Bug fix, using Local.Root when format the string

common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/utils/StringUtils.java

@@ -16,6 +16,8 @@
 package com.amazon.opendistroforelasticsearch.sql.common.utils;
 
 import com.google.common.base.Strings;
+import java.util.IllegalFormatException;
+import java.util.Locale;
 
 public class StringUtils {
   /**
@@ -60,6 +62,23 @@ public static String unquoteIdentifier(String identifier) {
     }
   }
 
+  /**
+   * Returns a formatted string using the specified format string and
+   * arguments, as well as the {@link Locale#ROOT} locale.
+   *
+   * @param format format string
+   * @param args   arguments referenced by the format specifiers in the format string
+   * @return A formatted string
+   * @throws IllegalFormatException If a format string contains an illegal syntax, a format
+   *                                specifier that is incompatible with the given arguments,
+   *                                insufficient arguments given the format string, or other
+   *                                illegal conditions.
+   * @see java.lang.String#format(Locale, String, Object...)
+   */
+  public static String format(final String format, Object... args) {
+    return String.format(Locale.ROOT, format, args);
+  }
+
   private static boolean isQuoted(String text, String mark) {
     return !Strings.isNullOrEmpty(text) && text.startsWith(mark) && text.endsWith(mark);
   }

integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/DateTimeFunctionIT.java

@@ -21,6 +21,7 @@
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifySchema;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifySome;
 
+import com.amazon.opendistroforelasticsearch.sql.common.utils.StringUtils;
 import java.io.IOException;
 import org.json.JSONObject;
 import org.junit.jupiter.api.Test;
@@ -371,7 +372,7 @@ public void testToDays() throws IOException {
   }
 
   private void week(String date, int mode, int expectedResult) throws IOException {
-    JSONObject result = executeQuery(String.format(
+    JSONObject result = executeQuery(StringUtils.format(
         "source=%s | eval f = week(date('%s'), %d) | fields f", TEST_INDEX_DATE, date, mode));
     verifySchema(result, schema("f", null, "integer"));
     verifySome(result.getJSONArray("datarows"), rows(expectedResult));