Ciao, sto cercando di realizzare una piccola pagina di login in jsp. Tuttavia mi da il seguente errore:
org.apache.jasper.JasperException: An exception occurred processing JSP page /logpage.jsp at line 40

37: {
38: String username=resultset.getString(1);
39: String password=resultset.getString(2);
40: if(user.equals(username) && pass.equals(password))
41: {%>
42: <jsp:forward page="success.html" />
43: <%}


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handle JspException(JspServletWrapper.java:567)
org.apache.jasper.servlet.JspServletWrapper.servic e(JspServletWrapper.java:471)
org.apache.jasper.servlet.JspServlet.serviceJspFil e(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspSe rvlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet .java:722)
root cause

java.lang.NullPointerException
org.apache.jsp.logpage_jsp._jspService(logpage_jsp .java:104)
org.apache.jasper.runtime.HttpJspBase.service(Http JspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet .java:722)
org.apache.jasper.servlet.JspServletWrapper.servic e(JspServletWrapper.java:433)
org.apache.jasper.servlet.JspServlet.serviceJspFil e(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspSe rvlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet .java:722)

la pagina la posto qui di seguito:
codice:
 
<%@ page language ="java" import="java.sql.*" %>
<%! String DRIVER = "com.mysql.jdbc.Driver";
String DB_URL = "jdbc:mysql://localhost:3306/wine";
%>
<html>
<head>
</head>
<body bgcolor="pink">
	<form name="f1" action="login.jsp" method="post">
	<table>
	<tr>
		<td>User Name</td><td><input type="text" name="user" ></td>
		</tr>
		<td>Password</td>
		<td><input type="password" name="passw"></td>
	</tr>
	<tr>
	<td></td>
	<td><input type="submit" name="b1" value="LogIn"></td>
	</tr>
	</table>
<%
String user=request.getParameter("user");
String pass=request.getParameter("passw");

// Carico il driver.
Class.forName(DRIVER).newInstance();
Connection connection = null;
try { 
	// Apro la connesione verso il database.
    connection =DriverManager.getConnection(DB_URL,"root","dbpass");
	// Ottengo lo Statement per interagire con il database.
	Statement statement = connection.createStatement();
    // Interrogo il DBMS mediante una query SQL.
	ResultSet resultset = statement.executeQuery("SELECT Email, Password FROM Utente");
    while(resultset.next())
    {
        String username=resultset.getString(1);
        String password=resultset.getString(2);
        if(user.equals(username) && pass.equals(password))
        {%>
            <jsp:forward page="success.html" />
      <%}
        else out.println("Login Failed,Please try Again");
      %><%
    }
}
catch (SQLException e) 
{
// In caso di errore...
%>Eccezione: <%= e.toString() %><%
} 
finally
{
	if (connection != null) connection.close();
}
%>
	</form>
</body>
</html>