I was really killed by this problem today. Out of self-confidence, I fell into the pit.
Today I wrote an integration of ActiveMQ and SpringBoot. After writing it, I want to test it with POSTMAN, directly test the interface, and find that there is no response at all, and the code background does not report an error. The information prompted by POSTMAN is that the connection is not successful, and it is a wrong link. (Could not get any response).
It took a long time to troubleshoot the problem, such as whether the startup class is configured properly, whether the startup class of the Controller that needs to be accessed is under the same package, whether the scan is normal, and so on. In the end it was not resolved successfully.
Then I still didn't give up, so I tried it with a browser, and then the following error message appeared:
