Dojo, JSON, Xstream and FLEXJSON

I’ve been trying to use XStream to generate JSON to be consumed by Dojo. But I can’t find the way to generate the right JSON from XStream, it keeps adding extraneous {} around. I even tried this but no luck . For example I want to generate this JSON output (taken from Dojo FilteringSelect example) :

{identifier:"abbreviation",
items: [
	{name:"Alaska", label:"Alaska",abbreviation:"AK"},
	{name:"Wyoming", label:"Wyoming",abbreviation:"WY"}
]}

My attempt usign XStream:

package com.rubenlaguna.json;

import java.util.ArrayList;
import java.util.Collection;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;

class ItemCollection {
	public String identifier;
	public Collection<Item> items = new ArrayList<Item>();

	public ItemCollection(String identifier) {
		this.identifier = identifier;
	}

	public boolean add(Item arg0) {
		return items.add(arg0);
	}

}

class Item {
	public String name;
	public String label;
	public String abbreviation;

	public Item(String name, String label, String abbreviation) {
		this.name = name;
		this.label = label;
		this.abbreviation = abbreviation;
	}

}

public class WriteXStreamDojoTest {

	public static void main(String[] args) {
		ItemCollection itemCollection = new ItemCollection("abbreviation");
		itemCollection.add(new Item("Alaska","Alaska","AK"));
		itemCollection.add(new Item("Wyoming","Wyoming","WY"));
		
		XStream xstream = new XStream(new JettisonMappedXmlDriver());
		String erroneousJsonStr = xstream.toXML(itemCollection);
		System.out.println(erroneousJsonStr);

	}

}

resulted in the following JSON Output (i added some space and breaklines for readability):

{"com.rubenlaguna.json.ItemCollection":
       {"identifier":"abbreviation",
         "items":{ "@class":"list",
                      "com.rubenlaguna.json.Item":[  
                         {"name":"Alaska","label":"Alaska","abbreviation":"AK"},
                         {"name":"Wyoming","label":"Wyoming","abbreviation":"WY"}
                       ]
                   }
      }
}

I couldn’t figure out how to get XStream to output the desired JSON. The main issue is that I couldn’t make “items” a simple JSON array, it always end up as an object with an array in it. So I decided to give out a try to FLEXJSON. I really found much easier to control the output with this tool. I guess that XStream is more focused on serialization/deserialization and doesn’t allow customization without relaying in custom converters (I didn’t walk that road, too much work). Here is the example source code (also as a gist) using FLEXJSON:

package com.rubenlaguna.json.flexjson;

import flexjson.JSONSerializer;

public class WriteFlexjsonDojoTest {

	public static void main(String[] args) {
		ItemCollection itemCollection = new ItemCollection("abbreviation");
		itemCollection.add(new Item("Alaska", "Alaska", "AK"));
		itemCollection.add(new Item("Wyoming", "Wyoming", "WY"));

		JSONSerializer serializer = new JSONSerializer().include("items").exclude("*.class");
		String correctJsonStr = serializer.serialize(itemCollection);
		System.out.println(correctJsonStr);

	}

}

that yields the following correct result:

{"identifier":"abbreviation",
  "items":[ {"name":"Alaska","label":"Alaska","abbreviation":"AK"},
              {"name":"Wyoming","label":"Wyoming","abbreviation":"WY"}
            ]}