Ajax – Handling JSON and form data request with Spring MVC

ajaxrestspringspring-mvc

I'm working on simple Spring-MVC application and I love new Spring REST features. I'd like to use the same method to process regular form and JSON data. It seems to be a little tricky, however. For example, method

public @ResponseBody String process(@RequestBody Bean bean);

will work for JSON request (Content-type: application/json), and

public @ResponseBody String process(Bean bean);

will match request with Content-type: application/x-www-form-urlencoded.

These methods are obviously will have almost the same content, so I'd prefer to avoid such duplication. With Jersey it's possible with @Consumes annotations, but I can't figure out how to do it with Spring.

Best Answer

First, the above declaration won't compile, because you are having duplicate signature.

Btw, @Consumes wouldn't help, I think, because it only designates what content type the method can handle.

In spring you can specify the content-type with

@RequestMapping(headers="Content-Type=application/json")

Related Solutions

Rest – HTTP GET with request body

Roy Fielding's comment about including a body with a GET request.

Yes. In other words, any HTTP request message is allowed to contain a message body, and thus must parse messages with that in mind. Server semantics for GET, however, are restricted such that a body, if any, has no semantic meaning to the request. The requirements on parsing are separate from the requirements on method semantics.

So, yes, you can send a body with GET, and no, it is never useful to do so.

This is part of the layered design of HTTP/1.1 that will become clear again once the spec is partitioned (work in progress).

....Roy

Yes, you can send a request body with GET but it should not have any meaning. If you give it meaning by parsing it on the server and changing your response based on its contents, then you are ignoring this recommendation in the HTTP/1.1 spec, section 4.3:

...if the request method does not include defined semantics for an entity-body, then the message-body SHOULD be ignored when handling the request.

And the description of the GET method in the HTTP/1.1 spec, section 9.3:

The GET method means retrieve whatever information ([...]) is identified by the Request-URI.

which states that the request-body is not part of the identification of the resource in a GET request, only the request URI.

Update

The RFC2616 referenced as "HTTP/1.1 spec" is now obsolete. In 2014 it was replaced by RFCs 7230-7237. Quote "the message-body SHOULD be ignored when handling the request" has been deleted. It's now just "Request message framing is independent of method semantics, even if the method doesn't define any use for a message body" The 2nd quote "The GET method means retrieve whatever information ... is identified by the Request-URI" was deleted. - From a comment

From the HTTP 1.1 2014 Spec:

A payload within a GET request message has no defined semantics; sending a payload body on a GET request might cause some existing implementations to reject the request.

Json – How to POST JSON data with cURL

You need to set your content-type to application/json. But -d (or --data) sends the Content-Type application/x-www-form-urlencoded, which is not accepted on Spring's side.

Looking at the curl man page, I think you can use -H (or --header):

-H "Content-Type: application/json"

Full example:

curl --header "Content-Type: application/json" \
  --request POST \
  --data '{"username":"xyz","password":"xyz"}' \
  http://localhost:3000/api/login

(-H is short for --header, -d for --data)

Note that -request POST is optional if you use -d, as the -d flag implies a POST request.

On Windows, things are slightly different. See the comment thread.

Best Answer

Related Solutions

Rest – HTTP GET with request body

Json – How to POST JSON data with cURL

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