Failed to initialize compiler: object scala.runtime in compiler mirror not found.
** Note that as of 2.8 scala does not assume use of the java classpath.
** For the old behavior pass -usejavacp to scala, or if using a Setting
** object programatically, settings.usejavacp.value = true.
网上有两种解决办法
1. -Dscala.usejavacp=true 但我看spark-shell中已经有
2.是说jar问题引起。
http://blog.csdn.net/hiplayer/article/details/51042407
才发现是引入的jar有问题，用浏览器下载的。看是显示成功，实际是失败的。有些jar打开里面没东西。深坑莫入。