Make some Java classes proper utilities

Made the design cleaner by marking Java classes as `final`
and excitability declaring their default constructors as `private`.
This change makes the code coverage reports more accurate.
Fixes #4902.

changelog.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 [Fix the mismatch error by `fromXml` API while the field has the name annotation](https://github.com/ballerina-platform/ballerina-standard-library/issues/3802)
+[Make some of the Java classes proper utility classes](https://github.com/ballerina-platform/ballerina-standard-library/issues/4902)
 
 ## [2.4.3] - 2023-05-12
 

native/src/main/java/io/ballerina/stdlib/xmldata/MapFromXml.java

@@ -47,7 +47,9 @@
  *
  * @since 2.3.0
  */
-public class MapFromXml {
+public final class MapFromXml {
+
+    private MapFromXml() {}
 
     @SuppressWarnings("unchecked")
     public static Object fromXml(BXml xml, BTypedesc type) {

native/src/main/java/io/ballerina/stdlib/xmldata/XmlToRecord.java

@@ -39,7 +39,9 @@
  *
  * @since 2.0.2
  */
-public class XmlToRecord {
+public final class XmlToRecord {
+
+    private XmlToRecord() {}
 
     public static Object toRecord(BXml xml, boolean preserveNamespaces, BTypedesc type) {
         return toRecord(xml, preserveNamespaces, Constants.UNDERSCORE, type);

native/src/main/java/io/ballerina/stdlib/xmldata/utils/XmlDataUtils.java

@@ -46,7 +46,9 @@
  *
  * @since 1.1.0
  */
-public class XmlDataUtils {
+public final class XmlDataUtils {
+
+    private XmlDataUtils() {}
 
     private static final String ERROR = "Error";
     private static final String ATTRIBUTE_PREFIX = "attribute_";