[SPARK-17263][SQL] Add hexadecimal literal parsing

## What changes were proposed in this pull request?
This PR adds the ability to parse SQL (hexadecimal) binary literals (AKA bit strings). It follows the following syntax `X'[Hexadecimal Characters]+'`, for example: `X'01AB'` would create a binary the following binary array `0x01AB`.

If an uneven number of hexadecimal characters is passed, then the upper 4 bits of the initial byte are kept empty, and the lower 4 bits are filled using the first character. For example `X'1C7'` would create the following binary array `0x01C7`.

Binary data (Array[Byte]) does not have a proper `hashCode` and `equals` functions. This meant that comparing `Literal`s containing binary data was a pain. I have updated Literal.hashCode and Literal.equals to deal properly with binary data.

## How was this patch tested?
Added tests to the `ExpressionParserSuite`, `SQLQueryTestSuite` and `ExpressionSQLBuilderSuite`.

Author: Herman van Hovell <hvanhovell@databricks.com>

Closes #14832 from hvanhovell/SPARK-17263.

1 files changed, 7 insertions, 6 deletions

diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/ExpressionParserSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/ExpressionParserSuite.scala
index dbc5db39ae..4e399eef1f 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/ExpressionParserSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/ExpressionParserSuite.scala
@@ -331,16 +331,17 @@ class ExpressionParserSuite extends PlanTest {
   test("type constructors") {
     // Dates.
     assertEqual("dAte '2016-03-11'", Literal(Date.valueOf("2016-03-11")))
-    intercept[IllegalArgumentException] {
-      parseExpression("DAtE 'mar 11 2016'")
-    }
+    intercept("DAtE 'mar 11 2016'")
 
     // Timestamps.
     assertEqual("tImEstAmp '2016-03-11 20:54:00.000'",
       Literal(Timestamp.valueOf("2016-03-11 20:54:00.000")))
-    intercept[IllegalArgumentException] {
-      parseExpression("timestamP '2016-33-11 20:54:00.000'")
-    }
+    intercept("timestamP '2016-33-11 20:54:00.000'")
+
+    // Binary.
+    assertEqual("X'A'", Literal(Array(0x0a).map(_.toByte)))
+    assertEqual("x'A10C'", Literal(Array(0xa1, 0x0c).map(_.toByte)))
+    intercept("x'A1OC'")
 
     // Unsupported datatype.
     intercept("GEO '(10,-6)'", "Literals of type 'GEO' are currently not supported.")