Spring-如何比较JSP表单中的值和db中的值？ （服务+ DAO）

Question

I'm making a web application (Virtual Clinic)I made DAO and Service layers (I'm beginner at it) for that and it works fine in Controller, but I don't know how can I compare @ModelAttribute("user") User user to values (login, password) which are in db, I want in order to application will redirect to Home.jsp if entered values are in database, if not - then app will redirect to different jsp. Could somebody show me how should I do it properly?

Here is a code:

LoginController:

@RequestMapping(value="/home.html", method = RequestMethod.POST)
public ModelAndView homePagePost(@ModelAttribute("user") User user)
{   
    setAppContext();         
    clinicService.checkAuthentication(user);     

    ModelAndView home = new ModelAndView("Home");
    return home;
}

Login.jsp:

<form action="/VirtualClinic/home.html" method="post">
  <input type="text" name="login" placeholder="Login"/>
  <input type="password" name="password" placeholder="Password"/>
  <button>Login</button>
</form>

UserDaoImpl:

public void checkAuthentication(User user) {
    String query = "SELECT login, password FROM virtualclinic.user WHERE login=? AND password=?";
    Connection con = null;
    PreparedStatement ps = null;
    try{
        con = dataSource.getConnection();
        ps = con.prepareStatement(query);
        ps.setString(1, user.getLogin());
        ps.setString(2, user.getPassword());
        ResultSet out = ps.executeQuery();

    }catch(SQLException e){
        e.printStackTrace();
    }finally{
        try {
            ps.close();
            con.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }// TODO Auto-generated met

}

ClinicServiceImpl:

public void checkAuthentication(User user) {
    ClassPathXmlApplicationContext ctx = new  ClassPathXmlApplicationContext("clinicconfig.xml");
    userDAO = ctx.getBean("userDAO", UserDAO.class);

    user.setLogin(user.getLogin());
    user.setPassword(user.getPassword());

    userDAO.checkAuthentication(user);

}

Answer 1

diff the two bean, here is an implementation:

public static List<ChangeItem> getChangeItems(Object oldObj, Object newObj) {
        Class cl = oldObj.getClass();
        List<ChangeItem> changeItems = new ArrayList<ChangeItem>();

        try {
            BeanInfo beanInfo = Introspector.getBeanInfo(cl, Object.class);

            for (PropertyDescriptor propertyDescriptor : beanInfo
                    .getPropertyDescriptors()) {
                String fieldname = propertyDescriptor.getName();
                String oldProp = getValue(PropertyUtils.getProperty(oldObj,
                        fieldname));
                String newProp = getValue(PropertyUtils.getProperty(newObj,
                        fieldname));

                if (!oldProp.equals(newProp)) {
                    ChangeItem changeItem = new ChangeItem();
                    changeItem.setField(fieldname);
                    changeItem.setNewValue(newProp);
                    changeItem.setOldValue(oldProp);
                    changeItems.add(changeItem);
                }
            }
        } catch (Exception e) {
            logger.error("There is error when convert changeset", e);
        }

        return changeItems;
    }

Answer 2

You need to do the below changes to make it work.

1) Add a string return type to method checkAuthentication in the class ClinicServiceImpl.java , to identify whether login is "success" or "failure" .

2) Based on this return value in the LoginController.java you can redirect to the appropriate page.

3) In the checkAuthentication method of UserDaoImpl class, you need to check whether any record exist in the DB with the input value username and password.

Code should be as below:

LoginController.java

@RequestMapping(value="/home.html", method = RequestMethod.POST)
public ModelAndView homePagePost(@ModelAttribute("user") User user)
{   
    setAppContext();         
    String result = clinicService.checkAuthentication(user);     

    ModelAndView mav = new ModelAndView();
    if("success".equals(result)) {
       mav.setViewName("Home"); 
    } else {
       mav.setViewName("Login");
    }       
    return mav;
}

ClinicServiceImpl.java:

public String checkAuthentication(User user) {
    ClassPathXmlApplicationContext ctx = new  ClassPathXmlApplicationContext("clinicconfig.xml");
    userDAO = ctx.getBean("userDAO", UserDAO.class);

    user.setLogin(user.getLogin());
    user.setPassword(user.getPassword());

    String result = userDAO.checkAuthentication(user);
    return result;
}

UserDaoImpl:

public String checkAuthentication(User user) {
    String query = "SELECT login, password FROM virtualclinic.user WHERE login=? AND password=?";
    String result = null;
    Connection con = null;
    PreparedStatement ps = null;
    try{
        con = dataSource.getConnection();
        ps = con.prepareStatement(query);
        ps.setString(1, user.getLogin());
        ps.setString(2, user.getPassword());
        ResultSet out = ps.executeQuery();
        out.last();
        int count  = out.getRow();
        if(count==1) {
           result = "success";
        } else {
           result = "failure";
        }
    }catch(SQLException e){
        e.printStackTrace();
    }finally{
        try {
            ps.close();
            con.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }// TODO Auto-generated met
    return result;
}