switched IZUGFeRDExportableContact to default-Methods; added

ShipToTradeParty: if the merchandies is not shipped to the same address
as stated in the invoide; added BuyerOrderReferencedDocument: the ID of
the purchase order the invoice ist based on

src/main/java/org/mustangproject/ZUGFeRD/IZUGFeRDExportableContact.java

@@ -44,7 +44,9 @@ public interface IZUGFeRDExportableContact {
 	 *
 	 * @return First and last name of the recipient
 	 */
-	String getName();
+	default String getName() {
+		return null;
+	}
 
 
 	/**
@@ -52,7 +54,9 @@ public interface IZUGFeRDExportableContact {
 	 *
 	 * @return Postal code of the recipient
 	 */
-	String getZIP();
+	default String getZIP() {
+		return null;
+	}
 
 
 	/**
@@ -60,7 +64,9 @@ public interface IZUGFeRDExportableContact {
 	 *
 	 * @return VAT ID (Umsatzsteueridentifikationsnummer) of the contact
 	 */
-	String getVATID();
+	default String getVATID() {
+		return null;
+	}
 
 
 	/**
@@ -68,7 +74,9 @@ public interface IZUGFeRDExportableContact {
 	 *
 	 * @return two-letter iso country code of the contact
 	 */
-	String getCountry();
+	default String getCountry() {
+		return null;
+	}
 
 
 	/**
@@ -76,7 +84,9 @@ public interface IZUGFeRDExportableContact {
 	 *
 	 * @return Returns the city of the recipient
 	 */
-	String getLocation();
+	default String getLocation() {
+		return null;
+	}
 
 
 	/**
@@ -84,6 +94,8 @@ public interface IZUGFeRDExportableContact {
 	 *
 	 * @return street address (street+number) of the contact
 	 */
-	String getStreet();
+	default String getStreet() {
+		return null;
+	}
 
 }

src/main/java/org/mustangproject/ZUGFeRD/IZUGFeRDExportableTransaction.java

@@ -27,10 +27,10 @@ package org.mustangproject.ZUGFeRD;
  * */
 
 
-import org.mustangproject.ZUGFeRD.model.DocumentCodeTypeConstants;
-
 import java.util.Date;
 
+import org.mustangproject.ZUGFeRD.model.DocumentCodeTypeConstants;
+
 public interface IZUGFeRDExportableTransaction {
 
 	/**
@@ -42,6 +42,7 @@ public interface IZUGFeRDExportableTransaction {
 		return DocumentCodeTypeConstants.INVOICE;
 	}
 
+
 	/**
 	 * Number, typically invoice number of the invoice
 	 *
@@ -281,4 +282,74 @@ public interface IZUGFeRDExportableTransaction {
 		return null;
 	}
 
+
+	/**
+	 * get reference number of the purchase order this invoice is based on
+	 *
+	 * @return the ID of the purchase order this document refers to
+	 */
+	default String getOrderReferenceNumber() {
+		return null;
+	}
+
+
+	/**
+	 * consignee identification (identification of the organisation the goods are shipped to [assigned by the costumer])
+	 *
+	 * @return the sender's identification
+	 */
+	default String getShipToOrganisationID() {
+		return null;
+	}
+
+
+	/**
+	 * consignee name (name of the organisation the goods are shipped to)
+	 *
+	 * @return the consignee's organisation name
+	 */
+	default String getShipToOrganisationName() {
+		return null;
+	}
+
+
+	/**
+	 * consignee street address (street of the organisation the goods are shipped to)
+	 *
+	 * @return consignee street address
+	 */
+	default String getShipToStreet() {
+		return null;
+	}
+
+
+	/**
+	 * consignee street postal code (postal code of the organisation the goods are shipped to)
+	 *
+	 * @return consignee postal code
+	 */
+	default String getShipToZIP() {
+		return null;
+	}
+
+
+	/**
+	 * consignee city (city of the organisation the goods are shipped to)
+	 *
+	 * @return the consignee's city
+	 */
+	default String getShipToLocation() {
+		return null;
+	}
+
+
+	/**
+	 * consignee two digit country code (country code of the organisation the goods are shipped to)
+	 *
+	 * @return the consignee's two character country iso code
+	 */
+	default String getShipToCountry() {
+		return null;
+	}
+
 }

src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDTransactionModelConverter.java

