"mastering tomcat development" servlet code problem

[phtobias]

I try to follow a servlet example [Chapter_5/SQLSampleServlet.java] in the book "mastering tomcat development" by Peter Harrison/Ian McFarland, but run into a problem.

Your help is greatly appreciated. Many Thanks.

yi-ren

My setup:
-----------------------------------------------------------
Apache Tomcat/4.1.18 and httpd/2.0.47 using connector mod_jk-2.0.43.so

[java version "1.4.2"]
javac -classpath common/lib/servlet.jar webapps/examples/WEB-INF/classes/SQLSampleServlet.java

http://localhost:8080/examples/servlet/SQLSampleServlet

-----------------------------------------------------------

Here is the error messages:
----------------------------------------------------
javax.servlet.UnavailableException
at SQLSampleServlet.init(SQLSampleServlet.java:22)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:934)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:666)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2415)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:432)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:386)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:534)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:530)
at java.lang.Thread.run(Thread.java:534)
----------------------------------------------------


Here is the part of the code that causes the problem:
----------------------------------------------------
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;

public class SQLSampleServlet extends HttpServlet{
private Connection con;
public void init(ServletConfig config) throws ServletException
{
String driver = config.getInitParameter("database-driver-class"
String jdbcurl = config.getInitParameter("database-url"
String login = config.getInitParameter("database-login"
String password = config.getInitParameter("database-password"
try
{
//error comes from here
Class.forName(driver); // Load the driver
con = DriverManager.getConnection(jdbcurl, login, password);
}
catch (Exception e)
{
throw new UnavailableException(e.getMessage());
}
}

public void doGet(HttpServletRequest request, HttpServletResponse response) {
//This part works OK.
}
}

 

[phtobias]

I think the problem is at web.xml. I have to give the <init-param> first.

sorry for the long write.

Post again if I make it work.

yi-ren

 

[phtobias]

It is kind of half work, half failure.

I added the <init-param> (see attached) into the web.xml and now it knows the variables driver/jdbcurl/login/passowrd. The problem is that it still said &quot;javax.servlet.UnavailableException: org.gjt.mm.mysql.Driver&quot;.

Can anyone give me a hint how to install org.gjt.mm.mysql.Driver onto the tomcat?

yi-ren

----------------------------------------------------------
Added to web.xml
----------------------------------------------------------
<servlet>
<servlet-name>SQL</servlet-name>
<servlet-class>SQLSampleServlet</servlet-class>
<init-param>
<param-name>persistence.type</param-name>
<param-value>pooled</param-value>
</init-param>
<init-param>
<param-name>database-driver-class</param-name>
<param-value>org.gjt.mm.mysql.Driver</param-value>
<!--param-value>org.postgresql.Driver</param-value-->
</init-param>
<init-param>
<param-name>database-url</param-name>
<param-value>jdbc:mysql://localhost/tomcatbook</param-value>
<!--param-value>jdbcostgresql://localhost/tomcatbook</param-value-->
</init-param>
<init-param>
<param-name>database-login</param-name>
<param-value>tomcatbook</param-value>
</init-param>
<init-param>
<param-name>database-password</param-name>
<param-value>badpassword</param-value>
</init-param>
</servlet>

<servlet-mapping>
<servlet-name>SQL</servlet-name>
<url-pattern>/servelt/sql</url-pattern>
</servlet-mapping>