Refactor

apache · Dec 10, 2018 · b68e7b1 · b68e7b1
1 parent 987fa18
commit b68e7b1
Showing 1 changed file with 6 additions and 13 deletions.
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveShim.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveShim.scala
@@ -53,19 +53,12 @@ private[hive] object HiveShim {
    * This function in hive-0.13 become private, but we have to do this to work around hive bug
    */
   private def appendReadColumnNames(conf: Configuration, cols: Seq[String]) {
-    val old: String = conf.get(ColumnProjectionUtils.READ_COLUMN_NAMES_CONF_STR, "")
-    val result: StringBuilder = new StringBuilder(old)
-    var first: Boolean = old.isEmpty
-
-    for (col <- cols) {
-      if (first) {
-        first = false
-      } else {
-        result.append(',')
-      }
-      result.append(col)
-    }
-    conf.set(ColumnProjectionUtils.READ_COLUMN_NAMES_CONF_STR, result.toString)
+    val key = ColumnProjectionUtils.READ_COLUMN_NAMES_CONF_STR
+    val value = Option(conf.get(key, null))
+      .map(old => cols.+:(old))
+      .getOrElse(cols)
+      .mkString(",")
+    conf.set(key, value)
   }
 
   /*