Spring MVC的问题。如何从两个或多个对象创建视图？

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问题描述

[春季3.0.5]
[jboss 5.1]

[spring 3.0.5][jboss 5.1]

A有两个类

public class User {
 private String name;
 private String surname;
 private Address address;
...
sets and gets 
setters and getters  
}

public class Address {
 private String street;

...
setters and getters  
}

在Controller中我有这个代码：

In Controller I have this code:

@Controller 
public class MyController {

@RequestMapping(value = "/index")
public ModelAndView showForm() {
ModelAndView mav = new ModelAndView();
mav.setViewName("index");
User user = new User();
Address adr = new Address();
mav.addObject("user", user);
mav.addObject("adr", adr);
}

现在我想用JSP中的两个输入元素创建

And now I want to create from with two input element in JSP

<%@taglib uri="http://www.springframework.org/tags" prefix="spring"%> <%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>

    <html><head><body>
    <form:form method="POST" commandName="user">
    <form:label path="name" />
    <form:input path="name" />
    <form:label path="adr.street" />
    <form:input path="adr.street" />
    </form:form>
    </body>
    </html>

当我运行一个像这样的例外时：

When I runing a got a exception like this one:

org.springframework.beans.NotReadablePropertyException：bean类[form.User]的属性'adr'无效：Bean属性'adr'不可读或getter方法无效：getter的返回类型是否匹配setter的参数类型？
org.springframework.beans.BeanWrapperImpl.getPropertyValue（BeanWrapperImpl.java:707）
org.springframework.be

org.springframework.beans.NotReadablePropertyException: Invalid property 'adr' of bean class [form.User]: Bean property 'adr' is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter? org.springframework.beans.BeanWrapperImpl.getPropertyValue(BeanWrapperImpl.java:707) org.springframework.be

有人可以向我解释为什么以及如何改进代码？

Can someone please explain to me why and how to improve the code?

推荐答案

将对象包装在包装器表单类中并将其传递给模型。

Wrap your objects in a wrapper form class and pass it in the model.

public class MyForm
{
   public user;
   public address;
   // getters, setters, etc.
}

然后

ModelAndView mav = new ModelAndView(); // ModelAndView
mav.addObject("myForm", new MyForm()); // e.g.

在您的模型中，地址是否应附加给用户？换句话说，在我看来，像用户与地址有一对多的关系，你应该让您的数据访问层处理这些问题。

In your model, should address be attached to a user? In other words, it seems to me like a User has a one to many relationship to Address, and you should let your data access layer handle these concerns.

@Entity
@Table(name = "user")
public class User
{
   @Id @Column(name="user_id")
   public Long id;

   @OneToMany
   @JoinColumn(name = "user_id") // so the address table would have a user_id foreign key
   public Address address;
}

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