th:if =" $$ ## fields.hasErrors()}"导致异常评估SpringEL表达式 [英] th:if="${#fields.hasErrors()}" causes Exception evaluating SpringEL expression

问题描述

正如大家所看到的，我正在尝试对表单的1个字段进行验证:

I'm trying to do validation on 1 field of the form as you guys can see:

<div id ="EditModal" class="modal fade" role="dialog">
    <form class="modal-dialog" th:action="@{/Edit}" th:object="${person1}" method="POST">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal">&times;</button>
            </div>
            <div class="modal-body">
                <input type="hidden" id="edit-modal-person-id" name="id" value=""/>
                <input type="text" placeholder="Name" id="edit-modal-person-name" name="name"/>
                <p th:if="${#fields.hasErrors('name')}" th:errors="*{name}" th:class="'error'">something</p>
                <div>
                    <a class="btn btn-default pull-right" id="PhoneNumberEdit">Edit Phone Number</a>
                </div>
            </div>
            <div class="modal-footer">
                <button type="submit" id="SubmitEdit" class="btn btn-default" >Submit</button>
                <button type="button" class = "btn btn-default" data-dismiss="modal">Cancel</button>
            </div>
        </div>
    </form>
</div>

属性th:if="${#fields.hasErrors('name')}"总是对我造成500错误.

the attribute th:if="${#fields.hasErrors('name')}" always causes the 500 error for me.

我的控制器:

@RequestMapping(value = "/Edit", method = RequestMethod.POST)
public String editPerson(@Valid @ModelAttribute(value="person1") PersonRequest person, BindingResult result) {
    if(result.hasErrors()) {
        return "redirect:All";
    }
    else {
        personService.update(person.getId(), person.getName());
        return "redirect:All";
    }
}

我的实体:

public class PersonRequest {

    @NotNull
    private long id;

    @NotEmpty
    @Name
    private String name;

    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public PersonRequest() {
        super();
    }
}

控制台返回以下错误:

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'person1' available as request attribute.

但是我认为这与它无关，因为如果我删除p标签，它将正常运行.

But I think that doesnt have anything to do with this because if I remove p tag it runs normally.

推荐答案

问题是您进行了重定向，(您进行了"redirect:All"). 由于重定向，您不会传递对象person1，因此错误"java.lang.IllegalStateException:BeanResult'person1'的BindingResult或普通目标对象都不能用作请求属性".

The problem is that you make a redirect, (you make a "redirect:All"). Because of the redirect, you do not pass object person1 thus the error "java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'person1' available as request attribute".

如果您要发布/all requestMapping的代码

If you want post the code of the /all requestMapping that you have

可能您想要这样的东西

@RequestMapping(value = "/Edit", method = RequestMethod.POST)
    public String editPerson(@Valid @ModelAttribute(value="person1") PersonRequest person, BindingResult result) {
        if(result.hasErrors()) {

            return "edit";//change it to the name of the html page that you want to go
        }
        else {
            //probably here you return in the page with all the persons 
            personService.update(person.getId(), person.getName());
            return "redirect:All";
        }
    }

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