diff --git a/src/main/java/org/nrg/xnat/archive/DicomZipImporter.java b/src/main/java/org/nrg/xnat/archive/DicomZipImporter.java
index b2267f4daba7e4e24acb41108842c813381d0758..32621fb5337f54cee03b31e606a5fcad64925dbb 100644
--- a/src/main/java/org/nrg/xnat/archive/DicomZipImporter.java
+++ b/src/main/java/org/nrg/xnat/archive/DicomZipImporter.java
@@ -32,7 +32,7 @@ import org.nrg.xnat.restlet.util.FileWriterWrapperI;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 
-@ImporterHandler(handler = "DICOM-zip", allowCallsWithoutFiles = false)
+@ImporterHandler(handler = ImporterHandlerA.DICOM_ZIP_IMPORTER)
 public final class DicomZipImporter extends ImporterHandlerA {
     private final InputStream in;
     private final Object listenerControl;
diff --git a/src/main/java/org/nrg/xnat/archive/GradualDicomImporter.java b/src/main/java/org/nrg/xnat/archive/GradualDicomImporter.java
index ffa912bfcf1ec1ec0c0670886e663a05ef1d9f26..236379e3a87f060a03d53f7e6fed6754044ec497 100644
--- a/src/main/java/org/nrg/xnat/archive/GradualDicomImporter.java
+++ b/src/main/java/org/nrg/xnat/archive/GradualDicomImporter.java
@@ -64,7 +64,7 @@ import java.util.concurrent.Callable;
 
 @SuppressWarnings("ThrowFromFinallyBlock")
 @Service
-@ImporterHandler(handler = "DICOM-zip", allowCallsWithoutFiles = false)
+@ImporterHandler(handler = ImporterHandlerA.GRADUAL_DICOM_IMPORTER)
 public class GradualDicomImporter extends ImporterHandlerA {
     public static final String SENDER_AE_TITLE_PARAM = "Sender-AE-Title";
     public static final String SENDER_ID_PARAM = "Sender-ID";
diff --git a/src/main/java/org/nrg/xnat/restlet/actions/SessionImporter.java b/src/main/java/org/nrg/xnat/restlet/actions/SessionImporter.java
index 415d80201bd8795fe7a4097fb37a2190ab7e4128..adb4a73788ae5e46376e7060b936c8ff39cb9e54 100644
--- a/src/main/java/org/nrg/xnat/restlet/actions/SessionImporter.java
+++ b/src/main/java/org/nrg/xnat/restlet/actions/SessionImporter.java
@@ -46,7 +46,7 @@ import org.nrg.xnat.turbine.utils.XNATSessionPopulater;
 import org.restlet.data.Status;
 import org.xml.sax.SAXException;
 
-@ImporterHandler(handler = "SI", allowCallsWithoutFiles = false)
+@ImporterHandler(handler = ImporterHandlerA.SESSION_IMPORTER)
 public class SessionImporter extends ImporterHandlerA implements Callable<List<String>> {
 
 	static Logger logger = Logger.getLogger(SessionImporter.class);
diff --git a/src/main/java/org/nrg/xnat/restlet/actions/XarImporter.java b/src/main/java/org/nrg/xnat/restlet/actions/XarImporter.java
index 33cc7c759f0c7e948e836a012a3bdc71e067edbc..dde32a013556040efae1496a8a442435767beadf 100644
--- a/src/main/java/org/nrg/xnat/restlet/actions/XarImporter.java
+++ b/src/main/java/org/nrg/xnat/restlet/actions/XarImporter.java
@@ -52,12 +52,12 @@ import org.nrg.xnat.turbine.utils.ArcSpecManager;
 import org.nrg.xnat.utils.WorkflowUtils;
 import org.xml.sax.SAXException;
 
-@ImporterHandler(handler = "XAR", allowCallsWithoutFiles = false)
+@ImporterHandler(handler = ImporterHandlerA.XAR_IMPORTER)
 public class XarImporter extends ImporterHandlerA implements Callable<List<String>> {
 
