SPARK-2804: Remove scalalogging-slf4j dependency

This also Closes #1701.

Author: GuoQiang Li <witgo@qq.com>

Closes #1208 from witgo/SPARK-1470 and squashes the following commits:

422646b [GuoQiang Li] Remove scalalogging-slf4j dependency

1 files changed, 7 insertions, 3 deletions

diff --git a/core/src/main/scala/org/apache/spark/Logging.scala b/core/src/main/scala/org/apache/spark/Logging.scala
index 807ef3e9c9..d4f2624061 100644
--- a/core/src/main/scala/org/apache/spark/Logging.scala
+++ b/core/src/main/scala/org/apache/spark/Logging.scala
@@ -39,13 +39,17 @@ trait Logging {
   // be serialized and used on another machine
   @transient private var log_ : Logger = null
 
+  // Method to get the logger name for this object
+  protected def logName = {
+    // Ignore trailing $'s in the class names for Scala objects
+    this.getClass.getName.stripSuffix("$")
+  }
+
   // Method to get or create the logger for this object
   protected def log: Logger = {
     if (log_ == null) {
       initializeIfNecessary()
-      var className = this.getClass.getName
-      // Ignore trailing $'s in the class names for Scala objects
-      log_ = LoggerFactory.getLogger(className.stripSuffix("$"))
+      log_ = LoggerFactory.getLogger(logName)
     }
     log_
   }