Statically init typeActionMap in OpenSearchExprValueFactory. (#310)…

… (#1897)

Signed-off-by: Yury-Fridlyand <yury.fridlyand@improving.com>
(cherry picked from commit c8d42a7)

opensearch/src/main/java/org/opensearch/sql/opensearch/data/value/OpenSearchExprValueFactory.java

@@ -105,7 +105,7 @@ public void extendTypeMapping(Map<String, OpenSearchDataType> typeMapping) {
 
   private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
-  private final Map<ExprType, BiFunction<Content, ExprType, ExprValue>> typeActionMap =
+  private static final Map<ExprType, BiFunction<Content, ExprType, ExprValue>> typeActionMap =
       new ImmutableMap.Builder<ExprType, BiFunction<Content, ExprType, ExprValue>>()
           .put(OpenSearchDataType.of(OpenSearchDataType.MappingType.Integer),
               (c, dt) -> new ExprIntegerValue(c.intValue()))
@@ -126,10 +126,12 @@ public void extendTypeMapping(Map<String, OpenSearchDataType> typeMapping) {
           .put(OpenSearchDataType.of(OpenSearchDataType.MappingType.Boolean),
               (c, dt) -> ExprBooleanValue.of(c.booleanValue()))
           //Handles the creation of DATE, TIME & DATETIME
-          .put(OpenSearchDateType.of(TIME), this::createOpenSearchDateType)
-          .put(OpenSearchDateType.of(DATE), this::createOpenSearchDateType)
-          .put(OpenSearchDateType.of(TIMESTAMP), this::createOpenSearchDateType)
-          .put(OpenSearchDateType.of(DATETIME), this::createOpenSearchDateType)
+          .put(OpenSearchDateType.of(TIME), OpenSearchExprValueFactory::createOpenSearchDateType)
+          .put(OpenSearchDateType.of(DATE), OpenSearchExprValueFactory::createOpenSearchDateType)
+          .put(OpenSearchDateType.of(TIMESTAMP),
+              OpenSearchExprValueFactory::createOpenSearchDateType)
+          .put(OpenSearchDateType.of(DATETIME),
+              OpenSearchExprValueFactory::createOpenSearchDateType)
           .put(OpenSearchDataType.of(OpenSearchDataType.MappingType.Ip),
               (c, dt) -> new OpenSearchExprIpValue(c.stringValue()))
           .put(OpenSearchDataType.of(OpenSearchDataType.MappingType.GeoPoint),
@@ -222,7 +224,7 @@ private Optional<ExprType> type(String field) {
    * @param dataType - field data type
    * @return Parsed value
    */
-  private ExprValue parseDateTimeString(String value, OpenSearchDateType dataType) {
+  private static ExprValue parseDateTimeString(String value, OpenSearchDateType dataType) {
     List<DateFormatter> formatters = dataType.getAllNamedFormatters();
     formatters.addAll(dataType.getAllCustomFormatters());
     ExprCoreType returnFormat = (ExprCoreType) dataType.getExprType();
@@ -262,7 +264,7 @@ private ExprValue parseDateTimeString(String value, OpenSearchDateType dataType)
         "Construct %s from \"%s\" failed, unsupported format.", returnFormat, value));
   }
 
-  private ExprValue createOpenSearchDateType(Content value, ExprType type) {
+  private static ExprValue createOpenSearchDateType(Content value, ExprType type) {
     OpenSearchDateType dt = (OpenSearchDateType) type;
     ExprType returnFormat = dt.getExprType();