Salve,

sto realizzando una semplice Web Application che si colleghi a MySQL tramite JDBC ma sto riscontrando problemi.
Non sto usando al momento un IDE per meglio capire tutti i passaggi.
Io penso che il problema sia il connector-j... ma andiamo con ordine:

Di seguito la disposizione dei file:
.
├── index.html
├── pages
│__ ├── Error.jsp
│__ ├── NotFound.jsp
│__ └── Welcome.jsp
└── WEB-INF
├── classes
│__ └── Login.class
├── lib
│__ └── mysql-connector-java-5.1.18-bin.jar
├── src
│__ └── Login.java
└── web.xml

Codice del file index.html:
Codice PHP:
[...]
<
form action="Welcome">
     
username: <input name="user" type="text">

     
password: <input name="pwd" type="text">

     <
input name="submit" type="submit"
</
form>
[...] 
Il codice della Servlet Login.java:
Codice PHP:
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;

public class 
Login extends HttpServlet
        public 
void doGet(HttpServletRequest requestHttpServletResponse response)    
            
throws IOExceptionServletException{
            
            
String userpwd;
            
String output;
            
int userCount 0;

            
user request.getParameter("user");
            
pwd request.getParameter("pwd");

            try{
                
// connessione al db mysql
                
Class.forName("com.mysql.jdbc.Driver");
                
Connection conn DriverManager.getConnection("jdbc:mysql://localhost:3306/sampleDb""*****""*****");

                
// eseguo la query
                
Statement stmt conn.createStatement();
                
String query "select count(id) as num from users where username='"
                        
+user +"' and password='" +pwd +"'";

                
ResultSet result stmt.executeQuery(query);
                while(
result.next()){
                    
int columnCount result.getMetaData().getColumnCount();
                    for(
int i 1<= columnCounti++){
                        
userCount result.getInt(i);
                    }
                }

                
// chiudo la connessione
                
conn.close(); 

            }catch(
Exception e){
                
output "pages/Error.jsp";
            }

            if(
userCount 0){
                
output "pages/Welcome.jsp";
            }else{
                
output "pages/NotFound.jsp";
            }

            
// reindirizzo il browser verso la pagina corretta
            
request.getRequestDispatcher(output).forward(requestresponse);
        }

Il file web.xml:
Codice PHP:
<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app 
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" 
    "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>

        <display-name> LiginSample </display-name>

        
        <context-param>
                <param-name> driverClassName  </param-name>
                <param-value> com.mysql.jdbc.Driver </param-value>
        </context-param>        
        <context-param>
                <param-name> url </param-name>
                <param-value> JDBC:MySQL://localhost:3306/sampleDb </param-value>
        </context-param>
        <context-param>
                <param-name> username </param-name>
                <param-value> ***** </param-value>
        </context-param>
        <context-param>
                <param-name> password </param-name>
                <param-value> ***** </param-value>
        </context-param>

        
        <servlet>
                <servlet-name> Login </servlet-name>
                <selvlet-class> Login </servlet-class>
        </servlet>

        <servlet-mapping>
                <servlet-name> Login </servlet-name>
                <url-pattern> /Welcome </url-pattern>
        </servlet-mapping>
        
</web-app>
Ho anche inserito il file mysql-connector-java-5.1.18-bin.jar in /opt/tomcat/lib
ma nulla

Qualche suggerimento?

Grazie dell'attenzione,
Matteo