Обсуждение: couldn't load DB driver : null
Before, I can connect database both from applet or
servlet.But today, when I try to connect database from
applet or servlet, there was a problem.
By servlet the error message is : "Couldn't load DB
driver :null".
By applet, in the browser just appear "Connecting to
database ", and in the status bar is a message "Applet
myapplet org/postgresql/jdbc2/Resultset".
Help me please......
The SERVLET code :
import java.io.*;import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class myServlet extends HttpServlet
{ public void doGet(HttpServletRequest req,
HttpServletResponse res) throws ServletException, IOException { Connection con = null;Statement stmt = null;
ResultSet rs = null; res.setContentType("text/html"); PrintWriter out = res.getWriter();
try[ Class.forName("org.postgresql.Driver"); con =
DriverManager.getConnection("jdbc:postgresql:myDB",
"me", "pass"); stmt = con.createStatement(); rs = stmt.executeQuery("select k_id,
k_name, date
from myTable");
out.println("<HTML><HEAD><TITLE>KAMOKU</TITLE></HEAD>"); out.println("<BODY><FONT
COLOR='RED'><H3><BR>TEST
SERVLET & JDBC</H3><BR></FONT>"); out.println("SELECT id, name, date FROM
kamoku<BR><BR> "); out.println("<UL>"); while(rs.next()){ out.println("<LI>" +
rs.getString("k_id")+" "+
rs.getString("k_name") + " " + rs.getDate("date")); } out.println("<UL>");
out.println("</BODY></HTML>"); } catch(ClassNotFoundException e) { out.println("Couldn't
loadDB driver : " +
e.getMessage()); } catch(SQLException e) { out.println("SQLException caught : " +
e.getMessage()); } finally { try { if (con != null) con.close();
} catch (SQLException ignored) { } } }
}
Thank you.
S.A.Pamungkas
__________________________________________________
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Kick off your party with Yahoo! Invites.
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Looking at your code, the "Couldn't load DB driver" message is being
generated by a ClassNotFound exception being thrown. This would indicate
that the org.postgresql.Driver class is not being found in the CLASSPATH.
That's probably what's going wrong here.
Peter
--
Peter Mount
Enterprise Support
Maidstone Borough Council
Any views stated are my own, and not those of Maidstone Borough Council
-----Original Message-----
From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
Sent: Monday, July 31, 2000 12:40 PM
To: pgsql-interfaces@postgresql.org
Subject: [INTERFACES] couldn't load DB driver : null
Before, I can connect database both from applet or
servlet.But today, when I try to connect database from
applet or servlet, there was a problem.
By servlet the error message is : "Couldn't load DB
driver :null".
By applet, in the browser just appear "Connecting to
database ", and in the status bar is a message "Applet
myapplet org/postgresql/jdbc2/Resultset".
Help me please......
The SERVLET code :
import java.io.*;import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class myServlet extends HttpServlet
{ public void doGet(HttpServletRequest req,
HttpServletResponse res) throws ServletException, IOException { Connection con = null;Statement stmt = null;
ResultSet rs = null; res.setContentType("text/html"); PrintWriter out = res.getWriter();
try[ Class.forName("org.postgresql.Driver"); con =
DriverManager.getConnection("jdbc:postgresql:myDB",
"me", "pass"); stmt = con.createStatement(); rs = stmt.executeQuery("select k_id,
k_name, date
from myTable");
out.println("<HTML><HEAD><TITLE>KAMOKU</TITLE></HEAD>"); out.println("<BODY><FONT
COLOR='RED'><H3><BR>TEST
SERVLET & JDBC</H3><BR></FONT>"); out.println("SELECT id, name, date FROM
kamoku<BR><BR> "); out.println("<UL>"); while(rs.next()){ out.println("<LI>" +
rs.getString("k_id")+" "+
rs.getString("k_name") + " " + rs.getDate("date")); } out.println("<UL>");
out.println("</BODY></HTML>"); } catch(ClassNotFoundException e) { out.println("Couldn't
loadDB driver : " +
e.getMessage()); } catch(SQLException e) { out.println("SQLException caught : " +
e.getMessage()); } finally { try { if (con != null) con.close();
} catch (SQLException ignored) { } } }
}
Thank you.
S.A.Pamungkas
__________________________________________________
Do You Yahoo!?
Kick off your party with Yahoo! Invites.
http://invites.yahoo.com/
Thank you.
But I already put the postgresql.jar file in the
CLASSPATH like this :
export CLASSPATH=.:/usr/local/lib/postgresql.jar
And, when I try againt ten minutes ago, applet could
connect the database ( by appletviewer ), but servlet
couldn't.
