java - 在 Spring MVC(使用 hibernate Validator)中提交带有无效数据的表单时发送语法错误的请求

Question

登录表单:

<f:form class="form-horizontal" method="post" action="/login"
    commandName="logindata">
    <fieldset>
        <legend class="text-info">Login</legend>
        <div class="control-group">
            <f:label path="uname" class="control-label" for="uname">Username</f:label>
            <div class="controls">
                <f:input type="text" path="uname" name="uname" id="uname"
                    placeholder="Username" />
            </div>
        </div>
        <div class="control-group">
            <f:label path="pwd" class="control-label" for="pwd">Password</f:label>
            <div class="controls">
                <f:input type="password" path="pwd" name="pwd" id="pwd"
                    placeholder="Password" />
            </div>
        </div>
        <div class="control-group">
            <div class="controls">
                <button type="submit" class="btn" id="login">
                    Login <i class="icon-chevron-right"></i>
                </button>
            </div>
        </div>
        <div id="errormsg" class="alert alert-error">${message}</div>
    </fieldset>
</f:form>

登录数据类:

package com.demo.forms;

import org.hibernate.validator.constraints.Length;
import org.hibernate.validator.constraints.NotEmpty;

public class loginData {
    @Length(min=4)
    private String uname; 

    @NotEmpty
    private String pwd;

    public String getUname() {
        return uname;
    }
    public void setUname(String uname) {
        this.uname = uname;
    }
    public String getPwd() {
        return pwd;
    }
    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}

用于显示和提交表单的 Controller 方法:(显示包含注册表单和登录表单的主页)

@RequestMapping(value = "/", method=RequestMethod.GET)
    public String showHome(Model model)
    {
        loginservice.logout();
        model.addAttribute("logindata", new loginData());
        model.addAttribute("signupdata", new signupData());
        return "home";
    }

提交登录表单时调用的方法:

@RequestMapping(value = "login", method=RequestMethod.POST)
    public String submitloginForm(@Valid loginData logindata, SessionStatus state, Model model, BindingResult result)
    {
            if((loginservice.loggedin()) || (result.hasErrors()))
            {
                return showHome(model);
            }
            else
            {
                String uname = logindata.getUname();
                String pwd = logindata.getPwd();
                if(loginservice.login(uname, pwd))
                {
                    model.addAttribute("user",uname);
                    return "redirect:profile";
                }
                else
                {
                    model.addAttribute("message","Invalid Username/Password");
                    return showHome(model);
                }   
            }   
    }

当输入的数据“有效”(正确或错误)时，登录工作正常。但是，当它无效时，例如，当密码字段为空或用户名长度少于四个字符时，会显示以下错误:

The request sent by the client was syntactically incorrect.

知道如何解决这个问题吗？

Answer 1

您必须修改参数的顺序。始终将 BindingResult 结果 参数直接放在带有 @Valid 注释的参数之后。

@RequestMapping(value = "login", method=RequestMethod.POST)
public String submitloginForm(@Valid loginData logindata, BindingResult result,
                              SessionStatus state, Model model)

这甚至在这几周被提及 This Week in Spring - March 5th, 2013博客条目

Someone asked me this the other day and I felt like it was worthy of a mention: in your Spring MVC @Controller class handler methods, make sure that the BindingResult argument is immediately after the model or command argument, like this: @RequestMapping(...) public String handleRequest( @ModelAttribute @Valid YourCustomPojo attempt, BindingResult result). In this example, handleRequest will validate the POJO (YourCustomPojo) - checking the POJO for JSR303-annotations and attempting to apply the constraints because the POJO is annotated with @Valid - and stash any errors in the BindingResult, which it makes available if we ask for it.

春将

• 0) 确定处理程序方法
• 1) 创建一个 loginData 实例
• 2) 填充它
• 3) 对其进行验证，并将验证结果存储在BindingResult中
• 4) 调用方法(使用 loginData 和 BindingResult 值)，无论绑定(bind)结果是否包含错误