribute>
* </pre>
* @author Matt Shannon
public class ConnectionTag extends TagSupport {
static private OracleConnectionCacheImpl cache = null;
public int doStartTag() throws JspTagException {
try {
Connection conn = null;
if (cache == null) {
try {
InitialContext ic = new InitialContext();
DataSource ds = (DataSource) ic.lookup
("jdbc/pool/OracleCache");
cache = (OracleConnectionCacheImpl)ds;
catch (NamingException ne) {
throw new JspTagException(ne.toString());
conn = cache.getConnection();
pageContext.setAttribute(getId(),conn);
catch (SQLException e) {
throw new JspTagException(e.toString());
return EVAL_BODY_INCLUDE;
package com.solved.tag.dbtags.connection;
import java.sql.Connection;
import java.sql.SQLException;
import javax.servlet.jsp.tagext.TagSupport;
* <p>JSP tag closeconnection, used to close the
* specified java.sql.Connection.<p>
* <p>JSP Tag Lib Descriptor
* <pre>
* &lt;name>closeConnection&lt;/name>
&lt;tagclass>com.solved.tag.dbtags.connection.CloseConnectionTag&
lt;/tagclass>
* &lt;bodycontent>empty&lt;/bodycontent>
* &lt;info>Close the specified connection. The "conn"
attribute is the name of a
* connection object in the page context.&lt;/info>
* &lt;attribute>
* &lt;name>conn&lt;/name>
* &lt;required>true&lt;/required>
* &lt;rtexprvalue>false&lt;/rtexprvalue>
* &lt;/attribute>
* </pre>
* @author Matt Shannon
* @see ConnectionTag
public class CloseConnectionTag extends TagSupport {
private String _connId = null;
* The "conn" attribute is the name of a
* page context object containing a
* java.sql.Connection.
* @param connectionId
* attribute name of the java.sql.Connection to
close.
* @see ConnectionTag
public void setConn(String connectionId) {
_connId = connectionId;
public int doStartTag() {
try {
Connection conn = (Connection)pageContext.getAttribute
(_connId);
conn.close();
} catch (SQLException e) {
// failing to close a connection is not fatal
e.printStackTrace();
return EVAL_BODY_INCLUDE;
public void release() {
_connId = null;
package com.solved.tag.dbtags.connection;
import javax.servlet.jsp.tagext.TagData;
import javax.servlet.jsp.tagext.TagExtraInfo;
import javax.servlet.jsp.tagext.VariableInfo;
* TagExtraInfo for the connection tag. This
* TagExtraInfo specifies that the ConnectionTag
* assigns a java.sql.Connection object to the
* "id" attribute at the end tag.
* @author Matt Shannon
* @see ConnectionTag
public class ConnectionTEI extends TagExtraInfo {
public final VariableInfo[] getVariableInfo(TagData data)
return new VariableInfo[]
new VariableInfo(
data.getAttributeString("id"),
"java.sql.Connection",
true,
VariableInfo.AT_END
data-sources.xml:
<?xml version="1.0"?>
<!DOCTYPE data-sources PUBLIC "Orion data-
sources" "http://xmlns.oracle.com/ias/dtds/data-sources.dtd">
<data-sources>
<data-source
class="oracle.jdbc.pool.OracleConnectionCacheImpl"
name="jdbc/pool/OracleCache"
location="jdbc/pool/OracleCache"
url="jdbc:oracle:thin:@oracle1:1521:pdev"
>
<property name="maxLimit" value="15" />
<property name="cacheScheme" value="2" />
<property name="user" value="console" />
<property name="password" value="console" />
<description>
This DataSource is using an Oracle-native DataSource Class so as
to allow Oracle Specific extensions.
A getConnection() call on this DataSource will return
oracle.jdbc.driver.OracleConnection.
The connection returned is a logical connection.
The caching scheme in place is Fixed Wait. Refer below to
possible values.
Dynamic 1
Fixed Wait 2
Fixed Return Null 3
</description>
</data-source>
</data-sources>
many thanks,
Matt.

Answer 1

Hi. Show me your pool definition.
Joe
Ramamurthy wrote:
I am using the jsp custom tag library from BEA called sqltags.tld which came with Weblogic 5.1. Currently I am using Weblogic6.1 sp2 on Solaris.
I have created a Connection Pool for Sybase database using the driver com.sybase.jdbc.SybDriver.
When I created jsp page to connect to the connection pool using sqltags custom tag library, I am getting the error
"javax.servlet.jsp.JspException: Failed to write body content
at weblogic.taglib.sql.ConnectionTag.doAfterBody(ConnectionTag.java:43)
at jsp_servlet.__hubwcdata._jspService(__sampletest.java:1014)"
After this message, whenever I try to access the same jsp page I am getting the message
"javax.servlet.jsp.JspException: Failed to load JDBC driver: weblogic.jdbc.pool.D
river
at weblogic.taglib.sql.ConnectionTag.doStartTag(ConnectionTag.java:34)
at jsp_servlet.__hubwcdata._jspService(__sampletest.java:205)".
Can you please help me the reason why this problem is happening and how to fix this ?
This problem doexn't happen consistently. This occurs once in a while.
I tried to increase Login delay Seconds parameter in the Connection Pool to 15 sec. It didn't help me much.
Thanks for your help !!!
Ram