A cycle was detected in the build path of project:

解決Eclipse中Java工程間循環引用而報錯的問題
如果我們的項目包含多個工程（project），而它們之間又是循環引用的關係，那麼Eclipse在編譯時會拋出如下一個錯誤信息：
“A cycle was detected in the build path of project: XXX”
解決方法非常簡單：
Eclipse Menu -> Window -> Preferences... -> Java -> Compiler -> Building -> Building path problems -> Circular dependencies -> 將Error改成Warning。