------Error handling mechanism------
Default effect
1 returns a default error page
The client responds with json data by default
Principle: Refer to ErrorMvcAutoConfiguration Error automatic configuration
DefaultErrorAttributes
BasicErrorController
ErrorPageCustomizer
DefaultErrorViewResolver
step:
Once the system has an error: ErrorPageCustomizer takes effect (custom error response rules)
2 How to customize error responses
1) Customize the error page
2) Customize json error data