在java语言中有2个单选按钮的登录页面

Question

我有一个登录页面，当我运行它时，它必须检查哪个单选按钮被检查并检查该单选按钮的数据库。 当我运行代码我得到这个错误：

HTTP Status 500 - Request processing failed; 
    nested exception is java.lang.NullPointerException 

和 这是我的网页：

<form action="/HelloWorldInWeb/login" method="post"> 
      <div class="col-lg-12" id="div3"> 
       <div class="form-group input-group" id="div4"> 
       <div class="input-group-addon "><span class="glyphicon glyphicon-eye-open "></span></div> 
        <input type="text" class="form-control" name="username" id="textbox1" placeholder="Enter your username"> 
       </div> 
       <div class="form-group input-group" id="div5"> 
       <div class="input-group-addon "><span class="glyphicon glyphicon-eye-close "></span></div> 
        <input type="text" class="form-control" name="password" id="textbox2" placeholder="Enter your Password"> 
       </div> 
       <div class="form-group" id="div6"> 
        <label><input type="radio" name="sign" name="checkbox" value="adminstrator" id="adminstrator" checked>Adminstrator</label> 
        <label><input type="radio" name="sign" name="checkbox" value="admin" id="admin">Admin</label> 
       </div> 
       <div class="align"> 
       <button type="submit" class="btn btn-danger">Ok</button> 
       </div> 
      </div> 
    </form> 

这是我CONTROLER的servelt：

@SuppressWarnings({ "null", "static-access"}) 
     @RequestMapping(value="/login" , method = RequestMethod.POST) 
     protected void doPost(HttpServletRequest reque, HttpServletResponse response) throws ServletException, IOException { 

      response.setContentType("text/html"); 
      PrintWriter out = response.getWriter(); 

      String username=reque.getParameter("username"); 
      String password=reque.getParameter("password"); 
      String radio=reque.getParameter("checkbox"); 



     if(radio.equals("admin")){ 
      Boolean t = stdDAO.validate(username, password); 
      if(t){ 
        out.print(username); 
        out.print(password); 
        out.print(" username or password succes"); 

        response.sendRedirect("/HelloWorldInWeb/addozvv"); 

       } 
       else{ 
        out.print(username); 
        out.print(password); 
        out.print("Sorry username or password error"); 
        response.sendRedirect("/HelloWorldInWeb/login"); 
       } 

       out.close(); 
     }else 
      if(radio.equals("adminstrator")){ 
       Boolean s = stdDAO.validateadm(username, password); 
       if(s){ 
         out.print(username); 
         out.print(password); 
         out.print(" username or password succes"); 

         response.sendRedirect("/HelloWorldInWeb/addozvv"); 

        } 
        else{ 
         out.print(username); 
         out.print(password); 
         out.print("Sorry username or password error"); 
         response.sendRedirect("/HelloWorldInWeb/login"); 
        } 
      } 




      } 

这是我的验证：

public Boolean validate(String username, String password) { 
     boolean t =false; 
     try{ 
      Connection con = dataSource.getConnection(); 
      PreparedStatement ps =con.prepareStatement 
           ("select * from admins where username=? and password=?"); 
      ps.setString(1, username); 
      ps.setString(2, password); 
      ResultSet rs =ps.executeQuery(); 
      t = rs.next(); 

     }catch(Exception e) 
     { 
      e.printStackTrace(); 
     } 
     return t; 
    } 

    @Override 
    public java.lang.Boolean validateadm(String username, String password) { 
     boolean s =false; 
     try{ 
      Connection con = dataSource.getConnection(); 
      PreparedStatement ps =con.prepareStatement 
           ("select * from admin where username=? and password=?"); 
      ps.setString(1, username); 
      ps.setString(2, password); 
      ResultSet rs =ps.executeQuery(); 
      s = rs.next(); 

     }catch(Exception e) 
     { 
      e.printStackTrace(); 
     } 
     return s; 

    } 

Answer 1

radio可能为空。在if陈述中使用"admin". equals(radio)和"administrator".equals(radio)。