ANT - build時出現 [javac] Compliance level '1.4' is incompatible with target level '1.8'. A compliance level '1.8' or better is required

參考：
http://stackoverflow.com/questions/1487978/setting-the-target-version-of-java-in-ant-javac

今天使用ant的時候出現了奇怪的錯誤：
  [javac] Compliance level '1.4' is incompatible with target level '1.8'. A compliance level '1.8' or better is required

我明明在javac中標明了target="1.8"如下：

  ...

後來找到上述討論區才知道原來可以加入以下這樣的property來解決這樣的問題：