Question

我正在尝试创建一个程序，我收到错误

edit.jsp文件

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<body>
<c:if test="${session_username != null }">Hello ${session_username}!</c:if>
    <font face="verdana" size="2">
        ${welcomeMessage} <BR><BR>
        <form:form action="${pageContext.request.contextPath}/editemployee" method="POST" modelAttribute="editForm">
            <form:errors path="studenterrors" />
            <table>
                <tr>
                    <td colspan="2" align="center">Spring MVC Form Demo - Edit</td>
                </tr>
                <tr>
                    <td>User Name</td>
                    <td><form:input path="username" /></td>
                </tr>
                <tr>
                    <td>First Name</td>
                    <td><form:input path="firstname" /></td>
                </tr>
                <tr>
                    <td>Last Name</td>
                    <td><form:input path="lastname" /></td>
                </tr>
                <tr>
                    <td>Mobile No.</td>
                    <td><form:input path="mobileno" /></td>
                </tr>
                <tr>
                    <td>Password</td>
                    <td><form:password path="password" /></td>
                </tr>
                <tr>
                    <td>Email</td>
                    <td><form:input path="email" /></td>
                </tr>
                <tr>
                    <td>BirthDate (mm/dd/yyyy)</td>
                    <td><form:input path="birthdate" /></td>
                </tr>
                <tr>
                    <td>Profession</td>
                    <td><form:select path="profession" items="${professionList}" /></td>
                </tr>
                <tr>
                    <td colspan="2" align="center"><input type="submit" value="Submit" /></td>
                </tr>                                   
            </table>                                        
        </form:form>
    </font> 
</body>
</html>

LoginSuccess.java

package java4s;


import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpSession;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import java4s.EmployeeService;

@Controller
public class LoginSuccessController {

    @Autowired
    EmployeeService emp_service;

    @RequestMapping(value = "/editemployee", method=RequestMethod.POST)
    public ModelAndView EditSaveMyInfo(ModelMap model, @ModelAttribute("editForm") Employee employee) {

        model.addAttribute("message", "Information Updated");
        return new ModelAndView("EditSuccess",model);
    }

}

每当我点击提交按钮时，都会出现HTTP Status 400 -错误。但是当我从函数@ModelAttribute("editForm") Employee employee中删除EditSaveMyInfo时，错误不会出现？

如何解决错误？

修改

Employee.java

package java4s;

import java.util.Date;

public class Employee {

    private String userid;
    private String firstname;
    private String lastname;    
    private String mobileno;
    private String username;
    private String password;
    private String email;
    private Date birthDate;
    private String profession;
    private String studenterrors;

    public String getUserid()
    {
        return userid;
    }
    public void setUserid(String userid)
    {
        this.userid = userid;
    }

    public String getUsername()
    {
        return username;
    }
    public void setUsername(String username)
    {
        this.username = username;
    }
    public String getFirstname()
    {
        return firstname;
    }
    public void setFirstname(String firstname)
    {
        this.firstname = firstname;
    }
    public String getLastname()
    {
        return lastname;
    }
    public void setLastname(String lastname)
    {
        this.lastname = lastname;
    }
    public String getMobileno()
    {
        return mobileno;
    }
    public void setMobileno(String mobileno)
    {
        this.mobileno = mobileno;
    }

    public String getPassword()
    {
        return password;
    }
    public void setPassword(String password)
    {
        this.password = password;
    }
        public String getEmail()
    {
        return email;
    }
    public void setEmail(String email)
    {
        this.email = email;
    }
        public Date getBirthdate()
    {
        return birthDate;
    }
    public void setBirthdate(Date birthDate)
    {
        this.birthDate = birthDate;
    }
        public String getProfession()
    {
        return profession;
    }
    public void setProfession(String profession)
    {
        this.profession = profession;
    }
        public String getstudenterrors()
    {
        return studenterrors;
    }
    public void setstudenterrors(String studenterrors)
    {
        this.studenterrors = studenterrors;
    }
}

Answer 1

使用@RequestBody @Valid Employee employee代替@ModelAttribute("editForm") Employee employee

你控制器变成

@RequestMapping(value = "/editemployee", method=RequestMethod.POST)
    public ModelAndView EditSaveMyInfo(ModelMap model, @RequestBody @Valid Employee employee,BindingResult result) {
    if (result.hasErrors()) {
        throw new BadRequestException();
    }   model.addAttribute("message", "Information Updated");
        return new ModelAndView("EditSuccess",model);
    }

