Can Spring EL be used as an effective query language?

Question

Does anyone know if spel can be used as a query language in the same way that you could with say xpath?

My use case is that I am using a Spring RestTemplate to make a http request to integration test an app we are writing. The response data is json, and rather than create a small handful of domain classes that the response binds to, I am binding the response to a standard java.util.Map

A (simplified) typical response might look like this:

{
    'links': [
        {
            'rel':'self', 
            'href':'http://somesite.com:49156/places', 
            'lastModified':'2014-11-27T21:42:49Z'
        }, 
        {
            'rel':'place',
            'href':'http://somesite.com:49156/places/2345',
            'lastModified':'2014-11-27T21:42:49Z'
        }
    ]
}

Given that this data is bound to a Map, we can write assertions based around calling the get method of the Map etc.
For example, if I wanted to assert the href of the 'self' link was 'http://somesite.com:49156/places', I would have to:

• Call .get("links") on the response body Map, and cast it to a List<Map>
• Loop through the resultant List, and for each entry (which is a Map), call .get("rel") and check whether it's value is "self"
• Once I have the correct Map (ie. the 'self' link), I would then call .get("href") and assert its value against what I expect it to be

Phew! Messy, fragile, yucky code! It is bad on so many levels!

So, I'm now looking to see if spel can help me.
I still like the idea of binding the json response to a nice generic Map as we have lots of different end points we will be testing against where the response object graph can be quite complex - all in all we would end up with lots and lots of pojo's.
Whilst it would be very convenient for the tests to simply call getters and other such helper methods, it just seems unnecessary to have to create lots and lots of classes.
So binding to a Map is easy because it involves no work :) But how to test it ...

If this were XML (which its not), we could write an xpath query along the lines of:

//links/link[rel='self']/href

So I'd like to try to do something similar with spel if I can.

• The expression [links] will return me the List of Maps
• the expression [links][0] will get the first entry in the List
• and the expression [links][0][href] will get me the entry from the first Map whose key is 'href'

But I need to be able to effectively replace the [0] part of the expression with something that says 'get me the one whose 'rel' entry has the value 'self' - I basically want to use spel as a query language.

Does anyone know if this is possible?

Thanks, Nathan

PS. As this is a Spring project, I already know about MockMvc and JsonPath. MockMvc is not right in this case as these tests are full end to end, so no need to mock anything. Re: JsonPath, the tech lead on this project has a pretty major disliking for it, so I've been asked to investigate alternatives :(