无法调用"com.google.gson.JsonElement.isJsonNull()“，因为"com.google.gson.JsonObject.get(String)”的返回值为空

import com.google.gson.JsonElement;
import com.google.gson.JsonObject;

public class JsonParsingExample {
    public static void main(String[] args) {
        String jsonString = "{\"name\": \"John\", \"age\": 30}";

        JsonObject jsonObject = new Gson().fromJson(jsonString, JsonObject.class);

        if (jsonObject.has("name")) {
            JsonElement nameElement = jsonObject.get("name");
            if (!nameElement.isJsonNull()) {
                String name = nameElement.getAsString();
                System.out.println("Name: " + name);
            } else {
                System.out.println("Name is null");
            }
        } else {
            System.out.println("Name key not found in JSON");
        }
    }
}