[SPARK-16515][SQL] set default record reader and writer for script transformation

## What changes were proposed in this pull request?
In ScriptInputOutputSchema, we read default RecordReader and RecordWriter from conf. Since Spark 2.0 has deleted those config keys from hive conf, we have to set default reader/writer class name by ourselves. Otherwise we will get None for LazySimpleSerde, the data written would not be able to read by script. The test case added worked fine with previous version of Spark, but would fail now.

## How was this patch tested?
added a test case in SQLQuerySuite.

Closes #14169

Author: Daoyuan Wang <daoyuan.wang@intel.com>
Author: Yin Huai <yhuai@databricks.com>

Closes #14249 from yhuai/scriptTransformation.

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkSqlParser.scala

@@ -1325,7 +1325,10 @@ class SparkSqlAstBuilder(conf: SQLConf) extends AstBuilder {
 
     // Decode and input/output format.
     type Format = (Seq[(String, String)], Option[String], Seq[(String, String)], Option[String])
-    def format(fmt: RowFormatContext, configKey: String): Format = fmt match {
+    def format(
+        fmt: RowFormatContext,
+        configKey: String,
+        defaultConfigValue: String): Format = fmt match {
       case c: RowFormatDelimitedContext =>
         // TODO we should use the visitRowFormatDelimited function here. However HiveScriptIOSchema
         // expects a seq of pairs in which the old parsers' token names are used as keys.
@@ -1348,7 +1351,7 @@ class SparkSqlAstBuilder(conf: SQLConf) extends AstBuilder {
 
         // SPARK-10310: Special cases LazySimpleSerDe
         val recordHandler = if (name == "org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe") {
-          Try(conf.getConfString(configKey)).toOption
+          Option(conf.getConfString(configKey, defaultConfigValue))
         } else {
           None
         }
@@ -1359,15 +1362,18 @@ class SparkSqlAstBuilder(conf: SQLConf) extends AstBuilder {
         val name = conf.getConfString("hive.script.serde",
           "org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe")
         val props = Seq("field.delim" -> "\t")
-        val recordHandler = Try(conf.getConfString(configKey)).toOption
+        val recordHandler = Option(conf.getConfString(configKey, defaultConfigValue))
         (Nil, Option(name), props, recordHandler)
     }
 
     val (inFormat, inSerdeClass, inSerdeProps, reader) =
-      format(inRowFormat, "hive.script.recordreader")
+      format(
+        inRowFormat, "hive.script.recordreader", "org.apache.hadoop.hive.ql.exec.TextRecordReader")
 
     val (outFormat, outSerdeClass, outSerdeProps, writer) =
-      format(outRowFormat, "hive.script.recordwriter")
+      format(
+        outRowFormat, "hive.script.recordwriter",
+        "org.apache.hadoop.hive.ql.exec.TextRecordWriter")
 
     ScriptInputOutputSchema(
       inFormat, outFormat,

sql/hive/src/test/resources/test_script.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+while read line
+do
+  echo "$line" | sed 's/\t/_/'
+done < /dev/stdin

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala

@@ -63,6 +63,17 @@ class SQLQuerySuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
   import hiveContext._
   import spark.implicits._
 
+  test("script") {
+    val df = Seq(("x1", "y1", "z1"), ("x2", "y2", "z2")).toDF("c1", "c2", "c3")
+    df.createOrReplaceTempView("script_table")
+    val query1 = sql(
+      """
+        |SELECT col1 FROM (from(SELECT c1, c2, c3 FROM script_table) tempt_table
+        |REDUCE c1, c2, c3 USING 'bash src/test/resources/test_script.sh' AS
+        |(col1 STRING, col2 STRING)) script_test_table""".stripMargin)
+    checkAnswer(query1, Row("x1_y1") :: Row("x2_y2") :: Nil)
+  }
+
   test("UDTF") {
     withUserDefinedFunction("udtf_count2" -> true) {
       sql(s"ADD JAR ${hiveContext.getHiveFile("TestUDTF.jar").getCanonicalPath()}")