HTTP Status 400 encountered in the process of learning SpringMVC - Bad Request error, record it for future traceability encountered similar problems.
Question one:
The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).
wrong description:
Translated:服务器无法或将不会处理请求，因为某些东西被认为是客户端错误（例如，错误的请求语法、无效的请求消息帧或欺骗的请求路由）。problem causes:
The time of filing data in a form, field data inconsistency if the field data type and forms the rear end of the page request type, such as id attribute of the User class, the entity class type Integer, String submitted data written in the type of form, will cause such problems.
Solution:
Form submission data type checking whether there are inconsistencies and background requirements, generally such causes.
