[SPARK-31878][SQL] Create date formatter only once in HiveResult

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

@@ -19,10 +19,10 @@ package org.apache.spark.sql.execution
 
 import java.nio.charset.StandardCharsets
 import java.sql.{Date, Timestamp}
-import java.time.{Instant, LocalDate}
+import java.time.{Instant, LocalDate, ZoneOffset}
 
 import org.apache.spark.sql.Row
-import org.apache.spark.sql.catalyst.util.{DateFormatter, DateTimeUtils, TimestampFormatter}
+import org.apache.spark.sql.catalyst.util.{DateFormatter, DateTimeUtils, LegacyDateFormats, TimestampFormatter}
 import org.apache.spark.sql.execution.command.{DescribeCommandBase, ExecutedCommandExec, ShowTablesCommand, ShowViewsCommand}
 import org.apache.spark.sql.execution.datasources.v2.{DescribeTableExec, ShowTablesExec}
 import org.apache.spark.sql.internal.SQLConf
@@ -72,9 +72,23 @@ object HiveResult {
     }
   }
 
-  private def zoneId = DateTimeUtils.getZoneId(SQLConf.get.sessionLocalTimeZone)
-  private def dateFormatter = DateFormatter(zoneId)
-  private def timestampFormatter = TimestampFormatter.getFractionFormatter(zoneId)
+  // We can create the date formatter only once because it does not depend on Spark's
+  // session time zone controlled by the SQL config `spark.sql.session.timeZone`.
+  // The `zoneId` parameter is used only in parsing of special date values like `now`,
+  // `yesterday` and etc. but not in date formatting. While formatting of:
+  // - `java.time.LocalDate`, zone id is not used by `DateTimeFormatter` at all.
+  // - `java.sql.Date`, the date formatter delegates formatting to the legacy formatter
+  //   which uses the default system time zone `TimeZone.getDefault`. This works correctly
+  //   due to `DateTimeUtils.toJavaDate` which is based on the system time zone too.
+  private val dateFormatter = DateFormatter(
+    format = DateFormatter.defaultPattern,
+    // We can set any time zone id. UTC was taken for simplicity.
+    zoneId = ZoneOffset.UTC,
+    locale = DateFormatter.defaultLocale,
+    // Use `FastDateFormat` as the legacy formatter because it is thread-safe.
+    legacyFormat = LegacyDateFormats.FAST_DATE_FORMAT)
+  private def timestampFormatter = TimestampFormatter.getFractionFormatter(
+    DateTimeUtils.getZoneId(SQLConf.get.sessionLocalTimeZone))
 
   /** Formats a datum (based on the given data type) and returns the string representation. */
   def toHiveString(a: (Any, DataType), nested: Boolean = false): String = a match {

sql/core/src/test/scala/org/apache/spark/sql/execution/HiveResultSuite.scala

@@ -17,21 +17,27 @@
 
 package org.apache.spark.sql.execution
 
+import org.apache.spark.sql.catalyst.util.DateTimeTestUtils
 import org.apache.spark.sql.connector.InMemoryTableCatalog
+import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.{ExamplePoint, ExamplePointUDT, SharedSparkSession}
 
 class HiveResultSuite extends SharedSparkSession {
   import testImplicits._
 
   test("date formatting in hive result") {
-    val dates = Seq("2018-12-28", "1582-10-03", "1582-10-04", "1582-10-15")
-    val df = dates.toDF("a").selectExpr("cast(a as date) as b")
-    val executedPlan1 = df.queryExecution.executedPlan
-    val result = HiveResult.hiveResultString(executedPlan1)
-    assert(result == dates)
-    val executedPlan2 = df.selectExpr("array(b)").queryExecution.executedPlan
-    val result2 = HiveResult.hiveResultString(executedPlan2)
-    assert(result2 == dates.map(x => s"[$x]"))
+    DateTimeTestUtils.outstandingTimezonesIds.foreach { zoneId =>
+      withSQLConf(SQLConf.SESSION_LOCAL_TIMEZONE.key -> zoneId) {
+        val dates = Seq("2018-12-28", "1582-10-03", "1582-10-04", "1582-10-15")
+        val df = dates.toDF("a").selectExpr("cast(a as date) as b")
+        val executedPlan1 = df.queryExecution.executedPlan
+        val result = HiveResult.hiveResultString(executedPlan1)
+        assert(result == dates)
+        val executedPlan2 = df.selectExpr("array(b)").queryExecution.executedPlan
+        val result2 = HiveResult.hiveResultString(executedPlan2)
+        assert(result2 == dates.map(x => s"[$x]"))
+      }
+    }
   }
 
   test("timestamp formatting in hive result") {