Spark 2.1.0 contains com.fasterxml.jackson.core as transitive dependency. So, we do not need to include then in libraryDependencies.
But if you want to add a different com.fasterxml.jackson.core dependencies’ version then you have to override them. Like this:
name := "testSpark2"
version := "1.0"
scalaVersion := "2.11.8"
dependencyOverrides += "com.fasterxml.jackson.core" % "jackson-core" % "2.8.7"
dependencyOverrides += "com.fasterxml.jackson.core" % "jackson-databind" % "2.8.7"
dependencyOverrides += "com.fasterxml.jackson.module" % "jackson-module-scala_2.11" % "2.8.7"
libraryDependencies += "org.apache.spark" % "spark-core_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-mllib_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-repl_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-streaming-flume_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-sql_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-network-shuffle_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-streaming-kafka-0-10_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-hive_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-streaming-flume-assembly_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-mesos_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-graphx_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-catalyst_2.11" % "2.1.0"
libraryDependencies += "org.apache.spark" % "spark-launcher_2.11" % "2.1.0"
So, change your build.sbt like the one above and it will work as expected.
I hope it helps!