spring boot configuration annotation processor not found in classpath

最近跟着教程做 Spring boot 的开发出现了这个错误:

spring boot configuration annotation processor not found in classpath

错误提示

打开在线文档后，把依赖拷进 build 也无济于事，

dependencies {
    optional "org.springframework.boot:spring-boot-configuration-processor"
}

compileJava.dependsOn(processResources)

最后把依赖里的 optional "org.springframework.boot:spring-boot-configuration-processor" 改成 compile("org.springframework.boot:spring-boot-configuration-processor") 就好了