绑定结果对象用于捕获错误请求异常。这是春季标准

Answer 2

您的问题是表单与模型（Employee）之间的绑定失败。

更改您的控制器（只是仔细阅读，您将获得有关绑定实际如何工作的图片）：

package java4s;

import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpSession;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import java4s.EmployeeService;

@Controller
public class LoginSuccessController {

    @Autowired
    EmployeeService emp_service;

   //Give you a form (edit.jsp) as response after binding happens
   @RequestMapping(value = "/employeeform", method=RequestMethod.POST)
    public ModelAndView doBinding() {
       ModelAndView mv = new ModelAndView("edit", "employee", new Employee()); 
            return mv;

    }


  // Now the form comes here after it gets submitted.
 // And you can start populating the fields
    @RequestMapping(value = "/saveemployee", method=RequestMethod.POST)
    public ModelAndView EditSaveMyInfo(ModelMap model, @ModelAttribute("employee") Employee employee) {

        model.addAttribute("message", "Information Updated");
        return new ModelAndView("EditSuccess",model);
    }

}

将您的edit.jsp更改为：

（请注意模型属性已更改为 modelAttribute="employee"，因为我将其与new ModelAndView("edit", "employee", new Employee());控制器中的doBinding(...)进行了映射
我将action=..路径更改为 / saveemployee

在 spring-servlet.xml 中添加<context:annotation-config /> xmlns:context="http://www.springframework.org/schema/context"中的<beans..以启用它。

       <%@page contentType="text/html" pageEncoding="UTF-8"%>
        <%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
        <%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
        <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
        <html>
        <body>
        <c:if test="${session_username != null }">Hello ${session_username}!</c:if>
            <font face="verdana" size="2">
                ${welcomeMessage} <BR><BR>
                <form:form                action="${pageContext.request.contextPath}/saveemployee" method="POST" modelAttribute="employee">
                    <form:errors path="studenterrors" />
                    <table>
                        <tr>
                            <td colspan="2" align="center">Spring MVC Form Demo - Edit</td>
                        </tr>
                        <tr>
                            <td>User Name</td>
                            <td><form:input path="username" /></td>
                        </tr>
                        <tr>
                            <td>First Name</td>
                            <td><form:input path="firstname" /></td>
                        </tr>
                        <tr>
                            <td>Last Name</td>
                            <td><form:input path="lastname" /></td>
                        </tr>
                        <tr>
                            <td>Mobile No.</td>
                            <td><form:input path="mobileno" /></td>
                        </tr>
                        <tr>
                            <td>Password</td>
                            <td><form:password path="password" /></td>
                        </tr>
                        <tr>
                            <td>Email</td>
                            <td><form:input path="email" /></td>
                        </tr>
                        <tr>
                            <td>BirthDate (mm/dd/yyyy)</td>
                            <td><form:input path="birthdate" /></td>
                        </tr>
                        <tr>
                            <td>Profession</td>
                            <td><form:select path="profession" items="${professionList}" /></td>
                        </tr>
                        <tr>
                            <td colspan="2" align="center"><input type="submit" value="Submit" /></td>
                        </tr>                                   
                    </table>                                        
                </form:form>
            </font> 
        </body>
        </html>

现在请求表格 - ＆gt; ..... / employeeform
表单提交后转到 - ＆gt; EditSaveMyInfo()（ action =“/ saveemployee”）

注意：我不希望我的答案直接解决您的问题（因为错误可能来自您的代码中的其他地方），但我只是希望您在spring mvc中获得绑定过程

Answer 3

HTTP STATUS 400表示从前端传递到后端的参数有问题。 @ModelAttribute告诉从会话中获取值，我想使用@RequestParam应该在你的情况下使用，这是从http请求获取参数。

@RequestMapping(value = "/editemployee", method=RequestMethod.POST)
public ModelAndView EditSaveMyInfo(ModelMap model, @RequestParam("employee") Employee employee) {
    model.addAttribute("message", "Information Updated");
    return new ModelAndView("EditSuccess",model);
} 

<form:form action="${pageContext.request.contextPath}/editemployee" method="POST">

Spring MVC HTTP状态400 -

3 个答案: