如何在Spring Rest MVC中强制使用bean请求参数？

Question

I'm using Spring 5 for a REST API and I can't get how to mark request parameters required so that Spring would reply 400 Bad request instead of letting the request reach the controller method.

My methods use a bean to receive query string parameters, so @RequestParam(required=true) is not an option here:

@GetMapping(path="")
public String findAll(Filter filter) {
    // ...
}

A Filter looks like this:

public class Filter {

    private String id;

    private String usersId;

    private GregorianCalendar dayStart;

    private GregorianCalendar dayEnd;

    // ...

}

I'd like to require ie just usersId to be mandatory.

Is there anything like that or should I manually validate the input?

Answer 1

You could use something like this

@GetMapping(path="")
public String findAll(@Valid Filter filter) {
    // ...
}

And on your Filter class

public class Filter {

    private String id;
    @NotNull
    private String usersId;
    private GregorianCalendar dayStart;
    private GregorianCalendar dayEnd;

    // ...

}

You should also make sure that

• Validation is enabled
• Your bean is instantiated in such a way the validation rules are applied

Answer 2

You can user javax.validation.Valid to validate your bean and instead of using @GetMapping you can use @PostMapping .

@PostMapping(path="")
public String findAll(@Valid Filter filter) {
    // ...
}

and in your Filter class you can use @NotNull of javax.validation.constraints.NotNull and @NotEmpty of javax.validation.constraints.NotEmpty

public class Filter {

    private String id;

    @NotNull
    @NotEmpty
    private String usersId;

    private GregorianCalendar dayStart;

    private GregorianCalendar dayEnd;

    // ...
}

For more detail for validation look at here