问找不到Spring Boot模块错误

EN

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
</parent>

module com.journaldev.spring.SpringWebflux {
    requires reactor.core;
    requires spring.web;
    requires spring.context;
    requires spring.webflux;
    requires spring.boot;
    requires spring.boot.autoconfigure;
}

module-info.java:[2,21] module not found: reactor.core
module-info.java:[3,20] module not found: spring.web
module-info.java:[4,20] module not found: spring.context
module-info.java:[5,20] module not found: spring.webflux
module-info.java:[6,20] module not found: spring.boot
module-info.java:[7,25] module not found: spring.boot.autoconfigure