[ECR-4395] Fix sonar bugs (#1547)

Author: bullet-tooth

exonum-java-binding/common/src/main/java/com/exonum/binding/common/hash/AbstractHasher.java

@@ -134,7 +134,7 @@ public <T> Hasher putObject(T instance, Funnel<? super T> funnel) {
     return this;
   }
 
-  @SuppressWarnings("EmptyMethod")
+  @SuppressWarnings({"EmptyMethod", "squid:S1206"})
   @Override
   @Deprecated
   public int hashCode() {

exonum-java-binding/core/src/main/java/com/exonum/binding/core/blockchain/Block.java

@@ -107,6 +107,8 @@ public final boolean isEmpty() {
    */
   public abstract ImmutableMap<String, ByteString> getAdditionalHeaders();
 
+  // TODO: remove after https://jira.sonarsource.com/browse/SONARJAVA-3377
+  @SuppressWarnings("squid:S1206")
   @Override
   public int hashCode() {
     // Use just the first 4 bytes of the SHA-256 hash of the binary object representation,

exonum-java-binding/core/src/main/java/com/exonum/binding/core/runtime/RuntimeTransport.java

@@ -58,8 +58,11 @@ public RuntimeTransport(Server server, @Named(SERVICE_WEB_SERVER_PORT) int port)
   void start() {
     try {
       server.start(port).get();
-    } catch (InterruptedException | ExecutionException e) {
+    } catch (ExecutionException e) {
       throw new IllegalStateException(e);
+    } catch (InterruptedException e) {
+      logger.error("Start services API server was interrupted", e);
+      Thread.currentThread().interrupt();
     }
   }
 

exonum-java-binding/core/src/main/java/com/exonum/binding/core/storage/indices/RustIterAdapter.java

@@ -46,12 +46,10 @@ public boolean hasNext() {
 
   @Override
   public E next() {
-    if (!hasNext()) {
-      throw new NoSuchElementException("Reached the end of the underlying collection. "
-          + "Use #hasNext to check if you have reached the end of the collection.");
-    }
-    Optional<E> nextElement = nextItem;
+    E element = nextItem.orElseThrow(
+        () -> new NoSuchElementException("Reached the end of the underlying collection. "
+            + "Use #hasNext to check if you have reached the end of the collection."));
     nextItem = rustIter.next();  // an after-the-next item
-    return nextElement.get();
+    return element;
   }
 }

exonum-java-binding/core/src/main/java/com/exonum/binding/core/storage/indices/ValueSetIndexProxy.java

@@ -250,6 +250,8 @@ public abstract static class Entry<E> {
 
     // Do not include (potentially) large value in the hash code: we already have a SHA-256 hash.
     @Override
+    // TODO: remove after https://jira.sonarsource.com/browse/SONARJAVA-3377
+    @SuppressWarnings("squid:S1206")
     public final int hashCode() {
       // Use just the first 4 bytes of the SHA-256 hash of the binary value,
       // as they will have close to uniform distribution.