Keep getting: Neither BindingResult nor plain target object for bean name 'index' available as request attribute

问题

I can't understand what I am doing wrong. I have a controller:

@Controller
@RequestMapping(value = "/index.htm")
public class LoginController {

    @Autowired
    private AccountService accountService;

    @RequestMapping(method = RequestMethod.GET)
    public String showForm(Map model) {
        model.put("index", new LoginForm());
        return "index";
    }

    @ModelAttribute("index")
    public LoginForm getLoginForm() {
        return new LoginForm();
    }

    @RequestMapping(method = RequestMethod.POST)
    public String processForm(LoginForm loginForm, BindingResult result,
                              Map model) {

        if (result.hasErrors()) {
            HashMap<String, String> errors = new HashMap<String, String>();
            for (FieldError error : result.getFieldErrors()) {
                errors.put(error.getField(), error.getDefaultMessage());
            }
            model.put("errors", errors);
            return "index";
        }

        List<Account> accounts = accountService.findAll();
        loginForm = (LoginForm) model.get("loginForm");


        model.put("index", loginForm);
        return "loginsuccess";
    }

}

And Spring html form:

<form:form action="index.htm" commandName="index">

    <table cellspacing="10">
        <tr>
            <td>
                <form:label path="username">
                    <spring:message code="main.login.username"/>
                </form:label>
            </td>
            <td>
                <form:input path="username" cssClass="textField"/>
            </td>
        </tr>
        <tr>
            <td>
                <form:label path="password">
                    <spring:message code="main.login.password"/>
                </form:label>
            </td>
            <td>
                <form:password path="password" cssClass="textField"/>
            </td>
        </tr>
        <tr>
            <td>
                <input type="submit" class="button" value="Login"/>
            </td>
        </tr>
    </table>

</form:form>

When I try to access URL: http://localhost:8080/webclient/index.htm

I keep getting this exception:

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'index' available as request attribute

What is wrong with my controller and why I keep getting an exception like that?

回答1:

I would make the following changes. First your GET method should be something like:

@RequestMapping(method = RequestMethod.GET)
public String showForm(@ModelAttribute("index") LoginForm loginForm) {
    return "index";
}

Using the @ModelAttribute annotation will automatically put "index" into the model for the request.

And your POST method declaration should be something like:

@RequestMapping(method = RequestMethod.POST)
public String processForm(@ModelAttribute("index") LoginForm loginForm, 
                          BindingResult result, Map model) {

Finally, and probably the real issue, change the controller class's @RequestMapping annotation to:

@RequestMapping(value = "/index")

The ".htm" that you have is redundant. You've already configured web.xml and your Spring config to respond to ".htm" requests.

来源：https://stackoverflow.com/questions/12585790/keep-getting-neither-bindingresult-nor-plain-target-object-for-bean-name-index

标签

java

Spring

spring-mvc

controller