@@ -39,7 +39,6 @@ import org.mustangproject.ZUGFeRD.model.CrossIndustryDocumentType;
 import org.mustangproject.ZUGFeRD.model.DateTimeType;
 import org.mustangproject.ZUGFeRD.model.DateTimeTypeConstants;
 import org.mustangproject.ZUGFeRD.model.DocumentCodeType;
-import org.mustangproject.ZUGFeRD.model.DocumentCodeTypeConstants;
 import org.mustangproject.ZUGFeRD.model.DocumentContextParameterType;
 import org.mustangproject.ZUGFeRD.model.DocumentContextParameterTypeConstants;
 import org.mustangproject.ZUGFeRD.model.DocumentLineDocumentType;
@@ -55,6 +54,7 @@ import org.mustangproject.ZUGFeRD.model.PaymentMeansCodeType;
 import org.mustangproject.ZUGFeRD.model.PaymentMeansCodeTypeConstants;
 import org.mustangproject.ZUGFeRD.model.PercentType;
 import org.mustangproject.ZUGFeRD.model.QuantityType;
+import org.mustangproject.ZUGFeRD.model.ReferencedDocumentType;
 import org.mustangproject.ZUGFeRD.model.SupplyChainEventType;
 import org.mustangproject.ZUGFeRD.model.SupplyChainTradeAgreementType;
 import org.mustangproject.ZUGFeRD.model.SupplyChainTradeDeliveryType;
@@ -62,7 +62,6 @@ import org.mustangproject.ZUGFeRD.model.SupplyChainTradeLineItemType;
 import org.mustangproject.ZUGFeRD.model.SupplyChainTradeSettlementType;
 import org.mustangproject.ZUGFeRD.model.SupplyChainTradeTransactionType;
 import org.mustangproject.ZUGFeRD.model.TaxCategoryCodeType;
-import org.mustangproject.ZUGFeRD.model.TaxCategoryCodeTypeConstants;
 import org.mustangproject.ZUGFeRD.model.TaxRegistrationType;
 import org.mustangproject.ZUGFeRD.model.TaxRegistrationTypeConstants;
 import org.mustangproject.ZUGFeRD.model.TaxTypeCodeType;
@@ -201,10 +200,29 @@ class ZUGFeRDTransactionModelConverter {
 		tradeAgreement.setBuyerTradeParty(getBuyer());
 		tradeAgreement.setSellerTradeParty(getSeller());
 
+		if (getBuyerOrderReferencedDocument() != null) {
+			tradeAgreement.getBuyerOrderReferencedDocument().add(getBuyerOrderReferencedDocument());
+		}
+
 		return tradeAgreement;
 	}
 
 
+	private ReferencedDocumentType getBuyerOrderReferencedDocument() {
+		if (trans.getOrderReferenceNumber() == null) {
+			return null;
+		}
+
+		ReferencedDocumentType buyerOrderReferencedDocument = xmlFactory.createReferencedDocumentType();
+
+		IDType orderID = xmlFactory.createIDType();
+		orderID.setValue(trans.getOrderReferenceNumber());
+		buyerOrderReferencedDocument.getID().add(orderID);
+
+		return buyerOrderReferencedDocument;
+	}
+
+
 	private TradePartyType getBuyer() {
 
 		TradePartyType buyerTradeParty = xmlFactory.createTradePartyType();
@@ -308,10 +326,62 @@ class ZUGFeRDTransactionModelConverter {
 	}
 
