輸入用戶名密碼，點擊登陸按鈕后報錯：

代碼如下：

dologin.jsp

<%@?page?contentType="text/html;charset=UTF-8"?language="java"?import?=?"java.util.*"%>

<%
????request.setCharacterEncoding("utf-8");
%>

????<jsp:useBean?id="userVerify"?class?=?"UsersVerify"?scope="application"?/>
????<jsp:useBean?id?=?"loginUser"?class?=?"Users"?scope?=?"application"/>
????<jsp:setProperty?name="loginUser"?property="*"?/>

????<%
????????if?(userVerify.isValid(loginUser))?{
????????????//?成功則轉發
????????????session.setAttribute("username",?loginUser.getUsername());
????????????request.getRequestDispatcher("success.jsp").forward(request,?response);
????????}?else?{
????????????//?登陸失敗則重定向
????????????response.sendRedirect("failure.jsp");
????????}
????%>

Users.java

public?class?Users?{
????private?String?username;
????private?String?password;

????public?Users(){}

????public?void?setUsername(String?username)?{
????????this.username?=?username;
????}

????public?void?setPassword(String?password)?{
????????this.password?=?password;
????}

????public?String?getUsername()?{
????????return?username;
????}

????public?String?getPassword()?{
????????return?password;
????}
}

UsersVerify.java

public?class?UsersVerify?{
????//?private?boolean?isValid?=?false;

????public?UsersVerify()?{}

????public?boolean?isValid(Users?u)?{
????????if?(u.getUsername().equals("admin")?&&?u.getPassword().equals("123456"))?{
????????????return?true;
????????}
????????return?false;
????}
}