Camel - HTTP request content based redirecting

I 'm trying to use camel for redirecting an http request based on the contents of the request body.

I 've created an endpoint for receiving http requests and I 'm able to successfully redirect my request to a different URL, using the following route;

<route>
    <from uri="servlet:myapptest2?matchOnUriPrefix=true"/>  
    <to uri="http://sampleurl/test?bridgeEndpoint=true&amp;throwExceptionOnFailure=false" />
</route>

But I 'm not able to figure out a way to check the http request body. My HTTP request will be having a JSON body similar to this;

{
    "testLoginRequest": {
            "sampleData1": [{
                    "key1": "val1",
                    "key2": "val2"          
            }],
            "sampleData2": [{
                    "key1": "val1",
                    "key2": "val2"
            }]
    }
}

I want to redirect the request to a specific URL if the JSON contains the value "testLoginRequest". I read that this should be possible like ;

from("direct:test"). 
    choice().
    when(body().contains("javainuse1"))
    .to("jms:queue:javainuse1").       
    otherwise().
    to("jms:queue:otherwise");

Since I have to use the XML DSL, I tried implementing the following route, but it doesn't seem to work;

<route>
    <from uri="servlet:myapptest3?matchOnUriPrefix=true" /> 
    <choice>
        <when>
            <simple>${body} contains 'testLoginRequest' </simple>
            <to uri="http://sampleurlforlogin/test?bridgeEndpoint=true&amp;throwExceptionOnFailure=false" />
        </when>                         
    </choice>
</route>

Am I following the right approach. What am I doing wrong here?