diff --git a/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/BucketOperator.java b/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/BucketOperator.java
index 19fd02e..6f928bd 100644
--- a/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/BucketOperator.java
+++ b/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/BucketOperator.java
@@ -28,9 +28,11 @@ import software.amazon.awssdk.services.s3.model.ListBucketsRequest;
 import software.amazon.awssdk.services.s3.model.ListBucketsResponse;
 import software.amazon.awssdk.services.s3.model.ListObjectsV2Request;
 import software.amazon.awssdk.services.s3.model.ListObjectsV2Response;
+import software.amazon.awssdk.services.s3.model.NoSuchKeyException;
 import software.amazon.awssdk.services.s3.model.PutObjectRequest;
 import software.amazon.awssdk.services.s3.model.PutObjectResponse;
 import software.amazon.awssdk.services.s3.model.S3Object;
+import software.amazon.awssdk.services.s3.model.S3Response;
 
 public class BucketOperator {
 	
@@ -156,9 +158,21 @@ public class BucketOperator {
       * @param bucket
       * @param key
       * @param file
+     * @param replace 
       * @return
       */
-     public static PutObjectResponse putObject(String bucket, String key, File file) {
+     public static S3Response putObject(String bucket, String key, File file, boolean replace) {
+    	 if(!replace) {
+    		 GetObjectRequest getObjectRequest = GetObjectRequest.builder()
+    	 		        .bucket(bucket)
+    	 		        .key(key)
+    	 		        .build();
+    		 try {
+    			 return client.getObject(getObjectRequest).response();
+    		 }catch (NoSuchKeyException e) {
+    			 
+    		 }
+    	 }
     	 PutObjectRequest objectRequest = PutObjectRequest.builder()
     		        .bucket(bucket)
     		        .key(key)
@@ -184,13 +198,20 @@ public class BucketOperator {
     		return response.toString();
      }
      
+     /**
+      * Get object length in bytes
+      * @param bucket
+      * @param key
+      * @return
+      * @throws IOException
+      */
+    		 
      public static Long getObjectSize( String bucket, String key)
     	        throws IOException {
     	 GetObjectRequest getObjectRequest = GetObjectRequest.builder()
  		        .bucket(bucket)
  		        .key(key)
  		        .build();
-
  		return client.getObject(getObjectRequest).response().contentLength();
     }
      
diff --git a/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/S3PluginManager.java b/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/S3PluginManager.java
index cb93763..06dcc7f 100644
--- a/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/S3PluginManager.java
+++ b/src/main/java/org/gcube/contentmanagement/blobstorage/transport/plugin/S3PluginManager.java
@@ -40,14 +40,15 @@ import com.mongodb.MongoException;
 
 public class S3PluginManager extends TransportManager {
 
-	Region region = Region.US_EAST_1;
-	final String END_POINT = "https://s3.wasabisys.com";
+
 	S3Client s3;
 	private Logger logger = LoggerFactory.getLogger(S3PluginManager.class);
 	
 // THE FOLLOWING FIELDS SHOULD BE RETRIEVED FROM SERVICEENDPOINT	
 	static final String ACCESS_KEY="UXMKEBMZBDROS5K9HREG";
 	static final String SECRET_ACCESS_KEY="0Mqu8gmzcZ09wuqqKZwNmuS5bYC549MlZhvfgv6W";
+	Region region = Region.US_EAST_1;
+	final String END_POINT = "https://s3.wasabisys.com";
 	static final String bucket="gcube-home-test-access";
 	
 	
@@ -87,7 +88,7 @@ public class S3PluginManager extends TransportManager {
 		logger.info("put method invoked ");
 		File file= new File(upload.getResource().getLocalPath());
 //		return BucketOperator.getInstance(s3).putObject(bucket, Utils.convertToS3Format(upload.getResource().getRemotePath()), file).toString();
-		int hashcode=BucketOperator.getInstance(s3).putObject(bucket, Utils.convertToS3Format(upload.getResource().getRemotePath()), file).hashCode();
+		int hashcode=BucketOperator.getInstance(s3).putObject(bucket, Utils.convertToS3Format(upload.getResource().getRemotePath()), file, upload.isReplaceOption()).hashCode();
 		return hashcode+"";
 	}