Fixed #53: error "cropName must be a String" reported when null is provided

src/main/java/org/genesys2/server/service/impl/BatchRESTServiceImpl.java

@@ -559,10 +559,6 @@ public class BatchRESTServiceImpl implements BatchRESTService {
 
 	private boolean updateCrop(Accession accession, JsonNode value) throws RESTApiDataTypeException {
 		if (value != null) {
-			if (!value.isTextual()) {
-				throw new RESTApiDataTypeException("cropName must be a String");
-			}
-
 			if (value.isNull()) {
 				if (!StringUtils.equals(null, accession.getCropName())) {
 					accession.setCropName(null);
@@ -571,6 +567,10 @@ public class BatchRESTServiceImpl implements BatchRESTService {
 				}
 			}
 
+			if (!value.isTextual()) {
+				throw new RESTApiDataTypeException("cropName must be a String");
+			}
+
 			final String cropName = value.textValue().trim();
 			if (!StringUtils.equals(cropName, accession.getCropName())) {
 				accession.setCropName(cropName);