In the REST API, process variables are represented by JSON objects of the followingform:

  1. {
  2.   "type": "String",
  3.   "value": "Some value",
  4.   "valueInfo": {}
  6. }

The REST API supports the Value Types supported by the process engine.

Capitalization of Type Names

In the REST API, the type names start with a capital letter, i.e., String instead of string.

Serialized and Deserialized Object Values

Object Values are instances of (non primitive) Java types. When working with the REST API, it isgenerally advisable to work with the serialized value of a variable. In that case the value isretrieved from the database and directly returned in the http response. If the client you arebuilding is not a Java Applications by itself, make sure you use a text-basedserialization dataformat (such as XML or JSON).

To retrieve the serialized form of a variable, use the deserializeValues=false GET parameter.

原文: https://docs.camunda.org/manual/7.9/reference/rest/overview/variables/