Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

problem using my user defined class in my JSP page

1 view
Skip to first unread message

LMac...@gmail.com

unread,
Apr 17, 2005, 11:24:33 PM4/17/05
to
I tried to define a class and use it in my JSP page, but i'm running
into some problems...

here is the JSP code:
=============================================================
<%@ page
import = "java.io.*, java.lang.*, java.sql.*, bkwrmspackage.*"
%>

<jsp:useBean id="user" class="bkwrmspackage.UserData" scope="session"/>
<jsp:setProperty name="user" property="*"/>

<HTML>
<HEAD><TITLE>BookWorms - Authenticating...</TITLE></HEAD>
<BODY>

<%
DbClass dbinstance;
int status = 0;
status = dbinstance.verifyUser(user.getUsername(),
user.getUpassword());

if(status == 1){
out.println("you have logged in successfully\n");
}else if(status == -1){
out.println("login info invalid\n");
}else if(status == -2){
out.println("there was an unknown error during login,
try again\n");

}
%>

here is the code for the class:
=============================================================
package bkwrmspackage;

import java.sql.*;
import java.lang.*;
import java.io.*;

public class DbClass {

public int verifyUser(String username, String password) {
Connection dbconn;
PreparedStatement sql;

try{//try to load the mysql driver
Class.forName("org.gjt.mm.mysql.Driver");
try{
//establish a connection to the database

dbconn=DriverManager.getConnection("jdbc:mysql://localhost/group10","group10","pass");

Statement statement = dbconn.createStatement();
String query = "SELECT * FROM members WHERE username =
" + username;
ResultSet rs;
rs = statement.executeQuery(query);

while(rs.next()){
String dpass = rs.getString("upassword");

if(dpass.equals(password)){
return 1;
}
return -1;
}

}

catch (SQLException s){
return -2;
}
}
catch (ClassNotFoundException err){
return -2;
}
return -2;
}
}


here is the error message:
=============================================================
type Exception report

message

description The server encountered an internal error () that prevented
it from fulfilling this request.

exception

org.apache.jasper.JasperException: Unable to compile class for JSP

An error occurred at line: 11 in the jsp file: /group10/auth.jsp

Generated servlet error:
[javac] Since fork is true, ignoring compiler setting.
[javac] Compiling 1 source file
[javac] Since fork is true, ignoring compiler setting.
[javac]
/usr/jakarta-tomcat-4.1.24/work/Standalone/localhost/_/group10/auth_jsp.java:73:
variable dbinstance might not have been initialized
[javac] status = dbinstance.verifyUser(user.getUsername(),
user.getUpassword());
[javac] ^
[javac] 1 error

at
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:130)
at
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:293)
at
org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:353)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:370)
at
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:473)
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:190)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
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.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$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at
org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at
org.apache.catalina.core.StandardPipeline$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:594)
at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
at
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
at java.lang.Thread.run(Thread.java:536)

I'm not sure why i keep getting this error. I've even tried changing:
"DbClass dbinstance;" to "DbClass dbinstance = new DbClass();" and I
get the following error:
============================================================
type Exception report

message

description The server encountered an internal error () that prevented
it from fulfilling this request.

exception

org.apache.jasper.JasperException
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:254)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
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.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$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at
org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at
org.apache.catalina.core.StandardPipeline$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:594)
at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
at
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
at java.lang.Thread.run(Thread.java:536)

root cause

javax.servlet.ServletException
at
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:536)
at org.apache.jsp.auth_jsp._jspService(auth_jsp.java:100)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:210)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
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.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$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at
org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at
org.apache.catalina.core.StandardPipeline$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:594)
at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
at
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
at java.lang.Thread.run(Thread.java:536)

i have NO IDEA what this error is trying to tell me...can anyone help?

Thanks in advance,
--Lucas

SMC

unread,
Apr 18, 2005, 12:19:55 AM4/18/05
to
On Mon, 18 Apr 2005 13:24:33 +1000, LMachado1 wrote:

> I tried to define a class and use it in my JSP page, but i'm running
> into some problems...
>
> here is the JSP code:
> ============================================================= <%@ page
> import = "java.io.*, java.lang.*, java.sql.*, bkwrmspackage.*"
> %>
>
> <jsp:useBean id="user" class="bkwrmspackage.UserData" scope="session"/>
> <jsp:setProperty name="user" property="*"/>
>
> <HTML>
> <HEAD><TITLE>BookWorms - Authenticating...</TITLE></HEAD> <BODY>
>
> <%
> DbClass dbinstance;
> int status = 0;
> status = dbinstance.verifyUser(user.getUsername(),
> user.getUpassword());

You declare dbinstance (of type DbClass) but you don't create an instance
of it before calling the verifyUser() method.

You need:

DbClass dbinstance = new DbClass();

Or else you can make your verifyUser method static, in which case you
could just do

status = DbClass.verifyUser(user.getUsername());


--
Sean

LMac...@gmail.com

unread,
Apr 18, 2005, 10:17:15 AM4/18/05
to


sorry, there is so much stuff in my post you may have missed that
part... I've tried making it static, and that works, but I'd rather not
make it a static function if I can help it...

--Lucas

0 new messages