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 usign 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"}
]}
Tags: dojo, flexjson, java, javascript, json, output, serialize, xstream