0. clone
git clone https://github.com/apereo/cas-overlay-template.git
1. down gradle
Directory: C:\Users\xiaobin\.gradle\wrapper\dists\gradle-4.10.2-bin
$cd cas-overlay-template
$gradlew.bat
copy gradle-4.10.2-bin.zip to "Directory" below the random folder。
Ctrl+c
remove other files.
2. build war
$gradlew build