英文:
How do I tell Spring to exclude binding an object property?
问题
我有一个Spring控制器方法，有两个对象参数：
@GetMapping
public List<Car> getCars(BlueBookCar blueBookCar, AutoTraderCar autoTraderCar)
BlueBookCar和AutoTraderCar都有一个名为id的字段。我希望在HTTP GET请求中，查询参数名id只绑定到BlueBookCar实例。
例如，以下请求：
http://localhost/cars?id=123
应该导致blueBookCar具有id等于123。而autoTraderCar的id应该为null。但是，Spring设置了两个对象的id都为123。
我该如何告诉Spring排除绑定autoTraderCar的id？其他与查询参数名匹配的autoTraderCar字段应该设置（如Spring通常所做的）。
更新
我想要注意：
- 我不希望HTTP客户端知道存在两种类型的汽车，
BlueBookCar和AutoTraderCar。 - 除了
id之外，两种汽车类型的所有属性都不同。以后可能会有其他属性重叠。 - 出于维护原因和类之间的关系，我不想创建一个包含两个类属性集的第三个类。
ASP.NET MVC支持属性绑定排除。请参阅https://stackoverflow.com/a/8332917/1706691。Spring是否支持这个？
英文:
I have a Spring controller method that has two object params:
@GetMapping
public List<Car> getCars(BlueBookCar blueBookCar, AutoTraderCar autoTraderCar)
Both BlueBookCar and AutoTraderCar have a field named id. I want the query param name id in an HTTP GET request to be bound only to the BlueBookCar instance.
For example, the following:
http://localhost/cars?id=123
Should result in blueBookCar having an id equal to 123. The autoTraderCar id should be null. Instead, Spring sets both objects with an id of 123.
How can I tell Spring to exclude binding id for the autoTraderCar? Other autoTraderCar fields that have names matching query param names should be set (as Spring normally does).
Update
I meant to note that:
- I do not want HTTP clients to be aware of the existence of two types of cars,
BlueBookCar&AutoTraderCar - All properties except
idare different between the two types of car. It's possible that later other properties may overlap. - I do not want to create a third class with the set of properties from both classes for maintenance reasons and because the classes have relationships.
ASP.NET MVC supports property binding exclusions. See https://stackoverflow.com/a/8332917/1706691. Does Spring support this?
答案1
得分: 1
你可以使用@InitBinder来访问WebDataBinder，以自定义如何将HTTP请求中的数据绑定到控制器方法中的特定参数对象。
在你的情况下，添加以下内容应该解决你的问题：
@Controller
public class CarController {
@InitBinder("autoTraderCar")
public void initAutoTraderCarDataBinder(WebDataBinder binder) {
binder.setDisallowedFields("id");
}
@GetMapping
public List<Car> getCars(BlueBookCar blueBookCar, AutoTraderCar autoTraderCar) {
}
}
英文:
You can use @InitBinder which allows you to access WebDataBinder for customising how to bind the data from the http request to a particular parameter object in the controller method.
In your case , adding the following should solve your problem :
@Controller
public class CarController {
@InitBinder("autoTraderCar")
public void initAutoTraderCarDataBinder(WebDataBinder binder) {
binder.setDisallowedFields("id");
}
@GetMapping
public List<Car> getCars(BlueBookCar blueBookCar, AutoTraderCar autoTraderCar){
}
}
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