S.A.Pamungkas
--- Peter Mount <petermount@it.maidstone.gov.uk>
wrote:
> Looking at your code, the "Couldn't load DB driver"
> message is being
> generated by a ClassNotFound exception being thrown.
> This would indicate
> that the org.postgresql.Driver class is not being
> found in the CLASSPATH.
> That's probably what's going wrong here.
>
> Peter
>
> --
> Peter Mount
> Enterprise Support
> Maidstone Borough Council
> Any views stated are my own, and not those of
> Maidstone Borough Council
>
>
> -----Original Message-----
> From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
> Sent: Monday, July 31, 2000 12:40 PM
> To: pgsql-interfaces@postgresql.org
> Subject: [INTERFACES] couldn't load DB driver : null
>
>
> Before, I can connect database both from applet or
> servlet.But today, when I try to connect database
> from
> applet or servlet, there was a problem.
>
> By servlet the error message is : "Couldn't load DB
> driver :null".
> By applet, in the browser just appear "Connecting to
> database ", and in the status bar is a message
> "Applet
> myapplet org/postgresql/jdbc2/Resultset".
>
> Help me please......
>
> The SERVLET code :
> import java.io.*;import java.sql.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> public class myServlet extends HttpServlet
> {
> public void doGet(HttpServletRequest req,
> HttpServletResponse res)
> throws ServletException, IOException
> {
> Connection con = null;Statement stmt = null;
> ResultSet rs = null;
> res.setContentType("text/html");
> PrintWriter out = res.getWriter();
>
> try[
> Class.forName("org.postgresql.Driver");
> con =
> DriverManager.getConnection("jdbc:postgresql:myDB",
> "me", "pass");
> stmt = con.createStatement();
> rs = stmt.executeQuery("select k_id,
> k_name, date
> from myTable");
>
out.println("<HTML><HEAD><TITLE>KAMOKU</TITLE></HEAD>");
> out.println("<BODY><FONT
> COLOR='RED'><H3><BR>TEST
> SERVLET & JDBC</H3><BR></FONT>");
> out.println("SELECT id, name, date FROM
> kamoku<BR><BR> ");
> out.println("<UL>");
> while(rs.next()){
> out.println("<LI>" +
> rs.getString("k_id")+" "+
> rs.getString("k_name") + " " + rs.getDate("date"));
> }
> out.println("<UL>");
> out.println("</BODY></HTML>");
> }
> catch(ClassNotFoundException e)
> {
> out.println("Couldn't load DB driver : "
> +
> e.getMessage());
> }
> catch(SQLException e)
> {
> out.println("SQLException caught : " +
> e.getMessage());
> }
> finally
> {
> try
> {
> if (con != null) con.close();
> }
> catch (SQLException ignored) { }
> }
> }
> }
>
> Thank you.
>
> S.A.Pamungkas
>
> __________________________________________________
> Do You Yahoo!?
> Kick off your party with Yahoo! Invites.
> http://invites.yahoo.com/
__________________________________________________
Do You Yahoo!?
Kick off your party with Yahoo! Invites.
http://invites.yahoo.com/
I think servlets don't use CLASSPATH. An alternative is to place the jar
file into the lib/rt directory. That way, it's always available to the JVM
regardless of any classpath setting.
Peter
--
Peter Mount
Enterprise Support
Maidstone Borough Council
Any views stated are my own, and not those of Maidstone Borough Council
-----Original Message-----
From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
Sent: Monday, July 31, 2000 1:16 PM
To: pgsql-interfaces@postgresql.org
Subject: RE: [INTERFACES] couldn't load DB driver : null
Thank you.
But I already put the postgresql.jar file in the
CLASSPATH like this :
export CLASSPATH=.:/usr/local/lib/postgresql.jar
And, when I try againt ten minutes ago, applet could
connect the database ( by appletviewer ), but servlet
couldn't.
S.A.Pamungkas
--- Peter Mount <petermount@it.maidstone.gov.uk>
wrote:
> Looking at your code, the "Couldn't load DB driver"
> message is being
> generated by a ClassNotFound exception being thrown.
> This would indicate
> that the org.postgresql.Driver class is not being
> found in the CLASSPATH.
> That's probably what's going wrong here.
