RestTemplate - access to Request Headers [SPR-5866]

[spring-projects-issues]

Graham Zabel opened SPR-5866 and commented

Hi,

When sending GET and POST requests, we are required to send a Security token in the HTTP header. Currently with RestTemplate there is no easy way to set headers on the request.

The only way that seems possible is to provide a custom RequestCallback, in which the httpRequest object can be manipulated in doWithRequest(), making all but the execute() method unusable.

Is there a clean and easy way to set http headers on requests? (I can't think of one without some significant rewrites).

thanks,
Graham

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Issue Links:

• Introduce HttpEntity [SPR-6969] #11634 Introduce HttpEntity ("depends on")

2 votes, 6 watchers

[spring-projects-issues]

Arjen Poutsma commented

Currently there is no way to do this easily, but we could introduce an interceptor mechanism. Something similar to

http://static.springframework.org/spring-ws/sites/1.5/apidocs/org/springframework/ws/client/support/interceptor/ClientInterceptor.html

[spring-projects-issues]

Arjen Poutsma commented

Rescheduling to 3.1.

[spring-projects-issues]

Christian Tzolov commented

This is an essential feature if the RestTemplate is to be used in real production environments.

[spring-projects-issues]

Arjen Poutsma commented

It's possible to add request headers with a RequestCallback using the execute method, and to use the HttpMessageConverterExtractor to resolve response extraction. Granted, it's not as easy as the other methods of the RestTemplate, but it works now, before we introduce the interceptor functionality scheduled for 3.1.

[spring-projects-issues]

Christian Tzolov commented

Thanks for the tip Arjen. I've put together a very simple RestTemplate extension that could help in certain scenarios that require http request header access: http://tzolov.blogspot.com/2010/03/spring-3-resttemplate-access-to-request.html

[spring-projects-issues]

Arjen Poutsma commented

Rescheduling for 3.0.2

[spring-projects-issues]

Arjen Poutsma commented

With the introduction of HttpEntity, this turned out to be pretty easy. I've introduced an 'exchange method', with which you can do the following:

HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("MyHeader", "MyValue");
HttpEntity<?> requestEntity = new HttpEntity(requestHeaders);
HttpEntity<String> response = template.exchange("http://example.com", HttpMethod.GET, requestEntity, String.class);
System.out.println(response.getBody());

or

HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("MyHeader", "MyValue");
HttpEntity<String> requestEntity = new HttpEntity<String>(helloWorld, requestHeaders);
HttpEntity<?> result = template.exchange("http://example.com", HttpMethod.POST, requestEntity, null);
System.out.println(result.getHeaders().getLocation());
System.out.println(result.hasBody()); // prints false, since the response body was empty

This will be in 3.0.2, please try a recent snapshot and see how you like it.

[spring-projects-issues]

Duane Zamrok commented

It's a shame you didn't end up implementing this using interceptors. I find the interceptors that are on WebServiceTemplate and other framework classes to be invaluable, and was disappointed to see that the RestTemplate does not have one. I tend to dislike AOP, but without interceptors I guess I'm forced to use it.

[spring-projects-issues]

Arjen Poutsma commented

@Duane: we might still do interceptors :).

[spring-projects-issues]

Duane Zamrok commented

I so greatly desired interceptors that I have put together an implementation of RestTemplate which uses them.

I "borrowed" liberally from spring-ws (Arjen specifically) in my implementation, but I had to roll my own interceptor interfaces and the message context, because of some of the differences between traditional WS and REST. I'd love to submit this back to the project, either for you to laugh at or use, but don't really know what the process for doing so would be. Please advise as to whether you think such an effort would yield anything valuable.

Thanks

[spring-projects-issues]

Arjen Poutsma commented

@Duane: I have created #12152 to add interceptors to the RestTemplate. You can simply comment and/or attach your code there.