1) “File” -> “Settings” -> “Build,Execution,Deplyment” -> “Compiler”,选中打勾 “Build project automatically” 。
2) 组合键:“Shift+Ctrl+Alt+/” ,选择 “Registry” ,选中打勾 “compiler.automake.allow.when.app.running”
如果还是不行的话就加上如下maven配置
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>