Make LwM2mValueConverterImpl singleton

@@ -91,7 +91,7 @@ public class LwM2MTransportRequest {
 
     @PostConstruct
     public void init() {
-        this.converter = new LwM2mValueConverterImpl();
+        this.converter = LwM2mValueConverterImpl.getInstance();
         executorResponse = Executors.newCachedThreadPool(
                 new NamedThreadFactory(String.format("LwM2M %s channel response", RESPONSE_CHANNEL)));
         executorResponseError = Executors.newCachedThreadPool(

@@ -73,7 +73,7 @@ public class LwM2MTransportServerConfiguration {
         builder.setEncoder(new DefaultLwM2mNodeEncoder());
         LwM2mNodeDecoder decoder = new DefaultLwM2mNodeDecoder();
         builder.setDecoder(decoder);
-        builder.setEncoder(new DefaultLwM2mNodeEncoder(new LwM2mValueConverterImpl()));
+        builder.setEncoder(new DefaultLwM2mNodeEncoder(LwM2mValueConverterImpl.getInstance()));
 
         /** Create CoAP Config */
         builder.setCoapConfig(getCoapConfig());
@@ -89,7 +89,7 @@ public class LwM2MTransportServerConfiguration {
         builder.setDtlsConfig(dtlsConfig);
 
         /** Use a magic converter to support bad type send by the UI. */
-        builder.setEncoder(new DefaultLwM2mNodeEncoder(new LwM2mValueConverterImpl()));
+        builder.setEncoder(new DefaultLwM2mNodeEncoder(LwM2mValueConverterImpl.getInstance()));
 
         /**  Create DTLS security mode
          * There can be only one DTLS security mode

@@ -123,7 +123,7 @@ public class LwM2MTransportService {
                 new NamedThreadFactory(String.format("LwM2M %s channel update registered", SERVICE_CHANNEL)));
         this.executorUnRegistered = Executors.newCachedThreadPool(
                 new NamedThreadFactory(String.format("LwM2M %s channel un registered", SERVICE_CHANNEL)));
-        this.converter = new LwM2mValueConverterImpl();
+        this.converter = LwM2mValueConverterImpl.getInstance();
     }
 
     /**

@@ -78,7 +78,7 @@ public class LwM2MClient implements Cloneable {
          * Key <objectId>, response<Value -> instance -> resources: value...>
          */
         this.responses = new ConcurrentHashMap<>();
-        this.converter = new LwM2mValueConverterImpl();
+        this.converter = LwM2mValueConverterImpl.getInstance();
     }
 
     /**

@@ -33,6 +33,12 @@ import java.util.Date;
 @Slf4j
 public class LwM2mValueConverterImpl implements LwM2mValueConverter {
 
+    private static final LwM2mValueConverterImpl INSTANCE = new LwM2mValueConverterImpl();
+
+    public static LwM2mValueConverterImpl getInstance() {
+        return INSTANCE;
+    }
+
     @Override
     public Object convertValue(Object value, Type currentType, Type expectedType, LwM2mPath resourcePath)
             throws CodecException {