SessionAttributes上的Spring Boot不工作

Question

我在SpringBoot项目中有一个控制器类，它具有登录功能。当我输入用户名和密码并按submit时，它将使用method=“POST”调用LoginController。我希望当我使用模型添加属性“customer”时，“customer”属性也将通过@SessionAttributes（“customer”）添加到会话中。相反，它返回错误

这里是错误

Expected session attribute 'customer'
org.springframework.web.HttpSessionRequiredException: Expected session attribute 'customer'

这是我的密码

@Controller
@SessionAttributes("customer")
public class LoginController {
    
    @Autowired
    CustomerService customService;
    
    @RequestMapping(method=RequestMethod.GET,value="/login")
    public String login() {
        
        return "login";
    }
    
    @RequestMapping(method=RequestMethod.POST,value="/login")
    public String submitLoginForm(@ModelAttribute Customer customer, Model model) {
                
        model.addAttribute("customer", customService.getCustomer(customer.getUsername(), customer.getPassword()));
                
        return "redirect:/";
    }
    
}```

Answer 1

您必须使用@ModelAttribute（“客户”）

对于eg：

@Service
public class CustomerService {

    @ModelAttribute("customer")
    public Customer getCustomer(String username, String password) {
        return new Customer(username, password);
    }

}

模型对象

public class Customer {

    private String username;
    private String password;

    public Customer(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }

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

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

}

控制器

@Controller
@SessionAttributes("customer")
public class LoginController {
    
    @Autowired
    CustomerService customService;
    
    @RequestMapping(method=RequestMethod.GET,value="/login")
    public String login() {    
        return "login";
    }
    
    @RequestMapping(method=RequestMethod.POST,value="/login")
    public String submitLoginForm(Customer customer, Model model, HttpServletRequest request) {            
        model.addAttribute("customer", customService.getCustomer(customer.getUsername(), customer.getPassword()));
        return "redirect:/";
    }
     
}