Is there a way to access HttpRequest type inside a @Controller method

Question

I have tried to find the answer to this, but I cannot seem to find what I am looking for. So I apologize if this question already exists.

PROBLEM:
I want to be able to access the request type of a request inside of a generic method within my Controller.

DESCRIPTION:
Using Spring ROO and Spring MVC, I have developed a small web service that will respond with certain tidbits from a database when queried. In one of my controller classes, I have some methods that handle some variety of GET, PUT, POST, etc., for the URIs that are mapped within the @RequestMapping parameter.

For example:

@RequestMapping(method = RequestMethod.Get, value = "/foo/bar")
@ResponseBody
public ResponseEntity<String> getFooBar() {
    // stuff
}

If a request is made to the web service that it is not currently mapped, a 405 error is returned (which is correct), but I want to return more information along with a 405 response. Maybe respond with something like:

"I know you tried to execute a [some method], but this path only handles [list of proper methods]."

So I wrote a short method that only has the RequestMapping:

@RequestMapping(value = "/foo/bar")

I have found that the method with this mapping will catch all unhandled request types. But I am having trouble accessing the information of the request, specifically the type, from within the method.

QUESTION:
A. How can I access the request type from within the method?
OR
B. Is this the right approach? What would be the right approach?

EDIT
ANSWER:

I added a HttpServletRequestobject to the method parameters. I was able to access the method type from that.

I tried using HttpRequest, but it didn't seem to like that much.

Thanks all!

I guess just declaring a method parameter of type `HttpRequest` should work. — Henry, Nov 12 '13 at 14:21

score 2 · Accepted Answer · edited May 23 '17 at 12:12

2

You can add a method parameter of HttpServletRequest, but I think you'd be better off continuing to reply with 405. A client should then make an HTTP OPTIONS call (see How to handle HTTP OPTIONS with Spring MVC?) and you can return the list of allowed methods there.

edited May 23 '17 at 12:12

Community

1
1

answered Nov 12 '13 at 14:38

artbristol

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Thanks! I was trying to use HttpEntity<>, but it did not have the information I needed. I will look into implementing an OPTIONS request, but I didnt mean to imply that I would stop replying with a 405. I just want to send more information along with the 405. This request is just meant to be a fallback request in case they dont hit anything else. Also, it didnt seem to like `HttpRequest`, but it liked `HttpServletRequest` – Vae Nov 12 '13 at 14:47
@Vae you're right, it should be `HttpServletRequest`, updated answer. – artbristol Nov 12 '13 at 15:01

score 0 · Answer 2 · answered Nov 12 '13 at 14:43

0

A. you can access request if you mentioned it as parameter in controller method

public ... getFooBar(HttpRequest request) {
...
}

B. you do not need to add any other description as the 405 status is descriptive.

answered Nov 12 '13 at 14:43

Bassem Reda Zohdy

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Steve · Answer 3 · 2013-11-12T14:55:06.713

In answer to "A", just add "HttpRequest req" as an additional argument to your controller methods. Spring will automatically inject a reference to the request, and you can play with headers to your heart's content.

In answer to "B" - "What would be the right approach", how about this?

In order to return that 405, Spring has raised a MethodArgumentNotValidException. You can provide custom handling for this like so:

@ExceptionHandler(MethodArgumentNotValidException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
@ResponseBody
public MyMethodArgumentMessage handleMathodArgumentNotValidException(
        MethodArgumentNotValidException ex) {
    BindingResult result = ex.getBindingResult();
    MyMethodArgumentMessage myMessage = 
            new MyMethodArgumentMessage(result.getFieldErrors());
    return myMessage;
}

You should take a look at the @ExceptionHandler annotation. This lets you add methods such as the following to your controller. You can define your own exceptions and appropriate custom handlers for them. I use it to return well-structured XML and JSON from REST services. Although for it to work, you need to throw specific exceptions from your controller methods.

A good walk-through of using this was provided by Petri Kainulkainen in his blog: http://www.petrikainulainen.net/programming/spring-framework/spring-from-the-trenches-adding-validation-to-a-rest-api/

btw - Petri Kainulainen wrote a good blog post on this here: http://www.petrikainulainen.net/programming/spring-framework/spring-from-the-trenches-adding-validation-to-a-rest-api/ — Steve, Nov 12 '13 at 14:46

Is there a way to access HttpRequest type inside a @Controller method

3 Answers3