idea for possible reasons for the failure of SpringBoot hot deployment

Add in the pom.xml file

<! - Thermal deployment configuration: after the restart is not required to modify the code works -> 
<dependency> 
    <the groupId> org.springframework.boot </ the groupId> 
    <the artifactId> Boot-Spring-DevTools </ the artifactId> 
</ dependency>

After completion of the IDEA modified code may still need to restart the project to take effect, the reasons for this may be the IDEA does not automatically compiled by default, you need to

IDEA automatically compiled set, as follows

Select File-> Setting-> Compiler, check the

 

 Then press ctrl + shift + alt + /,

Select the first, find the following, and check

After the configuration can be successfully