关于简单JavaWeb应用的问题

我目前的状态：
1.创建好了目录结构。
2.已写好login.htm
<html>
<head>
<title>helloapp</title>
</head>
<body>
<form name="loginForm" method="POST" action="dispatcher">
<table>
<tr>
<td><div align="right">User Name:</div></td>
<td><input type = "text" name="username"></td>
</tr>

<tr>
<td><div align="right">Password:</div></td>
<td><input type = "password" name="password"></td>
</tr>

<tr>
<td><input type="submit" name="submit" value="submit"></td>
<td><input type="reset" name="reset" value="reset"></td>
</tr>

</table>
</form>
</body>
</html>
3.已写好hello.jsp
<html>
<head><title>helloapp</title></head>
<body>
<b>Hello:<%=request.getAttribute("USER")%></b>
</body>
</html>
4.已写好DispatcherServlet.class
package mypack;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;


public class DispatcherServlet extends GenericServlet{

private String target = "/hello.jsp";

public void service(ServletRequest request, ServletResponse response)
throws ServletException, IOException{
String username = request.getParameter("username");
String password = request.getParameter("password");

request.setAttribute("USER",username);
request.setAttribute("PASSWORD",password);

ServletContext context = getServletContext();
RequestDispatcher dispatcher = context.getRequestDispatcher(target);
dispatcher.forward(request, response);
}
}我目前的状态：
1.创建好了目录结构。
2.已写好login.htm
<html>
<head>
<title>helloapp</title>
</head>
<body>
<form name="loginForm" method="POST" action="dispatcher">
<table>
<tr>
<td><div align="right">User Name:</div></td>
<td><input type = "text" name="username"></td>
</tr>

<tr>
<td><div align="right">Password:</div></td>
<td><input type = "password" name="password"></td>
</tr>

<tr>
<td><input type="submit" name="submit" value="submit"></td>
<td><input type="reset" name="reset" value="reset"></td>
</tr>

</table>
</form>
</body>
</html>
3.已写好hello.jsp
<html>
<head><title>helloapp</title></head>
<body>
<b>Hello:<%=request.getAttribute("USER")%></b>
</body>
</html>
4.已写好DispatcherServlet.class
package mypack;

import javax.servlet.*;
import javax.servlet.http.*; dnfbaibao.com
import java.io.*;
import java.util.*;


public class DispatcherServlet extends GenericServlet{

private String target = "/hello.jsp";

public void service(ServletRequest request, ServletResponse response)
throws ServletException, IOException{
String username = request.getParameter("username");
String password = request.getParameter("password");

request.setAttribute("USER",username);
request.setAttribute("PASSWORD",password);

ServletContext context = getServletContext();
RequestDispatcher dispatcher = context.getRequestDispatcher(target);
dispatcher.forward(request, response);
}
}