Better scala implementation for determining major java version

Author: cl4es

core/src/test/scala/org/apache/spark/util/UtilsSuite.scala

@@ -784,8 +784,10 @@ class UtilsSuite extends SparkFunSuite with ResetSystemProperties with Logging {
         signal(pid, "SIGKILL")
       }
 
-      val v: String = System.getProperty("java.version")
-      if (v >= "1.8.0") {
+      val versionParts = System.getProperty("java.version").split("[+.\\-]+", 3)
+      var majorVersion = versionParts(0).toInt
+      if (majorVersion == 1) majorVersion = versionParts(1).toInt
+      if (majorVersion >= 8) {
         // Java8 added a way to forcibly terminate a process. We'll make sure that works by
         // creating a very misbehaving process. It ignores SIGTERM and has been SIGSTOPed. On
         // older versions of java, this will *not* terminate.

project/SparkBuild.scala

@@ -167,8 +167,10 @@ object SparkBuild extends PomBuild {
     publishLocalBoth <<= Seq(publishLocal in MavenCompile, publishLocal).dependOn,
 
     javacOptions in (Compile, doc) ++= {
-      val version = System.getProperty("java.version")
-      if (version >= "1.8.0") Seq("-Xdoclint:all", "-Xdoclint:-missing") else Seq.empty
+      val versionParts = System.getProperty("java.version").split("[+.\\-]+", 3)
+      var major = versionParts(0).toInt
+      if (major == 1) major = versionParts(1).toInt
+      if (major >= 8) Seq("-Xdoclint:all", "-Xdoclint:-missing") else Seq.empty
     },
 
     javacJVMVersion := "1.7",