>
> Peter
>
> --
> Peter Mount
> Enterprise Support
> Maidstone Borough Council
> Any views stated are my own, and not those of
> Maidstone Borough Council
>
>
> -----Original Message-----
> From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
> Sent: Monday, July 31, 2000 12:40 PM
> To: pgsql-interfaces@postgresql.org
> Subject: [INTERFACES] couldn't load DB driver : null
>
>
> Before, I can connect database both from applet or
> servlet.But today, when I try to connect database
> from
> applet or servlet, there was a problem.
>
> By servlet the error message is : "Couldn't load DB
> driver :null".
> By applet, in the browser just appear "Connecting to
> database ", and in the status bar is a message
> "Applet
> myapplet org/postgresql/jdbc2/Resultset".
>
> Help me please......
>
> The SERVLET code :
> import java.io.*;import java.sql.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> public class myServlet extends HttpServlet
> {
> public void doGet(HttpServletRequest req,
> HttpServletResponse res)
> throws ServletException, IOException
> {
> Connection con = null;Statement stmt = null;
> ResultSet rs = null;
> res.setContentType("text/html");
> PrintWriter out = res.getWriter();
>
> try[
> Class.forName("org.postgresql.Driver");
> con =
> DriverManager.getConnection("jdbc:postgresql:myDB",
> "me", "pass");
> stmt = con.createStatement();
> rs = stmt.executeQuery("select k_id,
> k_name, date
> from myTable");
>
out.println("<HTML><HEAD><TITLE>KAMOKU</TITLE></HEAD>");
> out.println("<BODY><FONT
> COLOR='RED'><H3><BR>TEST
> SERVLET & JDBC</H3><BR></FONT>");
> out.println("SELECT id, name, date FROM
> kamoku<BR><BR> ");
> out.println("<UL>");
> while(rs.next()){
> out.println("<LI>" +
> rs.getString("k_id")+" "+
> rs.getString("k_name") + " " + rs.getDate("date"));
> }
> out.println("<UL>");
> out.println("</BODY></HTML>");
> }
> catch(ClassNotFoundException e)
> {
> out.println("Couldn't load DB driver : "
> +
> e.getMessage());
> }
> catch(SQLException e)
> {
> out.println("SQLException caught : " +
> e.getMessage());
> }
> finally
> {
> try
> {
> if (con != null) con.close();
> }
> catch (SQLException ignored) { }
> }
> }
> }
>
> Thank you.
>
> S.A.Pamungkas
>
> __________________________________________________
> Do You Yahoo!?
> Kick off your party with Yahoo! Invites.
> http://invites.yahoo.com/
__________________________________________________
Do You Yahoo!?
Kick off your party with Yahoo! Invites.
http://invites.yahoo.com/
This is correct; in JServ there's a jserv.properties file with the classpath settings, in Tomcat, you can put the
postgresql.jarfile under ./webapps/<app_name>/WEB-INF/lib to have it included automatically.
Cheers,
Joe
>-----Original Message-----
>From: pgsql-interfaces-owner@hub.org
>[mailto:pgsql-interfaces-owner@hub.org]On Behalf Of Peter Mount
>Sent: Monday, 31 July 2000 10:22 PM
>To: 'S.A.Pamungkas'; pgsql-interfaces@postgresql.org
>Subject: RE: [INTERFACES] couldn't load DB driver : null
>
>
>I think servlets don't use CLASSPATH. An alternative is to place the jar
>file into the lib/rt directory. That way, it's always available to the JVM
>regardless of any classpath setting.
>
>Peter
>
>--
>Peter Mount
>Enterprise Support
>Maidstone Borough Council
>Any views stated are my own, and not those of Maidstone Borough Council
>
>
>-----Original Message-----
>From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
>Sent: Monday, July 31, 2000 1:16 PM
>To: pgsql-interfaces@postgresql.org
>Subject: RE: [INTERFACES] couldn't load DB driver : null
>
>
>Thank you.
>But I already put the postgresql.jar file in the
>CLASSPATH like this :
>export CLASSPATH=.:/usr/local/lib/postgresql.jar
>
>And, when I try againt ten minutes ago, applet could
>connect the database ( by appletviewer ), but servlet
>couldn't.
>
>S.A.Pamungkas
>
>--- Peter Mount <petermount@it.maidstone.gov.uk>
>wrote:
>> Looking at your code, the "Couldn't load DB driver"
>> message is being
>> generated by a ClassNotFound exception being thrown.
>> This would indicate
>> that the org.postgresql.Driver class is not being
>> found in the CLASSPATH.
>> That's probably what's going wrong here.
