OZG-7144 timestamp null safe cause of NPE in Test

src/main/java/de/ozgcloud/eingang/intelliform/DepositDataMapper.java

@@ -26,7 +26,9 @@ package de.ozgcloud.eingang.intelliform;
 import static java.util.stream.Collectors.*;
 
 import java.io.IOException;
+import java.time.ZonedDateTime;
 import java.util.Collection;
+import java.util.GregorianCalendar;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -37,6 +39,7 @@ import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
 
+import javax.xml.datatype.XMLGregorianCalendar;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
@@ -190,7 +193,8 @@ class DepositDataMapper {
 	}
 
 	IntelliFormMetaData buildMetaData(DepositData depositData) {
-		var builder = IntelliFormMetaData.builder().origin(depositData.getTimestamp().toGregorianCalendar().toZonedDateTime());
+		var builder = IntelliFormMetaData.builder();
+		getOrigin(depositData).ifPresent(builder::origin);
 
 		depositData.getCustomParameters()
 				.forEach(entry -> builder.customParameter(IntelliFormMetaData.CUSTOM_PARAM_PREFIX + entry.key.toUpperCase(), entry.value));
@@ -198,4 +202,8 @@ class DepositDataMapper {
 		return builder.build();
 	}
 
+	Optional<ZonedDateTime> getOrigin(DepositData depositData) {
+		return Optional.ofNullable(depositData.getTimestamp()).map(XMLGregorianCalendar::toGregorianCalendar).map(GregorianCalendar::toZonedDateTime);
+	}
+
 }