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Posted to users@tomcat.apache.org by António Casqueiro <ac...@yahoo.co.uk> on 2002/06/05 19:07:53 UTC
ClassCastException OraclePreparedStatement
Connection Pool configuration
<Context path="/NASApp" docBase="NASApp"
reloadable="true">
<Resource name="jdbc/pool" auth="Container"
type="javax.sql.DataSource"/>
<ResourceParams name="jdbc/pool">
<parameter>
<name>user</name>
<value>DES</value>
</parameter>
<parameter>
<name>password</name>
<value>DES</value>
</parameter>
<parameter>
<name>driverClassName</name>
<value>oracle.jdbc.driver.OracleDriver</value>
</parameter>
<parameter>
<name>driverName</name>
<value>jdbc:oracle:oci8:MyUser/MyPass@MyDatabase</value>
</parameter>
</ResourceParams>
</Context>
Server.xml
Jar with the driver
<TOMCAT>\common\lib\classes12.jar
Get a connection from the Connection Pool
// Obtain our environment naming context
javax.naming.Context initCtx = new InitialContext();
javax.naming.Context context = (Context)
initCtx.lookup("java:comp/env");
System.out.println("TRY CONNECT");
javax.sql.DataSource ds =
(javax.sql.DataSource)context.lookup("jdbc/pool");
connection = ds.getConnection();
System.out.println("CONNECTED");
Cast the PreparedStatement to OraclePreparedStatement
import oracle.jdbc.driver.OraclePreparedStatement;
(...)
pstat =
connection.getJDBCPreparedStatement(query);
pstat.setFetchSize(fetchSize);
System.out.println( "pstat.getClass()"
+ pstat.getClass() );
if(pstat instanceof
oracle.jdbc.driver.OraclePreparedStatement) {
System.out.println("Yes -
STATprepOracle");
}
else {
System.out.println("No -
STATprepOracle");
if(pstat instanceof
oracle.jdbc.driver.OracleStatement) {
System.out.println("Yes -
STAToracle");
}
if(pstat instanceof
java.sql.Statement) {
System.out.println("Yes -
STATsql");
}
if(pstat instanceof
java.sql.PreparedStatement) {
System.out.println("Yes -
STATprepSql");
}
Class c = pstat.getClass();
System.out.println( "c.getName():
" + c.getName() );
System.out.println(
"c.getPackage(): " + c.getPackage() );
System.out.println(
"c.getClassLoader(): " + c.getClassLoader() );
}
oracle.jdbc.driver.OraclePreparedStatement ostat =
null;
try {
ostat =
(oracle.jdbc.driver.OraclePreparedStatement) pstat;
}
catch (Throwable e) {
e.printStackTrace();
}
ostat.defineColumnType(CODIGOPERFIL_ROW,
Types.VARCHAR);
ostat.defineColumnType(TIPOERROCLO_ROW,
Types.VARCHAR);
Console output
TRY CONNECT
CONNECTED
pstat.getClass()class
oracle.jdbc.driver.OraclePreparedStatement
No - STATprepOracle
Yes - STATsql
Yes - STATprepSql
c.getName():
oracle.jdbc.driver.OraclePreparedStatement
c.getPackage(): package oracle.jdbc.driver
c.getClassLoader(): StandardClassLoader
available:
Extension[javax.mail, implementationVendor=Sun
Microsystems, Inc., implementationVendorId=com.sun,
implementationVersion=1.2, specificationVendor=Sun
Microsystems, Inc., specificationVersion=1.2]
delegate: false
repositories:
file:D:\java\tomcat40\common\classes\
file:D:\java\tomcat40\common\lib\activation.jar
file:D:\java\tomcat40\common\lib\classes12.jar
file:D:\java\tomcat40\common\lib\crimson.jar
file:D:\java\tomcat40\common\lib\jaxp.jar
file:D:\java\tomcat40\common\lib\jdbc2_0-stdext.jar
file:D:\java\tomcat40\common\lib\jta-spec1_0_1.jar
file:D:\java\tomcat40\common\lib\ldap.jar
file:D:\java\tomcat40\common\lib\mail.jar
file:D:\java\tomcat40\common\lib\naming-common.jar
file:D:\java\tomcat40\common\lib\naming-resources.jar
file:D:\java\tomcat40\common\lib\servlet.jar
file:D:\java\tomcat40\common\lib\tyrex-0.9.7.0.jar
required:
----------> Parent Classloader:
sun.misc.Launcher$AppClassLoader@71732b
java.lang.ClassCastException:
oracle.jdbc.driver.OraclePreparedStatement
(...)
at
org.apache.jasper.runtime.HttpJspBase.service(Unknown
Source)
at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(Unknown
Source)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(Unknown
Source)
at
org.apache.jasper.servlet.JspServlet.service(Unknown
Source)
at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown
Source)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown
Source)
at
org.apache.catalina.core.StandardWrapperValve.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invokeNext(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invoke(Unknown
Source)
at
org.apache.catalina.core.ContainerBase.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardContextValve.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invokeNext(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invoke(Unknown
Source)
at
org.apache.catalina.core.ContainerBase.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardContext.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardHostValve.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invokeNext(Unknown
Source)
at
org.apache.catalina.valves.AccessLogValve.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invokeNext(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invoke(Unknown
Source)
at
org.apache.catalina.core.ContainerBase.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardEngineValve.invoke(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invokeNext(Unknown
Source)
at
org.apache.catalina.core.StandardPipeline.invoke(Unknown
Source)
at
org.apache.catalina.core.ContainerBase.invoke(Unknown
Source)
at
org.apache.catalina.connector.http.HttpProcessor.process(Unknown
Source)
at
org.apache.catalina.connector.http.HttpProcessor.run(Unknown
Source)
at java.lang.Thread.run(Thread.java:484)
java.lang.NullPointerException
- - - - - - - -
- - QUESTION - -
- - - - - - - -
I'm trying to configure a Connection Pool in Tomcat 4
to Oracle 8.1.7 database.
Everything works fine if I don't cast my
PreparedStatement to OraclePreparedStatement, to take
advantage of the "defineColumnType" method (this will
save 2 roundtrips to the RDBMS when executing the
query [that's what the documentation says]).
To figure out what class do I have, do the folowing:
> => System.out.println( "pstat.getClass()" +
pstat.getClass() );
and I get the output
=> pstat.getClass()class
oracle.jdbc.driver.OraclePreparedStatement
If I use JBuilder in debug and "Evaluate" the "pstat"
object I also see a
"oracle.jdbc.driver.OraclePreparedStatement", so
probably the
"oracle.jdbc.driver.OraclePreparedStatement" was
casted to "java.sql.PreparedStatement" right?
How can I fix it? Maybe it has something to do with
the "tyrex" connection pool. Is there another way to
create a connection pool to Oracle 8.1.7 in Tomcat?
How? Thanks
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