您可以尝试这个来检查prop2是数组还是空字符串

JsonObject jsonObject = new Gson().fromJson("{ \"status\":\"success\", \"payload\": { \"prop1\": 1234, \"prop2\": \"\" } }", JsonObject.class);

JsonObject payload = jsonObject.getAsJsonObject("payload");

JsonElement jsonElement = payload.get("prop2");

if (jsonElement.isJsonArray()) {

// value of prop2 is an array

} else if (jsonElement.isJsonPrimitive()) {

JsonPrimitive jsonPrimitive = jsonElement.getAsJsonPrimitive();

if (jsonPrimitive.isString() && "".equals(jsonPrimitive.getAsString())) {

// value of prop2 is an empty String

}

}