Question

Project使用MySql在Java Spring MVC上。显示无法正常工作（下面附带的图片），因为函数可能没有返回查询结果，也可能是其他原因。以下是用于在数据库上运行查询并返回结果的函数。该函数是＆＃34; User.java＆＃34;的成员。文件。

public List<User> getUsers()
{  
    return jdbcTemplate.query("select * from student",new RowMapper<User>()
            {  
                public User mapRow(ResultSet rs, int row) throws SQLException 
                {  
                    User u = new User();  
                    u.setUserName(rs.getString(1));  
                    u.setPassword(rs.getString(2));  
                    u.setName(rs.getString(3));  
                    u.setBranch(rs.getString(4));
                    u.setM1(rs.getInt(5));
                    u.setM2(rs.getInt(6));
                    u.setM3(rs.getInt(7));
                    u.setAggregate(rs.getInt(8));
                    u.setGrade(rs.getString(9));
                    return u;  
                }  
            });  
}

返回＆＃34; HomeController.java＆＃34;它的实现如下..

@RequestMapping("/adminHome")  
public ModelAndView adminHome(User user){  
    List<User> list= user.getUsers();  
    return new ModelAndView("adminHome","list",list);  
}

，相应的JSP是＆＃34; adminHome.jsp＆＃34;，如下所示......

<body>
<h3>Hi ${name}</h3>
<h1>USERS List</h1>  
<table border="2" width="70%" cellpadding="2">  
<tr><th>Username</th><th>Password</th><th>Name</th><th>Mobile</th>
<th>Branch</th><th>Marks1</th><th>Marks2</th><th>Marks3</th>
<th>Aggregate</th><th>Grade</th><th>Edit</th>
<th>Delete</th></tr>  
   <c:forEach var="u" items="${list}">   
   <tr>  
   <td>${u.username}</td>
   <td>${u.password}</td>   
   <td>${u.name}</td>  
   <td>${u.mobile}</td>  
   <td>${u.branch}</td>
   <td>${u.marks1}</td>
   <td>${u.marks2}</td>
   <td>${u.marks3}</td>
   <td>${u.aggregate}</td>
   <td>${u.grade}</td>   
   <td><a href="editemp/${u.username}">Edit</a></td>  
   <td><a href="deleteemp/${u.username}">Delete</a></td>  
   </tr>  
   </c:forEach>  
   </table>  
   <br/>  
   <a href="register">Add New User</a>     
</body>

This is the final output and the list of users is not returning

@RequestMapping(value = "/user", method = RequestMethod.POST)
public String user(@Validated User user, Model model,Locale locale) 
{
    U = user.getUserName();
    String s1 = "password";
    String s2 = "name";
    String p = "X";
    try
    {
        final String selectQuery = "select * from student where username='"+U+"'";  
        Map<?, ?> map = jdbcTemplate.queryForMap(selectQuery);
        Set set  = map.entrySet();
        Iterator itr=set.iterator();  

        while(itr.hasNext())
        {  
            //Converting to Map.Entry so that we can get key and value separately  
            Map.Entry entry=(Map.Entry)itr.next();  
            if(entry.getKey().equals(s1))
            {   
                p = entry.getValue().toString();
                System.out.println(p);
            }
            if(entry.getKey().equals(s2))
            {   
                NAME = entry.getValue().toString();
                System.out.println(p);
            }          
        }  
    }
    catch(Exception e2)
    {
        System.out.println("Exception Raised while Login(user)!!!");            //not inclusion of case of NULL return by username search in the sql query
    }

    String dest="user";
    if(user.getUserName().equals("admin") && user.getPassword().equals(p))
    {
        dest = "adminHome";
        System.out.println("Admin Page Requested");
        model.addAttribute("name", NAME);
    }
    else if(user.getUserName().equals(U) && user.getPassword().equals(p))
    {
        System.out.println("User Page Requested");
        model.addAttribute("name", NAME);
    }
    else
    {
        dest = "errLogin";                                                          //redirects to errLogin.jsp
        System.out.println("Err Login Page Requested, locale = " + locale);
        Date date = new Date();
        DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);
        String formattedDate = dateFormat.format(date);

        model.addAttribute("serverTime", formattedDate);
        model.addAttribute("message", "Invalid login credentials !!! Try Again");                   
    }   
    return dest;
}

Answer 1

您没有将其正确地重定向到/adminHome服务。相反，它会重定向到adminHome.jsp页面。

如果您想将其从/adminHome服务重定向到/user，而不是return "adminHome";，请执行以下操作 -

@RequestMapping(value = "/user", method = RequestMethod.POST)
public String user(@Validated User user, Model model,Locale locale) {
    // your code and use return line as follows
    return "redirect:adminHome";
}

当您使用String dest作为最终回复语句时，请将其更新为"redirect:<service_name>"。

这应该调用您的/adminHome服务，一切都应该正常。

数据库详细信息未在Spring-MVC中显示

1 个答案: