UriTemplateHandler is not called for requests without url variables [SPR-13145]

[spring-projects-issues]

Jiri Mikulasek opened SPR-13145 and commented

In #17627 some baseUrl - prepending mechanism was introduced in DefaultUriTemplateHandler. When verifying that I unfortunately missed the situation when restTemplate called with URL without some variables and it seems in that situation the UriTemplateHandler is not invoked at all, which results to inconsistent behaviour.

Please make it consistent - either move the baseUrl prefixing mechanism somewehere else (which is invoked for every request) or invoke the UriTemplateHandler for each request.

Sorry for not realizing this problem at the beginning.

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Affects: 4.2 RC1

Issue Links:

• Ability to prefix each RestTemplate request using some kind of UriPrefixingClientHttpRequestFactory [SPR-13035] #17627 Ability to prefix each RestTemplate request using some kind of UriPrefixingClientHttpRequestFactory

[spring-projects-issues]

Rossen Stoyanchev commented

On taking a closer look I'm not sure this is feasible. The methods that accept a String-based URI template offer the convenience of providing a simple string with URI variables that we assemble and encode to arrive at a URI. If makes sense as part of that to provide additional options such as prepending a common prefix.

The methods that accept a URI, expect a fully prepared URI that should be used as is. The idea is that if the String-based URI template option doesn't work for some reason, you always have the choice to use the URI alternatives. So I don't think we want to touch that URI.

That said for your use case I recommend following a similar approach. If users of your REST API choose to provide a URI they should make sure it's complete and you could assist them with building that URI for example through some utility methods or class. Alternatively you could also extend the RestTemplate and override the necessary methods to make it more transparent.

[spring-projects-issues]

Jiri Mikulasek commented

Inspite of that I understand your point of view, what I originally wanted in 13035, was to prefix each request URI passing through RestTemplate. So can you please consider if there is still some possibility to provide some way for that?

To me it seems not very nice, when using RestTemplate, to think carefully about each method call whether I use UriTemplate or plain URI and let prefixing on it or rather to do it ourselves.

[spring-projects-issues]

Rossen Stoyanchev commented

Do you actually have java.net.URI passed in that requires prefixing? I'm wondering why not stick to using the String-based URI template methods? In other words is there an underlying reason for using the URI-based methods (something to do with encoding perhaps, or using an alternative URI templating mechanism)?

Usage-wise those are two parallel sets of methods. You can completely ignore those accepting a URI for example. That's not the same as having to think carefully about each method.

[spring-projects-issues]

Jiri Mikulasek commented

Sorry for delayed answer, caused by ongoing dicussion with colleagues.

Well, let's close this - your point of view about URI-based methods is acceptable for us. Thanks for time anyway.

[spring-projects-issues]

Rossen Stoyanchev commented

Thanks for the answer.