Allow multiple date formats for date fields

Author: xhaggi

Diff for: src/main/java/org/springframework/data/elasticsearch/annotations/DateFormat.java

@@ -23,9 +23,9 @@
  * @author Jakub Vavrik
  * @author Tim te Beek
  * @author Peter-Josef Meisch
+ * @author Sascha Woo
  */
 public enum DateFormat {
-	none(""), //
 	custom(""), //
 	basic_date("uuuuMMdd"), //
 	basic_date_time("uuuuMMdd'T'HHmmss.SSSXXX"), //

Diff for: src/main/java/org/springframework/data/elasticsearch/annotations/Field.java

@@ -36,6 +36,7 @@
  * @author Aleksei Arsenev
  * @author Brian Kimmig
  * @author Morgan Lutz
+ * @author Sascha Woo
  */
 @Retention(RetentionPolicy.RUNTIME)
 @Target({ ElementType.FIELD, ElementType.ANNOTATION_TYPE })
@@ -65,7 +66,7 @@
 
 	boolean index() default true;
 
-	DateFormat format() default DateFormat.none;
+	DateFormat[] format() default { DateFormat.date_optional_time, DateFormat.epoch_millis };
 
 	String pattern() default "";
 

Diff for: src/main/java/org/springframework/data/elasticsearch/annotations/InnerField.java

@@ -40,7 +40,7 @@
 
 	boolean index() default true;
 
-	DateFormat format() default DateFormat.none;
+	DateFormat[] format() default { DateFormat.date_optional_time, DateFormat.epoch_millis };
 
 	String pattern() default "";
 

Diff for: src/main/java/org/springframework/data/elasticsearch/core/index/MappingParameters.java

@@ -17,6 +17,8 @@
 
 import java.io.IOException;
 import java.lang.annotation.Annotation;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -41,6 +43,7 @@
  * @author Aleksei Arsenev
  * @author Brian Kimmig
  * @author Morgan Lutz
+ * @author Sascha Woo
  * @since 4.0
  */
 public final class MappingParameters {
@@ -83,7 +86,7 @@ public final class MappingParameters {
 	private final boolean eagerGlobalOrdinals;
 	private final boolean enabled;
 	private final boolean fielddata;
-	private final DateFormat format;
+	private final DateFormat[] format;
 	@Nullable private final Integer ignoreAbove;
 	private final boolean ignoreMalformed;
 	private final boolean index;
@@ -226,8 +229,17 @@ public void writeTypeAndParametersTo(XContentBuilder builder) throws IOException
 
 		if (type != FieldType.Auto) {
 			builder.field(FIELD_PARAM_TYPE, type.name().toLowerCase());
-			if (type == FieldType.Date && format != DateFormat.none) {
-				builder.field(FIELD_PARAM_FORMAT, format == DateFormat.custom ? datePattern : format.toString());
+			if (type == FieldType.Date && format.length > 0) {
+				List<String> formats = new ArrayList<>();
+				for (int i = 0; i < format.length; i++) {
+					DateFormat dateFormat = format[i];
+					if (dateFormat == DateFormat.custom) {
+						formats.add(datePattern);
+					} else {
+						formats.add(format.toString());
+					}
+				}
+				builder.field(FIELD_PARAM_FORMAT, String.join("||", formats));
 			}
 		}