我可以直接在Maven中使用GitHub项目吗？

您可以使用 github作为Maven仓库 - 这与直接引用项目并不相同，它有一个pom文件只表示它是Maven项目。

如果项目在中央库或其他仓库中不可用，那么最好的办法可能是克隆它，构建它，然后在本地安装。您应该确认它在其他地方确实无法使用。

I am interested in using a project on GitHub as a dependency in my project. The GitHub project has a pom file. Can I modify my pom file to use this project? If so, how? If not, what is my best course of action?

Not in the way I think you mean, AFAIK.

You can use github as a Maven repository--this is not the same thing as directly referencing a project, and that it has a pom file means only that it's a Maven project.

If the project is not available in the central, or other, repository, your best bet may be to clone it, build it, and install it locally. You should confirm that it's truly not available elsewhere.