Although there are already tons of existing Java JSON libraries, I needed one which would:
-
be minimalistic
- no reflection of any sort, no validation, no schema, no custom POJO field/class support
- no external dependency
- easily pluggable in other projects: one single source file
-
be performant
-
have a nice and handy API with specialized getters and setters
-
avoid any kind of abstraction other than Serializable around values, without any wrapping
-
use a common parent Serializable interface for JSON objects and arrays
The com.republicate.json.Json interface extends Serializable and is implemented by its two inner classes Json.Array and Json.Object.
Json.Array extends List<Serializable> and Json.Object extends Map<String, Serializable>.
Using Maven:
<dependency>
<groupId>com.republicate</groupId>
<artifactId>essential-json</artifactId>
<version>2.5</version>
</dependency>
Using Gradle:
implementation 'com.republicate:essential-json:2.3'
The generic Json.parse(string_or_reader) method will return a com.republicate.Json value containing a Json.Object or Json.Array object.
If you want to parse a content without knowing if it's a JSON container or a simple JSON value,
you will call the Json.parseValue(string_or_reader) method to get a Serializable.
import com.republicate.json.Json;
...
Json container = Json.parse(string_or_reader);
// container will be a JSON object or a JSON array
if (container.isObject())
{
Json.Object obj = container.asObject();
...
}
Serializable value = Json.parseValue(string_or_reader);
// value will either be a JSON container or a single Serializable value
Containers toString() and toString(Writer) methods will render JSON strings with proper quoting and encoding.
import com.republicate.json.Json;
...
// getting a String
String json = container.toString();
// rendering towards a Writer
container.toString(writer);
Json.Array and Json.Object constructors (or equivalents Json.newArray() and Json.newObject() helper methods) can respectively be given an existing Iterable or an existing Map ; both can also be given a JSON string.
Both containers have specialized getters (getString, getBoolean, etc.).
Json.Array has helper methods push, pushAll and put that return self (and rely on the standard add, addAll and set ArrayList methods).
Json.Object has helper methods set and setAll that return self (and rely on the standard put and putAll Map methods).
import com.republicate.json.Json;
...
Json.Array arr = Json.newArray("[1,2,3]").add(4).add(5);
Json.Object obj = new Json.Object(some_existing_map).set("foo", "bar").set(("baz", arr);
The two reentrant methods Json.toJson(java.lang.Object) and Json.toSerializable(java.lang.Object) will try hard to convert any standard Java container to a JSON structure.