What type of field, tokenizer, and request should Solr use to find the JSON storage field?

I am working with the Solr index (v1.4.1), which has a field that stores serialized JSON. The following is an example of JSON stored in the "json" field in a document in Solr .

{
    "uri": "http://localhost/individual/n503",
    "name": "Smith, Richard",
    "title": "Programming CIO",
    "items": [{
        "uri": "http://localhost/individual/n1873",
        "type": "http://localhost/individual/book"
    }]
}

I would like to request this serialized JSON field for the existence of a URI (e.g., http://localhost/individual/n1873). I am using Scala with SolrJ (v1.4.1) to query for results. The function is as follows:

def documentsForUri(uri: String) = {
  var query = new SolrQuery();
  query.setQuery( "json:" + uri )
  var rsp = solr.query( query )
  rsp.getResults()
}

Passing uri = "http://localhost/individual/n1873"to the function, we get 0 documents. I tried changing the ":" to "\:", and that didn't seem to help. In my schema.xml, I tried to define the field as solr.StrFieldand solr.TextField. For instance:

<types>
...
  <fieldType name="text" class="solr.StrField" sortMissingLast="true" omitNorms="true"/>
  <fieldType name="text_ws" class="solr.TextField" positionIncrementGap="100"/>
...
</types>
<solrQueryParser defaultOperator="OR"/>

, , :

<fields>
...
  <field name="json" type="text" indexed="true" stored="true" multiValued="false" required="false"/>
...
</fields>

:

<fields>
...
  <field name="json" type="text_ws" indexed="true" stored="true" multiValued="false" required="false"/>
...
</fields>

uri ( "\" ) uri ( ":" ).

, ? "" SQL- , JSON .