【Question】

I have a problem very similar to
http://community.jaspersoft.com/questions/844023/need-help-looping-throu…,

But I can’t just change the JSON file as done by the person asking that question.
Any help would be greatly appreciated.

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I am trying to create a report in iReport Designer v5.6.0 that loops through a JSON file and returns all data from different levels. For example, I’ve built a very simple JSON file that has a list of customers, and for each customer it lists all of his/her vehicles including fields for make, model and mileage. The desired output would be a list of customers and underneath each customer a list of the vehicles he/she owns.

I have built a template that correctly displays each customer name, but I have been unable to figure out how to loop through each customer’s vehicles. (I can return the first vehicle by adding [0] to the field, but I can’t figure out how to loop through all vehicles).

JSON data:

[{“custName”: “Alison Anderson”,“custCars”:[{“carMake”: “Chevrolet”,“carModel”: “Avalanche”,“carMiles”: 97740},{“carMake”: “Chevrolet”,“carModel”: “Beretta”,“carMiles”: 165500}]},{“custName”: “Bart Bloomfield”,“custCars”:[{“carMake”: “Ford”,“carModel”: “F150”,“carMiles”: 43252},{“carMake”: “Mercury”,“carModel”: “Marauder”,“carMiles”: 26699}]},{“custName”: “Charles Cominsky”,“custCars”:[{“carMake”: “Porsche”,“carModel”: “Cayman”,“carMiles”: 15520}]}]

【Answer】

It’s more convenient to convert the multilevel JSON data to a two-dimensional table if we can prepare the JSON data into the desired format in an independent computing tool. Here I prepare it with esProc. esProc is such a tool driven by Structured Process Language (SPL). Below is the SPL script:

A1: Read in the JSON data as a text file and then into a table sequence. Here A1 is equivalent to a target result table grouped by custName field.

A2: Based on A1’s table sequence, news() function parses values under custCars field to form a new table sequence and joins each record after A1’s custName.