Add SPI jvm option to SystemJvmOptions (#50916)

Adding back accidentally removed jvm option that is required to enforce
start of the week = Monday in IsoCalendarDataProvider.
Adding a `feature` to yml test in order to skip running it in JDK8

commit that removed it 398c802
commit that backports SystemJvmOptions c4fbda3
relates 7.x backport of code that enforces CalendarDataProvider use #48349

distribution/tools/launchers/src/main/java/org/elasticsearch/tools/launchers/SystemJvmOptions.java

@@ -19,6 +19,8 @@
 
 package org.elasticsearch.tools.launchers;
 
+import org.elasticsearch.tools.java_version_checker.JavaVersion;
+
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -60,11 +62,26 @@ final class SystemJvmOptions {
             // log4j 2
             "-Dlog4j.shutdownHookEnabled=false",
             "-Dlog4j2.disable.jmx=true",
-            /*
+
+            javaLocaleProviders()));
+    }
+
+    private static String javaLocaleProviders() {
+        /**
+         *  SPI setting is used to allow loading custom CalendarDataProvider
+         *  in jdk8 it has to be loaded from jre/lib/ext,
+         *  in jdk9+ it is already within ES project and on a classpath
+         *
          *  Due to internationalization enhancements in JDK 9 Elasticsearch need to set the provider to COMPAT otherwise time/date
          *  parsing will break in an incompatible way for some date patterns and locales.
+         *  //TODO COMPAT will be deprecated in jdk14 https://bugs.openjdk.java.net/browse/JDK-8232906
+         * See also: documentation in <code>server/org.elasticsearch.common.time.IsoCalendarDataProvider</code>
          */
-            "-Djava.locale.providers=COMPAT"));
+        if(JavaVersion.majorVersion(JavaVersion.CURRENT) == 8){
+            return "-Djava.locale.providers=SPI,JRE";
+        } else {
+            return "-Djava.locale.providers=SPI,COMPAT";
+        }
     }
 
 }

rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/310_date_agg_per_day_of_week.yml

@@ -0,0 +1,44 @@
+
+setup:
+  - skip:
+      version: " - 7.5.99"
+      reason:  "Start of the week Monday was backported to 7.6"
+      features: "spi_on_classpath_jdk9"
+
+  - do:
+      indices.create:
+        index: test
+        body:
+          mappings:
+            properties:
+              date:
+                type: date
+  - do:
+      index:
+        index: test
+        id:    1
+        body:  { "date": "2009-11-15T14:12:12" }
+  - do:
+      indices.refresh:
+        index: [test]
+---
+# The inserted document has a field date=2009-11-15T14:12:12 which is Sunday.
+# When aggregating per day of the week this should be considered as last day of the week (7)
+# and this value should be used in 'key_as_string'
+"Date aggregation per day of week":
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: test
+        body:
+          aggregations:
+            test:
+              "date_histogram": {
+                "field": "date",
+                "calendar_interval": "day",
+                "format": "e",
+                "offset": 0
+              }
+  - match: {hits.total: 1}
+  - length: { aggregations.test.buckets: 1 }
+  - match: { aggregations.test.buckets.0.key_as_string: "7" }

server/src/main/java/org/elasticsearch/common/time/IsoCalendarDataProvider.java

@@ -22,6 +22,13 @@ import java.util.Calendar;
 import java.util.Locale;
 import java.util.spi.CalendarDataProvider;
 
+/**
+ * This class is loaded by JVM SPI mechanism in order to provide ISO compatible behaviour for week calculations using java.time.
+ * It defines start of the week as Monday and requires 4 days in the first week of the year.
+ * This class overrides default behaviour for Locale.ROOT (start of the week Sunday, minimum 1 day in the first week of the year).
+ * Java SPI mechanism requires java.locale.providers to contain SPI value (i.e. java.locale.providers=SPI,COMPAT)
+ * @see <a href="https://en.wikipedia.org/wiki/ISO_week_date">ISO week date</a>
+ */
 public class IsoCalendarDataProvider extends CalendarDataProvider {
 
     @Override

server/src/test/java/org/elasticsearch/common/joda/JavaJodaTimeDuellingTests.java

@@ -29,6 +29,7 @@ import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
 import org.joda.time.format.DateTimeFormat;
 import org.joda.time.format.ISODateTimeFormat;
+import org.junit.BeforeClass;
 
 import java.time.ZoneId;
 import java.time.ZoneOffset;
@@ -47,6 +48,14 @@ public class JavaJodaTimeDuellingTests extends ESTestCase {
         return false;
     }
 
+    @BeforeClass
+    public static void checkJvmProperties(){
+        boolean runtimeJdk8 = JavaVersion.current().getVersion().get(0) == 8;
+        assert (runtimeJdk8 && ("SPI,JRE".equals(System.getProperty("java.locale.providers"))))
+            || (false == runtimeJdk8 && ("SPI,COMPAT".equals(System.getProperty("java.locale.providers"))))
+            : "`-Djava.locale.providers` needs to be set";
+    }
+
     public void testTimezoneParsing() {
         /** this testcase won't work in joda. See comment in {@link #testPartialTimeParsing()}
          *  assertSameDateAs("2016-11-30T+01", "strict_date_optional_time", "strict_date_optional_time");

test/framework/src/main/java/org/elasticsearch/test/rest/yaml/Features.java

@@ -19,11 +19,12 @@
 
 package org.elasticsearch.test.rest.yaml;
 
+import org.elasticsearch.bootstrap.JavaVersion;
+import org.elasticsearch.test.rest.ESRestTestCase;
+
 import java.util.Arrays;
 import java.util.List;
 
-import org.elasticsearch.test.rest.ESRestTestCase;
-
 import static java.util.Collections.unmodifiableList;
 
 /**
@@ -50,6 +51,7 @@ public final class Features {
             "transform_and_set",
             "arbitrary_key"
     ));
+    private static final String SPI_ON_CLASSPATH_SINCE_JDK_9 = "spi_on_classpath_jdk9";
 
     private Features() {
 
@@ -68,10 +70,18 @@ public final class Features {
                 if (ESRestTestCase.hasXPack()) {
                     return false;
                 }
-            } else if (false == SUPPORTED.contains(feature)) {
+            } else if (false == isSupported(feature)) {
                 return false;
             }
         }
         return true;
     }
+
+    private static boolean isSupported(String feature) {
+        if(feature.equals(SPI_ON_CLASSPATH_SINCE_JDK_9) &&
+            JavaVersion.current().compareTo(JavaVersion.parse("9")) >= 0) {
+            return true;
+        }
+        return SUPPORTED.contains(feature) ;
+    }
 }