>>
>> Peter
>>
>> --
>> Peter Mount
>> Enterprise Support
>> Maidstone Borough Council
>> Any views stated are my own, and not those of
>> Maidstone Borough Council
>>
>>
>> -----Original Message-----
>> From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
>> Sent: Monday, July 31, 2000 12:40 PM
>> To: pgsql-interfaces@postgresql.org
>> Subject: [INTERFACES] couldn't load DB driver : null
>>
>>
>> Before, I can connect database both from applet or
>> servlet.But today, when I try to connect database
>> from
>> applet or servlet, there was a problem.
>>
>> By servlet the error message is : "Couldn't load DB
>> driver :null".
>> By applet, in the browser just appear "Connecting to
>> database ", and in the status bar is a message
>> "Applet
>> myapplet org/postgresql/jdbc2/Resultset".
>>
>> Help me please......
>>
>> The SERVLET code :
>> import java.io.*;import java.sql.*;
>> import javax.servlet.*;
>> import javax.servlet.http.*;
>>
>> public class myServlet extends HttpServlet
>> {
>> public void doGet(HttpServletRequest req,
>> HttpServletResponse res)
>> throws ServletException, IOException
>> {
>> Connection con = null;Statement stmt = null;
>> ResultSet rs = null;
>> res.setContentType("text/html");
>> PrintWriter out = res.getWriter();
>>
>> try[
>> Class.forName("org.postgresql.Driver");
>> con =
>> DriverManager.getConnection("jdbc:postgresql:myDB",
>> "me", "pass");
>> stmt = con.createStatement();
>> rs = stmt.executeQuery("select k_id,
>> k_name, date
>> from myTable");
>>
>out.println("<HTML><HEAD><TITLE>KAMOKU</TITLE></HEAD>");
>> out.println("<BODY><FONT
>> COLOR='RED'><H3><BR>TEST
>> SERVLET & JDBC</H3><BR></FONT>");
>> out.println("SELECT id, name, date FROM
>> kamoku<BR><BR> ");
>> out.println("<UL>");
>> while(rs.next()){
>> out.println("<LI>" +
>> rs.getString("k_id")+" "+
>> rs.getString("k_name") + " " + rs.getDate("date"));
>> }
>> out.println("<UL>");
>> out.println("</BODY></HTML>");
>> }
>> catch(ClassNotFoundException e)
>> {
>> out.println("Couldn't load DB driver : "
>> +
>> e.getMessage());
>> }
>> catch(SQLException e)
>> {
>> out.println("SQLException caught : " +
>> e.getMessage());
>> }
>> finally
>> {
>> try
>> {
>> if (con != null) con.close();
>> }
>> catch (SQLException ignored) { }
>> }
>> }
>> }
>>
>> Thank you.
>>
>> S.A.Pamungkas
>>
>> __________________________________________________
>> Do You Yahoo!?
>> Kick off your party with Yahoo! Invites.
>> http://invites.yahoo.com/
>
>
>__________________________________________________
>Do You Yahoo!?
>Kick off your party with Yahoo! Invites.
>http://invites.yahoo.com/
>
Thank you for all persons help me.
I'm using jdk1.2, and my problem was solved by putting
postgresql.jar in the directory
/usr/local/jdk12/jre/lib/ext/
I don't know why...... but the important one is now
servlet working good.
-pamungkas-
--- Joe Shevland <shevlandj@kpi.com.au> wrote:
> This is correct; in JServ there's a jserv.properties
> file with the classpath settings, in Tomcat, you can
> put the postgresql.jar file under
> ./webapps/<app_name>/WEB-INF/lib to have it included
> automatically.
>
> Cheers,
> Joe
>
> >-----Original Message-----
> >From: pgsql-interfaces-owner@hub.org
> >[mailto:pgsql-interfaces-owner@hub.org]On Behalf Of
> Peter Mount
> >Sent: Monday, 31 July 2000 10:22 PM
> >To: 'S.A.Pamungkas';
> pgsql-interfaces@postgresql.org
> >Subject: RE: [INTERFACES] couldn't load DB driver :
> null
> >
> >
> >I think servlets don't use CLASSPATH. An
> alternative is to place the jar
> >file into the lib/rt directory. That way, it's
> always available to the JVM
> >regardless of any classpath setting.
> >
> >Peter
> >
> >--
> >Peter Mount
> >Enterprise Support
> >Maidstone Borough Council
> >Any views stated are my own, and not those of
> Maidstone Borough Council
> >
> >
> >-----Original Message-----
> >From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
> >Sent: Monday, July 31, 2000 1:16 PM
> >To: pgsql-interfaces@postgresql.org
> >Subject: RE: [INTERFACES] couldn't load DB driver :
> null
> >
> >
> >Thank you.
