How to query a file-based JSON datasource

We'll use a sample of a single record, like:

{ "item" : [{ "value" : 895, "text" : "test" }] }

Resolution:

1. In the "JSON file" field you must browse locally or via shares to a text file containing your json data. 

2. Choose "Use the report JSON Expression when filling the report" to be able to specify your query within the individual report.

3. In iReport's "report query", choose json in the drop-down.  For our sample, try a query like:

   <queryString language="json">
       <![CDATA[item]]>
   </queryString>
   

4. Next you need to manually create fields, matching the names of our json data, then treat this like any other report source:

   <field name="value" class="java.lang.Integer">
       <fieldDescription>
           <![CDATA[value]]>
       </fieldDescription>
   </field>
   <field name="text" class="java.lang.String">
       <fieldDescription>
           <![CDATA[text]]>
       </fieldDescription>
   </field>
   

As for query syntax, currently we only support only simple (single) filtering criteria with these operators: <, <=, >, >=, == and !=.

An example query with an operator to return only the line we've specified via an Input Control might be :

<queryString language="json">
    <![CDATA[item(value == $P{myValueInput})]]>
</queryString>

Ref. Case #00033486

ejemplojson.json