JSON

Unlike some other languages, Java does not have first class support for JSON so we provide two classes to make handling JSON in your Vert.x applications a bit easier.

JSON objects

The JsonObject class represents JSON objects.

A JSON object is basically just a map which has string keys and values can be of one of the JSON supported types (string, number, boolean).

JSON objects also support null values.

Creating JSON objects

Empty JSON objects can be created with the default constructor.

You can create a JSON object from a string JSON representation as follows:

String jsonString = "{\"foo\":\"bar\"}";
JsonObject object = new JsonObject(jsonString);

Putting entries into a JSON object

Use the put methods to put values into the JSON object.

The method invocations can be chained because of the fluent API:

JsonObject object = new JsonObject();
object.put("foo", "bar").put("num", 123).put("mybool", true);

Getting values from a JSON object

You get values from a JSON object using the getXXX methods, for example:

String val = jsonObject.getString("some-key");
int intVal = jsonObject.getInteger("some-other-key");

Encoding the JSON object to a String

You use encode to encode the object to a String form.

JSON arrays

The JsonArray class represents JSON arrays.

A JSON array is a sequence of values (string, number, boolean).

JSON arrays can also contain null values.

Creating JSON arrays

Empty JSON arrays can be created with the default constructor.

You can create a JSON array from a string JSON representation as follows:

String jsonString = "[\"foo\",\"bar\"]";
JsonArray array = new JsonArray(jsonString);

Adding entries into a JSON array

You add entries to a JSON array using the add methods.

JsonArray array = new JsonArray();
array.add("foo").add(123).add(false);

Getting values from a JSON array

You get values from a JSON array using the getXXX methods, for example:

String val = array.getString(0);
Integer intVal = array.getInteger(1);
Boolean boolVal = array.getBoolean(2);

Encoding the JSON array to a String

You use encode to encode the array to a String form.