* What went wrong:
A problem occurred configuring root project 'spring'.
> Could not resolve all files for configuration ':classpath'.
   > Could not resolve org.jetbrains.dokka:integration:0.9.15.
     Required by:
         project : > org.jetbrains.dokka:dokka-gradle-plugin:0.9.15
      > Could not resolve org.jetbrains.dokka:integration:0.9.15.
         > Could not get resource 'https://repo.spring.io/plugins-release/org/jetbrains/dokka/integration/0.9.15/integration-0.9.15.pom'.
            > Could not GET 'https://repo.spring.io/plugins-release/org/jetbrains/dokka/integration/0.9.15/integration-0.9.15.pom'. Received status code 401 from server: Unauthorized

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

* Get more help at https://help.gradle.org

解决办法：

打开spring中的build.gradle文件，改成0.9.17