[#27] Add more modules to CheckStyle

Signed-off-by: Ori Bruk <o.bruk@yadro.com>

checkstyle.xml

@@ -10,6 +10,7 @@
     <module name="FileTabCharacter">
         <property name="eachLine" value="true"/>
     </module>
+    <module name="NewlineAtEndOfFile"/>
 
     <!-- Checks for Size Violations.                    -->
     <!-- See http://checkstyle.sf.net/config_sizes.html -->
@@ -20,6 +21,15 @@
     <module name="TreeWalker">
         <property name="tabWidth" value="4"/>
 
+        <module name="Regexp">
+            <property name="message" value="Blank line at end of block is not allowed"/>
+            <property name="format" value="^\s*$^\s*\}"/>
+            <property name="ignoreComments" value="true"/>
+            <property name="illegalPattern" value="true"/>
+        </module>
+
+        <module name="HideUtilityClassConstructor" />
+
         <module name="SuppressWarningsHolder" />
 
         <!-- Checks for Naming Conventions.                  -->

client/src/main/java/info/frostfs/sdk/services/ContextAccessor.java

@@ -10,5 +10,4 @@ public class ContextAccessor {
     public ContextAccessor(ClientEnvironment context) {
         this.context = context;
     }
-
 }

client/src/main/java/info/frostfs/sdk/services/impl/SessionToolsImpl.java

@@ -23,5 +23,4 @@ public class SessionToolsImpl extends ContextAccessor implements SessionTools {
 
         return SessionMapper.deserializeSessionToken(sessionToken.getToken());
     }
-
 }

client/src/main/java/info/frostfs/sdk/services/impl/interceptor/Labels.java

@@ -9,14 +9,21 @@ import java.util.Collections;
 import java.util.List;
 
 public class Labels {
-    /** Merges two string lists into an array, maintaining order of first list then second list. */
+    private Labels() {
+    }
+
+    /**
+     * Merges two string lists into an array, maintaining order of first list then second list.
+     */
     static String[] asArray(List<String> firstList, List<String> secondList) {
         List<String> list = new ArrayList<>(firstList);
         list.addAll(secondList);
         return list.toArray(new String[0]);
     }
 
-    /** Converts a list of strings to a list of grpc metadata keys. */
+    /**
+     * Converts a list of strings to a list of grpc metadata keys.
+     */
     static List<Key<String>> metadataKeys(List<String> headerNames) {
         List<Key<String>> keys = new ArrayList<>();
         for (String name : headerNames) {
@@ -41,7 +48,9 @@ public class Labels {
         return Collections.unmodifiableList(labels);
     }
 
-    /** Adds standard labels, as well as custom ones, in order, to a given collector. */
+    /**
+     * Adds standard labels, as well as custom ones, in order, to a given collector.
+     */
     static <T> T addLabels(SimpleCollector<T> collector, List<String> labels, GrpcMethod method) {
         List<String> allLabels = new ArrayList<>();
         allLabels.add(method.type());

client/src/main/java/info/frostfs/sdk/tools/RequestSigner.java

@@ -119,5 +119,4 @@ public class RequestSigner {
         MessageHelper.setField(verifyBuilder, ORIGIN_SIGNATURE_FIELD_NAME, signMessagePart(key, verifyOrigin));
         MessageHelper.setField(request, VERIFY_HEADER_FIELD_NAME, verifyBuilder.build());
     }
-
 }

client/src/main/java/info/frostfs/sdk/utils/Validator.java

@@ -15,6 +15,9 @@ import static info.frostfs.sdk.constants.ErrorConst.FIELDS_DELIMITER_COMMA;
 import static java.util.Objects.isNull;
 
 public class Validator {
+    private Validator() {
+    }
+
     public static <T> void validate(T object) {
         StringBuilder errorMessage = new StringBuilder();
         process(object, errorMessage);

client/src/main/java/info/frostfs/sdk/utils/WaitUtil.java

@@ -1,6 +1,8 @@
 package info.frostfs.sdk.utils;
 
 public class WaitUtil {
+    private WaitUtil() {
+    }
 
     public static void sleep(long ms) {
         try {

models/src/main/java/info/frostfs/sdk/constants/FilterConst.java

@@ -46,4 +46,7 @@ public class FilterConst {
 
     // FILTER_HEADER_PHY is a filter key to check if an object physically stored on a node.
     public static final String FILTER_HEADER_PHY = HEADER_PREFIX + "PHY";
+
+    private FilterConst() {
+    }
 }