Startup class error (IllegalStateException) :
A:
Cause: The corresponding SpringBoot project startup class was not found during unit test startup
Solution:
No classes are defined in the SpringBoot project and the boot classes are not described using the @SpringBootApplication annotation
The unit test class is not in the package or subpackage in which the starter class resides
2:
Reason: There may be multiple boot classes in the Sprigboot project…
Solution:
Mybatis error:
A:
Reason: access property or call property is NULL
Solution:
Check if the test class is managed by the Spring container, has the @SpringBoottest annotation, or is under the test package
Check if the property is dependent injected by Spring (add @Autowired annotation)
Is the @Test annotation introduced correctly on the unit Test method
Reason: Usually the object does not exist
Solution: Run it first. If there is no problem in running it, it is a tool (IDEA) problem, which does not affect the operation of the program. Otherwise, add @Mapper annotation in the Mapper layer
SpringWeb error:
404 (request page does not exist)
Cause: The service did not start, the port is not correct
Check if the requested URL is correct.
Check whether the requested resource is managed by Spring,
Check that the port is correct
The server encountered an error and could not complete the request.
The reason:
Server error, etc.
Solution: Restart the server, etc…
Three: 400 (server does not understand the syntax of the request)
Reason: When the client submitted the number of request parameters, type. A format mismatch is a 404
Solution: check the type, number, such as the date of submission to the server
Four: 405 (Disable the method specified in the request)
Reason: The client commits in a way that does not match the handler defined by the server
Solution: Check the way the request is handled, such that the service can only be handled with GET requests, not POST requests
