Java object model specification and Object Model Specification

Java object model specification and Object Model Specification
The following is a set of object model (entity model)-vo (Object model that interacts with the front-end) that I have summarized based on my work experience, frontend refers to pages, mobile terminals, and remote service calls.)-xxxReq (the entity corresponding to the json request sent by the frontend)-xxxResp (the entity corresponding to the response json returned to the frontend) -po (Object Model for interaction with persistence layer, persistence layer refers to relational database, NoSQL, search engine, etc.)-xxx represents a specific business object, such: simple Object models such as UserReq, UserResp, and User are easier to understand and use than complicated vo, bo, dto, And po models, and the conversion between them is also concise and straightforward (vo <-> po)