From 33ddd2e3fa56212f48c748dee7751eeafe6763f0 Mon Sep 17 00:00:00 2001
From: Joshi <rekhajoshm@gmail.com>
Date: Wed, 1 Jul 2015 19:58:41 -0700
Subject: [PATCH] update checkInputColumn to print more info if needed

---
 .../main/scala/org/apache/spark/ml/util/SchemaUtils.scala  | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/mllib/src/main/scala/org/apache/spark/ml/util/SchemaUtils.scala b/mllib/src/main/scala/org/apache/spark/ml/util/SchemaUtils.scala
index 9252618715625..a5f3e14dac696 100644
--- a/mllib/src/main/scala/org/apache/spark/ml/util/SchemaUtils.scala
+++ b/mllib/src/main/scala/org/apache/spark/ml/util/SchemaUtils.scala
@@ -34,11 +34,14 @@ object SchemaUtils {
    * @param colName  column name
    * @param dataType  required column data type
    */
-  def checkColumnType(schema: StructType, colName: String, dataType: DataType,
+  def checkColumnType(schema: StructType,
+                      colName: String,
+                      dataType: DataType,
                       msg: String = ""): Unit = {
     val actualDataType = schema(colName).dataType
+    val message = if (msg != null && msg.trim.length > 0) " " + msg else ""
     require(actualDataType.equals(dataType),
-      s"Column $colName must be of type $dataType but was actually $actualDataType.$msg")
+      s"Column $colName must be of type $dataType but was actually $actualDataType.$message")
   }
 
   /**