KNOX-2189 - KnoxShellTable.select() must handle whitespace (#256)

diff --git a/gateway-shell/src/main/java/org/apache/knox/gateway/shell/table/KnoxShellTable.java b/gateway-shell/src/main/java/org/apache/knox/gateway/shell/table/KnoxShellTable.java
index 15d403c..47439d4 100644
--- a/gateway-shell/src/main/java/org/apache/knox/gateway/shell/table/KnoxShellTable.java
+++ b/gateway-shell/src/main/java/org/apache/knox/gateway/shell/table/KnoxShellTable.java
@@ -356,7 +356,8 @@
   public KnoxShellTable select(String cols) {
     KnoxShellTable table = new KnoxShellTable();
     List<List<Comparable<? extends Object>>> columns = new ArrayList<>();
-    String[] colnames = cols.split(",");
+    cols = cols.trim();
+    String[] colnames = cols.split("\\s*,\\s*");
     for (String colName : colnames) {
       table.header(colName);
       columns.add(values(headers.indexOf(colName)));
diff --git a/gateway-shell/src/test/java/org/apache/knox/gateway/shell/table/KnoxShellTableTest.java b/gateway-shell/src/test/java/org/apache/knox/gateway/shell/table/KnoxShellTableTest.java
index cde34f9..e65278a 100644
--- a/gateway-shell/src/test/java/org/apache/knox/gateway/shell/table/KnoxShellTableTest.java
+++ b/gateway-shell/src/test/java/org/apache/knox/gateway/shell/table/KnoxShellTableTest.java
@@ -121,11 +121,6 @@
         + "|    123     |    456     |  344444444   |\n"
         + "|    789     |    012     |  844444444   |\n" + "+------------+------------+--------------+\n";
 
-    String expectedResult2 = "+------------+--------------+\n"
-        + "|  Column A  |   Column C   |\n" + "+------------+--------------+\n"
-        + "|    123     |  344444444   |\n"
-        + "|    789     |  844444444   |\n" + "+------------+--------------+\n";
-
     KnoxShellTable table = new KnoxShellTable();
 
     table.header("Column A").header("Column B").header("Column C");
@@ -135,8 +130,8 @@
 
     assertEquals(expectedResult, table.toString());
 
-    table = table.select("Column A,Column C");
-    assertEquals(expectedResult2, table.toString());
+    table = table.select(" Column A   ,   Column B ,  Column C  ");
+    assertEquals(expectedResult, table.toString());
   }
 
   @Test