是否有任何工具或库可用于创建模拟数据以在控制器和测试中使用？

The scenario is that there are client apps, the middleware that I will develop with Spring Boot and the backend. When the client app need data, it requests the middleware for it. When the middleware receives the client request, it requests the backend to get related data. Then, it returns the response to the client based on the response it takes from the backend.The scenario is that there are client apps, the