Question

我正在尝试使用 @ModelAttribute 绑定数据。我有两个名为Address和Student的用户定义类。这两个数据类的结构如下：

Address.java ：

package org.manya.dataClasses;

public class Address {

    private String city;
    private String state;

    public Address(String city,String state)
    {
        this.city = city;
        this.state = state;
        System.out.println("from the constructor of Address");
    }

    public Address()
    {
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

}

Student.java ：

package org.manya.dataClasses;

public class Student {

    private String name;
    private int age;
    private Address studentAddress;

    public Student(String name,int age,Address studentAddress)
    {
        System.out.println("from the constructor of Student = ");
        if(studentAddress == null)
        {
            System.out.println("address is null");
        }
        this.name = name;
        this.age = age;
        this.studentAddress= studentAddress;
    }

    public Student()
    {

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public Address getAddress() {
        return studentAddress;
    }

    public void setAddress(Address studentAddress) {
        this.studentAddress = studentAddress;
    }

}

使用@ModelAttribute我试图绑定学生对象，但仅限于 String和int属性被绑定，但 Address依赖项仅为null。

web.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
      <display-name>Archetype Created Web Application</display-name>

     <servlet>
        <servlet-name>frontController</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
     </servlet>

     <servlet-mapping>
        <servlet-name>frontController</servlet-name>
        <url-pattern>/</url-pattern>
     </servlet-mapping>

    </web-app>

**frontController-servlet.xml**

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context = "http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context-3.0.xsd
                        http://www.springframework.org/schema/mvc
                        http://www.springframework.org/schema/mvc/spring-mvc.xsd">


    <context:annotation-config/>
    <context:component-scan base-package="org.manya.Controllers"></context:component-scan>
    <mvc:annotation-driven/>
    <!-- <mvc:resources location="/resources/**" mapping="/home/*"></mvc:resources>
 -->

    <mvc:resources location="/resources/**" mapping="/static/**"/>
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
    <!-- <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/resources/"/>
        <property name="suffix" value=".html"/>
    </bean> -->

</beans>

StudentController.java

package org.manya.Controllers;

import org.manya.dataClasses.Address;
import org.manya.dataClasses.Student;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping("/student")
public class StudentController {


    @GetMapping("/studentForm")
    public String admissionForm()
    {
        return "admissionForm";
    }

    @PostMapping("/submitted")
    public ModelAndView submitted(@ModelAttribute("student") Student stud)
    {
        ModelAndView mv = new ModelAndView("submitted");
        return mv;

    }
}

admissionForm.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

<!-- <form action="./submitted" method="post">
    NAME : <input name="name"/>
    AGE : <input name="age"/>
    CITY : <input type="text" name="city"/>
    STATE : <input type="text" name="state"/>
    SUBMIT : <input type="submit"/>
</form> -->


<form action="./submitted" method="post">
    NAME : <input name="name"/>
    AGE : <input name="age"/>
    CITY : <input type="text" name="studentAddress.city"/>
    STATE : <input type="text" name="studentAddress.state"/>
    SUBMIT : <input type="submit"/>
</form>

</body>
</html>

Answer 1

In the Student class you have getter and setter for studentAddress field as getAddress() and setAddress. I think you need to change these method names to getStudentAddress() and setStudentAddress(). Let me know if it works.

Spring MVC @ModelAttribute不使用用户定义的依赖项

1 个答案: