Install devtool:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
Even we install devtool, in Intellij, it won'g automacitlly recompile when we change something, to enable this, modify setting:
Enable "Build project automaticlly".
Then open "Registry":
Enable "compiler.automake.allow.when.app.running"