为了可以用Eclipse编译基于Scala的Spark Project，需要安装sbt
环境：OS X Yosemite 10.10.3
1.安装Xcode
因为要在终端用macports安装sbt，而Xcode是macports安装的前提，所以要先去APPstore下载Xcode，并安装其command line developer tools。
安装比较简单，详见：https://guide.macports.org/#installing
2.安装macports
去官网下载其安装包并安装，和安装QQ一样简单
详见：https://guide.macports.org/#installing
3.安装sbt
在终端下输入一下命令：
port install sbt
看到类似以下信息就算安装完了：
...这里省略很多log...
downloading https://repo.typesafe.com/typesafe/ivy-releases/org.scala-sbt/apply-macro/0.13.7/jars/apply-macro.jar ...
[SUCCESSFUL ] org.scala-sbt#apply-macro;0.13.7!apply-macro.jar (9005ms)
:: retrieving :: org.scala-sbt#boot-app
confs: [default]
51 artifacts copied, 0 already retrieved (15709kB/378ms)
Getting Scala 2.10.4 (for sbt)...
downloading https://repo1.maven.org/maven2/org/scala-lang/jline/2.10.4/jline-2.10.4.jar ...
[SUCCESSFUL ] org.scala-lang#jline;2.10.4!jline.jar (1589ms)
:: retrieving :: org.scala-sbt#boot-scala
confs: [default]
5 artifacts copied, 0 already retrieved (24459kB/195ms)
[info] Set current project to hello (in build file:/Users/apple/Desktop/hello/)
4.跑个hello world
为了验证sbt是不是安装成功，我们跑个hello world试试
$ mkdir hello $ cd hello $ echo 'object Hi { def main(args: Array[String]) = println("Hi!") }' > hw.scala $ sbt ... > run
[info] Updating {file:/Users/apple/Desktop/hello/}hello...
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[info] Done updating.
[info] Compiling 1 Scala source to /Users/apple/Desktop/hello/target/scala-2.10/classes...
[info] Running Hi
Hi!
[success] Total time: 4 s, completed Jul 8, 2015 11:17:46 AM
这是官网的示例，按照他的做并出现相同的结果就对了！
到此，mac下安装sbt就结束了。