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driver problem

 
Greenhorn
Posts: 8
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hi,

i am using one servlet program (simple java program) in which,i am calling another java program which is simple connection to mysql database.

i am new to this and please be patient to my problem..thanks in advance...

i am unable to connect to the database..the reason for it i could not understand.i set classpaths and everthing correctly.

my code is as below:
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;


public class HelloServlet extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String docType =
"<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 " +
"Transitional//EN\">\n";
out.println(docType +
"<HTML>\n" +
"<HEAD><TITLE>Java Servlet done by L p Mahesh</TITLE></HEAD>\n" +
"<BODY BGCOLOR=\"#FDF5E6\">\n" +
"<H1>Hello,My name is lanka poojya mahesh</H1>\n" +
"</BODY></HTML>");

Exp ex = new Exp();

out.println("1");
ex.print();
out.println("2");

}//end of doGet method
}//end of helloservlet

and Exp.java program is below:

import java.io.*;
import java.sql.*;
import java.sql.*;
import java.util.*;


public class Exp
{
public Exp()
{
System.out.println("test");
Connection conn = null;

try
{
System.out.println("001");

String userName = "root";
String password = "admin";

System.out.println("012");

String url = "jdbc:mysql://localhost:3306/mysql";

System.out.println("123");

Class.forName ("org.gjt.mm.mysql.Driver");

System.out.println("234");

conn = DriverManager.getConnection (url, userName, password);
System.out.println ("Database connection established");
}
catch (Exception e)
{
System.err.println ("Cannot connect to database server");
}
finally
{
if (conn != null)
{
try
{
conn.close ();
System.out.println ("Database connection terminated");
}
catch (Exception e) { /* ignore close errors */ }
}
}//end of finally


} // nd of Exp()
public int print()
{
System.out.println("inside this");
return 2;
}
}

upto this line "System.out.println("123");"
prog is ruunig correctly ..after that it is coming out pf try loop and stmt in catch is executed.

please solve my doubt......i would really apreciate that..thanks in advance...
 
author & internet detective
Posts: 41937
911
Eclipse IDE VI Editor Java
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First thing is to confirm the error by putting e.printStackTrace() in the catch block.

From the position, it is likely that you are experiencing a classpath problem. What server are you using? Tomcat, JBoss, WebSphere, WebLogic, etc.
 
mahesh lanka
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hi,

thank you very much for the reply...i am new to java and servlets...please help me....as you said ,I did ,and the following exception came:

i am using apache tomcat server.



java.lang.ClassNotFoundException: org.gjt.mm.mysql.Driver
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoa
der.java:1340)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoa
der.java:1189)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at Exp.<init>(Exp.java:27)
at HelloServlet.doGet(HelloServlet.java:22)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(Standard
ContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:117)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)

at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:16
0)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java
:793)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proce
ssConnection(Http11Protocol.java:702)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java
:571)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadP
ool.java:644)
at java.lang.Thread.run(Thread.java:595)

Cannot connect to database server

Please help me.....I set the classpath of mysql driver before running of the program..but still I could not able to connect...

regards,
mahesh
 
Ranch Hand
Posts: 518
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Note that the exception is:

java.lang.ClassNotFoundException: org.gjt.mm.mysql.Driver



The JVM can't find the class org.gjt.mm.mysql.Driver. Be sure that the jar containing this class is in your app's WEB-INF/lib directory or the tomcat common/lib directory.
[ October 19, 2006: Message edited by: Scott Johnson ]
 
mahesh lanka
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Posts: 8
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hi scott,

thanks man..it worked..and you solved my problem..thanks once again...thanks to all who helped me.....

regards,
mahesh
 
Scott Johnson
Ranch Hand
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You are most welcome!
 
Maybe he went home and went to bed. And took this tiny ad with him:
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