-	static final String[] zipExtensions={".zip",".jar",".rar",".ear",".gar",".xar"};
+	private static final String[] zipExtensions={".zip",".jar",".rar",".ear",".gar",".xar"};
 
-	static Logger logger = Logger.getLogger(XarImporter.class);
+	private static final Logger logger = Logger.getLogger(XarImporter.class);
 
 	private final FileWriterWrapperI fw;
 	private final UserI user;
@@ -66,19 +66,19 @@ public class XarImporter extends ImporterHandlerA implements Callable<List<Strin
 	
 	/**
 	 * 
-	 * @param listenerControl
-	 * @param u
-	 * @param session
-	 * @param overwrite:   'append' means overwrite, but preserve un-modified content (don't delete anything)
-	 *                      'delete' means delete the pre-existing content.
-	 * @param additionalValues: should include project, subject_ID and label (if session is null)
+	 * @param listenerControl     The listener.
+	 * @param u                   The user.
+     * @param fw                  The file writer wrapper.
+     * @param params              Parameters to the operation, including overwrite, 'append' means overwrite, but
+     *                            preserve un-modified content (don't delete anything), 'delete' means delete the
+     *                            pre-existing content. Should include project, subject_ID and label if session is null.
 	 */
 	public XarImporter(final Object listenerControl, final UserI u, final FileWriterWrapperI fw, final Map<String,Object> params) {
 		super(listenerControl, u, fw, params);
 		this.user=u;
 		this.fw=fw;
 		this.params=params;
-		this.urlList=new ArrayList<String>();
+		this.urlList= new ArrayList<>();
 	}
 	
 	//@SuppressWarnings("serial")
diff --git a/src/main/java/org/nrg/xnat/restlet/actions/importer/ImporterHandlerA.java b/src/main/java/org/nrg/xnat/restlet/actions/importer/ImporterHandlerA.java
index e84358d0321293205465d50341d80025182e6a35..5b3237b4f84d2cff377995d75f5e71c2d0a5e4ac 100644
--- a/src/main/java/org/nrg/xnat/restlet/actions/importer/ImporterHandlerA.java
+++ b/src/main/java/org/nrg/xnat/restlet/actions/importer/ImporterHandlerA.java
@@ -47,18 +47,18 @@ public abstract class ImporterHandlerA  extends StatusProducer implements Callab
 
     public abstract List<String> call() throws ClientException, ServerException;
 
-    static Logger logger = Logger.getLogger(ImporterHandlerA.class);
+    private static final Logger logger = Logger.getLogger(ImporterHandlerA.class);
 
     public static final String IMPORT_HANDLER_ATTR = "import-handler";
 
-    public static String SESSION_IMPORTER="SI";
-    public static String XAR_IMPORTER="XAR";
-    public static String GRADUAL_DICOM_IMPORTER="gradual-DICOM";
-    public static String DICOM_ZIP_IMPORTER="DICOM-zip";
-    public static String BLANK_PREARCHIVE_ENTRY="blank";
+    public static final String SESSION_IMPORTER="SI";
+    public static final String XAR_IMPORTER="XAR";
+    public static final String GRADUAL_DICOM_IMPORTER="gradual-DICOM";
+    public static final String DICOM_ZIP_IMPORTER="DICOM-zip";
+    public static final String BLANK_PREARCHIVE_ENTRY="blank";
 
     static String DEFAULT_HANDLER=SESSION_IMPORTER;
-    final static Map<String,Class<? extends ImporterHandlerA>> IMPORTERS=new HashMap<String,Class<? extends ImporterHandlerA>>();
+    final static Map<String,Class<? extends ImporterHandlerA>> IMPORTERS= new HashMap<>();
 
     private static final String PROP_OBJECT_IDENTIFIER = "org.nrg.import.handler.impl";
     private static final String IMPORTER_PROPERTIES = "importer.properties";