 
+	/**
+	 * If the ship-to party (e.g. in the case of international transactions) or, in the case of virtual goods, the recipient has to be shown separately on an
+	 * invoice, then this is done by adding the ShipToTradeParty
+	 */
+	private TradePartyType getShipToParty() {
+		if (trans.getShipToOrganisationName() == null) {
+			return null;
+		}
+
+		TradePartyType shipToParty = xmlFactory.createTradePartyType();
+
+		if (trans.getShipToOrganisationID() != null) {
+			IDType sellerID = xmlFactory.createIDType();
+			sellerID.setValue(trans.getShipToOrganisationID());
+			shipToParty.getID().add(sellerID);
+		}
+
+		TextType shipToName = xmlFactory.createTextType();
+		shipToName.setValue(trans.getShipToOrganisationName());
+		shipToParty.setName(shipToName);
+
+		if (trans.getShipToLocation() != null) {
+			TradeAddressType shipToAddressType = xmlFactory
+					.createTradeAddressType();
+			TextType shipToCityName = xmlFactory.createTextType();
+			shipToCityName.setValue(trans.getShipToLocation());
+			shipToAddressType.setCityName(shipToCityName);
+
+			CountryIDType shipToCountryId = xmlFactory.createCountryIDType();
+			shipToCountryId.setValue(trans.getShipToCountry());
+			shipToAddressType.setCountryID(shipToCountryId);
+
+			TextType shipToAddress = xmlFactory.createTextType();
+			shipToAddress.setValue(trans.getShipToStreet());
+			shipToAddressType.setLineOne(shipToAddress);
+
+			CodeType shipToPostcode = xmlFactory.createCodeType();
+			shipToPostcode.setValue(trans.getShipToZIP());
+			shipToAddressType.getPostcodeCode().add(shipToPostcode);
+
+			shipToParty.setPostalTradeAddress(shipToAddressType);
+		}
+
+		return shipToParty;
+	}
+
+
 	private SupplyChainTradeDeliveryType getTradeDelivery() {
 
 		SupplyChainTradeDeliveryType tradeDelivery = xmlFactory
 				.createSupplyChainTradeDeliveryType();
+
+		if (getShipToParty() != null) {
+			tradeDelivery.setShipToTradeParty(getShipToParty());
+		}
+
 		SupplyChainEventType deliveryEvent = xmlFactory
 				.createSupplyChainEventType();
 		DateTimeType deliveryDate = xmlFactory.createDateTimeType();
@@ -916,7 +986,7 @@ class ZUGFeRDTransactionModelConverter {
 	}
 
 
- 	private HashMap<BigDecimal, VATAmount> getVATPercentAmountMap(Boolean itemOnly) {
+	private HashMap<BigDecimal, VATAmount> getVATPercentAmountMap(Boolean itemOnly) {
 		HashMap<BigDecimal, VATAmount> hm = new HashMap<>();
 
 		for (IZUGFeRDExportableItem currentItem : trans.getZFItems()) {
@@ -938,8 +1008,9 @@ class ZUGFeRDTransactionModelConverter {
 				BigDecimal percent = headerAllowance.getTaxPercent();
 				VATAmount itemVATAmount = new VATAmount(
 						headerAllowance.getTotalAmount(), headerAllowance
-						.getTotalAmount().multiply(percent)
+								.getTotalAmount().multiply(percent)
-						.divide(new BigDecimal(100)), trans.getDocumentCode());
+								.divide(new BigDecimal(100)),
+						trans.getDocumentCode());
 				VATAmount current = hm.get(percent);
 				if (current == null) {
 					hm.put(percent, itemVATAmount);
@@ -956,7 +1027,8 @@ class ZUGFeRDTransactionModelConverter {
 				VATAmount itemVATAmount = new VATAmount(
 						logisticsServiceCharge.getTotalAmount(),
 						logisticsServiceCharge.getTotalAmount()
-								.multiply(percent).divide(new BigDecimal(100)), trans.getDocumentCode());
+								.multiply(percent).divide(new BigDecimal(100)),
+						trans.getDocumentCode());
 				VATAmount current = hm.get(percent);
 				if (current == null) {
 					hm.put(percent, itemVATAmount);
@@ -971,7 +1043,8 @@ class ZUGFeRDTransactionModelConverter {
 				BigDecimal percent = charge.getTaxPercent();
 				VATAmount itemVATAmount = new VATAmount(
 						charge.getTotalAmount(), charge.getTotalAmount()
-						.multiply(percent).divide(new BigDecimal(100)), trans.getDocumentCode());
+								.multiply(percent).divide(new BigDecimal(100)),
+						trans.getDocumentCode());
 				VATAmount current = hm.get(percent);
 				if (current == null) {
 					hm.put(percent, itemVATAmount);