How do I parse this escaped Json with Gson java?
What you have here
"parameters": "{\"firstName\":\"someName\",\"lastName\":\"someLastName\"}",
is a JSON pair where both the name (which is always a JSON string) and the value are JSON strings. The value is a String that can be interpreted as a JSON object. So do just that
String jsonString = data.getAsJsonObject().get("parameters").getAsJsonPrimitive().getAsString();
JsonObject parameters = gson.fromJson(jsonString, JsonObject.class);
The following
Gson gson = new Gson();
JsonElement data = gson
.fromJson(" {\n" + " \"message\": \"someName someLastName has sent you a question\",\n"
+ " \"parameters\": \"{\\\"firstName\\\":\\\"someName\\\",\\\"lastName\\\":\\\"someLastName\\\"}\",\n"
+ " \"id\": 141\n" + " }", JsonElement.class);
String jsonString = data.getAsJsonObject().get("parameters").getAsJsonPrimitive().getAsString();
JsonObject parameters = gson.fromJson(jsonString, JsonObject.class);
System.out.println(parameters);
prints the JSON text representation of that JsonObject
{"firstName":"someName","lastName":"someLastName"}