diff --git a/java/org/slub/rosetta/dps/repository/plugin/SLUBXmlFormatValidationPlugin.java b/java/org/slub/rosetta/dps/repository/plugin/SLUBXmlFormatValidationPlugin.java
index 819906330a715b5aa9e62afebcf793ebd3b7138a..fd3e46c87228012b4a8865614c65d6474182e0c6 100644
--- a/java/org/slub/rosetta/dps/repository/plugin/SLUBXmlFormatValidationPlugin.java
+++ b/java/org/slub/rosetta/dps/repository/plugin/SLUBXmlFormatValidationPlugin.java
@@ -348,25 +348,26 @@ public class SLUBXmlFormatValidationPlugin implements FormatValidationPlugin {
         reportDetail("assigned schema uri: " + validationSchema.schemaURI);
         var schemaType = validationSchema.schemaType;
         Document doc = getDocument(filePath);
-        if (schemaType == ValidationSchemaType.dtd) {
-            SLUBValidateDTD validator = new SLUBValidateDTD( validationCatalogResolver, validationErrorHandler );
-            valid = validator.validateAgainst(filePath);
-        }
-        else if (schemaType == ValidationSchemaType.relaxng) {
-            SLUBValidateRelaxNG validator = new SLUBValidateRelaxNG( );
-            valid = validator.validateAgainst(doc, validationSchema.schemaURI);
-
-        } else if (schemaType == ValidationSchemaType.schematron) {
-            SLUBValidateSchematron validator = new SLUBValidateSchematron(  );
-            valid = validator.validateAgainst(doc, validationSchema.schemaURI);
-            reportError("unsupported schematron schema uri="+ validationSchema.schemaURI + " of type: " + validationSchema.schemaType);
-            valid = false;
-            /*  */
-        } else if (schemaType == ValidationSchemaType.schema) {
-            validateFormatAgainstSchemaRecursively(doc, validationSchema);
-        } else {
-            reportError("unsupported schema uri="+ validationSchema.schemaURI + " of type: " + validationSchema.schemaType);
-            valid = false;
+        switch (schemaType) {
+            case dtd -> {
+                SLUBValidateDTD validator = new SLUBValidateDTD(validationCatalogResolver, validationErrorHandler);
+                valid = validator.validateAgainst(filePath);
+            }
+            case schema -> validateFormatAgainstSchemaRecursively(doc, validationSchema);
+            case relaxng -> {
+                SLUBValidateRelaxNG validator = new SLUBValidateRelaxNG();
+                valid = validator.validateAgainst(doc, validationSchema.schemaURI);
+            }
+            case schematron -> {
+                SLUBValidateSchematron validator = new SLUBValidateSchematron();
+                valid = validator.validateAgainst(doc, validationSchema.schemaURI);
+                reportError("unsupported schematron schema uri=" + validationSchema.schemaURI + " of type: " + validationSchema.schemaType);
+                valid = false;
+            }
+            default -> {
+                reportError("unsupported schema uri=" + validationSchema.schemaURI + " of type: " + validationSchema.schemaType);
+                valid = false;
+            }
         }
     }
 
@@ -409,10 +410,8 @@ public class SLUBXmlFormatValidationPlugin implements FormatValidationPlugin {
         //dbf.setXIncludeAware(true);
         dbf.setNamespaceAware(true);
         DocumentBuilder db = dbf.newDocumentBuilder();
-
         db.setErrorHandler( validationErrorHandler );
         //db.setEntityResolver(validationCatalogResolver);
-
         if (debug) System.out.println(
                 "DOCUMENT LOADER: ns aware=" + db.isNamespaceAware()
                 + " include aware=" + db.isXIncludeAware()