Cannot resolve org.springframework.bootspring-boot-starter-webunknown

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.wsc</groupId>
    <artifactId>filesystem-manager</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version> 2.3.3.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
            <version> 2.3.3.RELEASE</version>
        </dependency>
    </dependencies>

</project>

出现Cannot resolve org.springframework.bootspring-boot-starter-webunknown此问题是引入的dependency标签里没有引入version标签导致的。一定要有明确的版本号。没有明确的版本号会导致jar包下载失败