style: make utility classes proper utilities

cloudinary-core/src/main/java/com/cloudinary/SmartUrlEncoder.java

@@ -3,7 +3,9 @@
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 
-public class SmartUrlEncoder {
+public final class SmartUrlEncoder {
+    private SmartUrlEncoder() {}
+
     public static String encode(String input) {
         try {
             return URLEncoder.encode(input, "UTF-8").replace("%2F", "/").replace("%3A", ":").replace("+", "%20");

cloudinary-core/src/main/java/com/cloudinary/Util.java

@@ -8,7 +8,9 @@
 import java.security.NoSuchAlgorithmException;
 import java.util.*;
 
-public class Util {
+public final class Util {
+    private Util() {}
+
     static final String[] BOOLEAN_UPLOAD_OPTIONS = new String[]{"backup", "exif", "faces", "colors", "image_metadata", "use_filename", "unique_filename",
             "eager_async", "invalidate", "discard_original_filename", "overwrite", "phash", "return_delete_token", "async", "quality_analysis", "cinemagraph_analysis",
             "accessibility_analysis", "use_filename_as_display_name", "use_asset_folder_as_public_id_prefix", "unique_display_name", "media_metadata", "visual_search",

cloudinary-core/src/main/java/com/cloudinary/utils/Base64Map.java

@@ -3,7 +3,9 @@
 import java.util.HashMap;
 import java.util.Map;
 
-public class Base64Map {
+public final class Base64Map {
+    private Base64Map() {}
+
     public static Map<String, String> values;
 
     static {

cloudinary-core/src/main/java/com/cloudinary/utils/HtmlEscape.java

@@ -16,7 +16,8 @@
  *         this program code.
  */
 
-public class HtmlEscape {
+public final class HtmlEscape {
+    private HtmlEscape() {}
 
     private static char[] hex = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
 

cloudinary-core/src/main/java/com/cloudinary/utils/ObjectUtils.java

@@ -11,7 +11,9 @@
 import java.util.*;
 
 
-public class ObjectUtils {
+public final class ObjectUtils {
+    private ObjectUtils() {}
+
     /**
      * Formats a Date as an ISO-8601 string representation.
      * @param date Date to format

cloudinary-core/src/main/java/com/cloudinary/utils/StringUtils.java

@@ -8,7 +8,9 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-public class StringUtils {
+public final class StringUtils {
+    private StringUtils() {}
+
     public static final String EMPTY = "";
 
     /**

cloudinary-http5/src/main/java/com/cloudinary/http5/ApiUtils.java

@@ -10,7 +10,8 @@
 
 import java.util.*;
 
-public class ApiUtils {
+public final class ApiUtils {
+    private ApiUtils() {}
 
     public static void setTimeouts(HttpUriRequestBase request, Map<String, ? extends Object> options) {
         RequestConfig config = request.getConfig();

cloudinary-taglib/src/main/java/com/cloudinary/Singleton.java

@@ -10,7 +10,8 @@
  *
  * @author jpollak
  */
-public class Singleton {
+public final class Singleton {
+    private Singleton() {}
 
     private static Cloudinary cloudinary;
 

cloudinary-test-common/src/main/java/com/cloudinary/test/AbstractApiTest.java

@@ -670,7 +670,7 @@ public void testRateLimits() throws Exception {
 
     @Test
     public void testConfiguration() throws Exception {
-        ApiResponse result = cloudinary.api().configuration(new ObjectUtils().asMap("settings", true));
+        ApiResponse result = cloudinary.api().configuration(ObjectUtils.asMap("settings", true));
         Map settings = (Map) result.get("settings");
         Assert.assertNotNull(settings.get("folder_mode"));
     }

cloudinary-test-common/src/main/java/com/cloudinary/test/MetadataTestHelper.java

@@ -6,7 +6,9 @@
 import com.cloudinary.metadata.MetadataValidation;
 import com.cloudinary.metadata.StringMetadataField;
 
-public class MetadataTestHelper {
+public final class MetadataTestHelper {
+    private MetadataTestHelper() {}
+
     public static StringMetadataField newFieldInstance(String label, Boolean mandatory) throws Exception {
         StringMetadataField field = new StringMetadataField();
         field.setLabel(label);

cloudinary-test-common/src/main/java/com/cloudinary/test/helpers/Feature.java

@@ -1,6 +1,8 @@
 package com.cloudinary.test.helpers;
 
-public class Feature {
+public final class Feature {
+    private Feature() {}
+
     public static final String ALL = "all";
     public static final String DYNAMIC_FOLDERS = "dynamic_folders";
     public static final String BACKEDUP_ASSETS = "backedup_assets";