> >But I already put the postgresql.jar file in the
> >CLASSPATH like this :
> >export CLASSPATH=.:/usr/local/lib/postgresql.jar
> >
> >And, when I try againt ten minutes ago, applet
> could
> >connect the database ( by appletviewer ), but
> servlet
> >couldn't.
> >
> >S.A.Pamungkas
> >
> >--- Peter Mount <petermount@it.maidstone.gov.uk>
> >wrote:
> >> Looking at your code, the "Couldn't load DB
> driver"
> >> message is being
> >> generated by a ClassNotFound exception being
> thrown.
> >> This would indicate
> >> that the org.postgresql.Driver class is not being
> >> found in the CLASSPATH.
> >> That's probably what's going wrong here.
> >>
> >> Peter
> >>
> >> --
> >> Peter Mount
> >> Enterprise Support
> >> Maidstone Borough Council
> >> Any views stated are my own, and not those of
> >> Maidstone Borough Council
> >>
> >>
> >> -----Original Message-----
> >> From: S.A.Pamungkas [mailto:moenk_2000@yahoo.com]
> >> Sent: Monday, July 31, 2000 12:40 PM
> >> To: pgsql-interfaces@postgresql.org
> >> Subject: [INTERFACES] couldn't load DB driver :
> null
> >>
> >>
> >> Before, I can connect database both from applet
> or
> >> servlet.But today, when I try to connect database
> >> from
> >> applet or servlet, there was a problem.
> >>
> >> By servlet the error message is : "Couldn't load
> DB
> >> driver :null".
> >> By applet, in the browser just appear "Connecting
> to
> >> database ", and in the status bar is a message
> >> "Applet
> >> myapplet org/postgresql/jdbc2/Resultset".
> >>
> >> Help me please......
> >>
> >> The SERVLET code :
> >> import java.io.*;import java.sql.*;
> >> import javax.servlet.*;
> >> import javax.servlet.http.*;
> >>
> >> public class myServlet extends HttpServlet
> >> {
> >> public void doGet(HttpServletRequest req,
> >> HttpServletResponse res)
> >> throws ServletException, IOException
> >> {
> >> Connection con = null;Statement stmt =
> null;
> >> ResultSet rs = null;
> >> res.setContentType("text/html");
> >> PrintWriter out = res.getWriter();
> >>
> >> try[
> >>
> Class.forName("org.postgresql.Driver");
> >> con =
> >>
> DriverManager.getConnection("jdbc:postgresql:myDB",
> >> "me", "pass");
> >> stmt = con.createStatement();
> >> rs = stmt.executeQuery("select k_id,
> >> k_name, date
> >> from myTable");
> >>
>
>out.println("<HTML><HEAD><TITLE>KAMOKU</TITLE></HEAD>");
> >> out.println("<BODY><FONT
> >> COLOR='RED'><H3><BR>TEST
> >> SERVLET & JDBC</H3><BR></FONT>");
> >> out.println("SELECT id, name, date
> FROM
> >> kamoku<BR><BR> ");
> >> out.println("<UL>");
> >> while(rs.next()){
> >> out.println("<LI>" +
> >> rs.getString("k_id")+" "+
> >> rs.getString("k_name") + " " +
> rs.getDate("date"));
> >> }
> >> out.println("<UL>");
> >> out.println("</BODY></HTML>");
> >> }
> >> catch(ClassNotFoundException e)
> >> {
> >> out.println("Couldn't load DB driver
> : "
> >> +
> >> e.getMessage());
> >> }
> >> catch(SQLException e)
> >> {
> >> out.println("SQLException caught : "
> +
> >> e.getMessage());
> >> }
> >> finally
> >> {
> >> try
> >> {
> >> if (con != null) con.close();
> >> }
> >> catch (SQLException ignored) { }
> >> }
> >> }
> >> }
> >>
> >> Thank you.
> >>
> >> S.A.Pamungkas
> >>
> >>
> __________________________________________________
> >> Do You Yahoo!?
> >> Kick off your party with Yahoo! Invites.
> >> http://invites.yahoo.com/
> >
> >
> >__________________________________________________
> >Do You Yahoo!?
> >Kick off your party with Yahoo! Invites.
> >http://invites.yahoo.com/
> >
>
__________________________________________________
Do You Yahoo!?
Kick off your party with Yahoo! Invites.
http://invites.yahoo.com/