请高手看一下这个  java 文件那里出错了，为什么编译不了javaBean？
急~~~~   [em17]


package classmate;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.*;


public class LoginAction extends HttpServlet
{

    public LoginAction()
    {
    }

    public void init(ServletConfig servletconfig)
        throws ServletException
    {
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
        request.setCharacterEncoding("UTF-8");
        String uname = request.getParameter("uname");
        String psw = request.getParameter("psw");
        response.setContentType("text/xml; charset=UTF-8");
        response.setHeader("Cache-Control", "no-cache");
        PrintWriter out = response.getWriter();
        out.println("<response>");
        DB db = new DB();
        String strSql = null;
        strSql = "select * from classuser where username='" + uname + "' and password='" + psw + "'";
        ResultSet rs = db.executeQuery(strSql);
        try
        {
            if (rs.next())
                out.println("<res>热烈的欢迎您!</res>");
            else
                out.println("<res>对不起,登录失败！</res>");
        }
        catch (SQLException e)
        {
            e.printStackTrace();
        }
        out.println("</response>");
        out.close();
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
        doGet(request, response);
    }
}