Siena JSON support

UNDER RE-CONSTRUCTION... Will evolve soon!
New manuals page also available on Siena Github Wiki

Siena comes with a JSON implementation. This implementation is contained in a sigle class: siena.Json. A Json object wraps any kind of JSON structure. This is, a Json object can contain a boolean value, a String, a Map, a List, a number or null. You can know wich type of object is wrapped using its isXXX() methods: isString(), isNumber(), isBoolean(), isMap(), isList() or isNull().

If you like the siena's JSON implementation you can use it individually. If you want to persist complex data structures into a database using siena you can use Json objects directly in your persistent classes. Siena will care about serializating and deserializating the object into Strings.

To start using siena.Json the best is to import the class and all its members:

import siena.Json;
import static siena.Json.*;

Basic usage

Create a map:

Json json = map().put("key1", 1234)
	.put("key2", true)
	.put("key3", null)
	.put("key4", "foo");
System.out.println(json);

The output:

{"key1": 1234, "key2": true, "key3": null, "key4": "foo"}

Retrieving data from previous map:

int value1 = json.get("key1").asInt();

You have several asXXX() methods.

Create a list:

Json json = list("foo", "bar", "baz", true, false, null, 1234);

The output:

["foo", "bar", "baz", true, false, null, 1234]

Retrieving data from previous list:

int size = json.size();
boolean b = json.at(3).bool();

Complex example:

Json json = list("foo", "bar", "baz",
	map().put("key1", true)
		.put("key2", false)
		.put("key3", list(1, 2, 3, 4)));
System.out.println(json);

The output:

["foo", "bar", "baz", {"key1": true, "key2": false, "key3": [1, 2, 3, 4]}]

Loading data

Json json = loads("[true, false, null, {}]");
System.out.println(json);

The output:

[true, false, null, {}]

Converting from arrays and collections

The buit-in siena JSON implementaiton lets you create Json objects from plain Java arrays or collections. The Json constructor accepts arrays, collections and maps. Examples:

Json fromArray = new Json(new Object[]{1, 2, 3});

Json fromCollection = new Json(Arrays.asList(new Object[]{1, 2, 3}));

Map<String, Object> m = new HashMap<String, Object>();
m.put("foo", 1);
Json fromMap = new Json(m);

siena project