[SPARK-9794] [SQL] Fix datetime parsing in SparkSQL.

This fixes https://issues.apache.org/jira/browse/SPARK-9794 by using a real ISO8601 parser. (courtesy of the xml component of the standard java library)

cc: angelini

Author: Kevin Cox <kevincox@kevincox.ca>

Closes #8396 from kevincox/kevincox-sql-time-parsing.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/DateTimeUtils.scala

@@ -20,6 +20,7 @@ package org.apache.spark.sql.catalyst.util
 import java.sql.{Date, Timestamp}
 import java.text.{DateFormat, SimpleDateFormat}
 import java.util.{TimeZone, Calendar}
+import javax.xml.bind.DatatypeConverter;
 
 import org.apache.spark.unsafe.types.UTF8String
 
@@ -109,30 +110,22 @@ object DateTimeUtils {
   }
 
   def stringToTime(s: String): java.util.Date = {
-    if (!s.contains('T')) {
+    var indexOfGMT = s.indexOf("GMT");
+    if (indexOfGMT != -1) {
+      // ISO8601 with a weird time zone specifier (2000-01-01T00:00GMT+01:00)
+      val s0 = s.substring(0, indexOfGMT)
+      val s1 = s.substring(indexOfGMT + 3)
+      // Mapped to 2000-01-01T00:00+01:00
+      stringToTime(s0 + s1)
+    } else if (!s.contains('T')) {
       // JDBC escape string
       if (s.contains(' ')) {
         Timestamp.valueOf(s)
       } else {
         Date.valueOf(s)
       }
-    } else if (s.endsWith("Z")) {
-      // this is zero timezone of ISO8601
-      stringToTime(s.substring(0, s.length - 1) + "GMT-00:00")
-    } else if (s.indexOf("GMT") == -1) {
-      // timezone with ISO8601
-      val inset = "+00.00".length
-      val s0 = s.substring(0, s.length - inset)
-      val s1 = s.substring(s.length - inset, s.length)
-      if (s0.substring(s0.lastIndexOf(':')).contains('.')) {
-        stringToTime(s0 + "GMT" + s1)
-      } else {
-        stringToTime(s0 + ".0GMT" + s1)
-      }
     } else {
-      // ISO8601 with GMT insert
-      val ISO8601GMT: SimpleDateFormat = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm:ss.SSSz" )
-      ISO8601GMT.parse(s)
+      DatatypeConverter.parseDateTime(s).getTime()
     }
   }
 

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/util/DateTimeUtilsSuite.scala

@@ -136,6 +136,38 @@ class DateTimeUtilsSuite extends SparkFunSuite {
     assert(stringToDate(UTF8String.fromString("2015-031-8")).isEmpty)
   }
 
+  test("string to time") {
+    // Tests with UTC.
+    var c = Calendar.getInstance(TimeZone.getTimeZone("UTC"))
+    c.set(Calendar.MILLISECOND, 0)
+
+    c.set(1900, 0, 1, 0, 0, 0)
+    assert(stringToTime("1900-01-01T00:00:00GMT-00:00") === c.getTime())
+
+    c.set(2000, 11, 30, 10, 0, 0)
+    assert(stringToTime("2000-12-30T10:00:00Z") === c.getTime())
+
+    // Tests with set time zone.
+    c.setTimeZone(TimeZone.getTimeZone("GMT-04:00"))
+    c.set(Calendar.MILLISECOND, 0)
+
+    c.set(1900, 0, 1, 0, 0, 0)
+    assert(stringToTime("1900-01-01T00:00:00-04:00") === c.getTime())
+
+    c.set(1900, 0, 1, 0, 0, 0)
+    assert(stringToTime("1900-01-01T00:00:00GMT-04:00") === c.getTime())
+
+    // Tests with local time zone.
+    c.setTimeZone(TimeZone.getDefault())
+    c.set(Calendar.MILLISECOND, 0)
+
+    c.set(2000, 11, 30, 0, 0, 0)
+    assert(stringToTime("2000-12-30") === new Date(c.getTimeInMillis()))
+
+    c.set(2000, 11, 30, 10, 0, 0)
+    assert(stringToTime("2000-12-30 10:00:00") === new Timestamp(c.getTimeInMillis()))
+  }
+
   test("string to timestamp") {
     var c = Calendar.getInstance()
     c.set(1969, 11, 31, 16, 0, 0)