some charges/allowance changes

library/src/main/java/org/mustangproject/Allowance.java

@@ -0,0 +1,16 @@
+package org.mustangproject;
+
+import org.mustangproject.ZUGFeRD.IZUGFeRDAllowanceCharge;
+
+import java.math.BigDecimal;
+
+public class Allowance extends Charge implements IZUGFeRDAllowanceCharge {
+
+	public Allowance() {
+
+	}
+	public Allowance(BigDecimal totalAmount, BigDecimal taxPercent, String reason, String categoryCode) {
+		super(totalAmount, taxPercent, reason, categoryCode);
+
+	}
+}

library/src/main/java/org/mustangproject/Charge.java

@@ -0,0 +1,74 @@
+package org.mustangproject;
+
+import org.mustangproject.ZUGFeRD.IZUGFeRDAllowanceCharge;
+import org.mustangproject.ZUGFeRD.IZUGFeRDExportableProduct;
+
+import java.math.BigDecimal;
+
+public class Charge implements IZUGFeRDAllowanceCharge {
+
+	protected BigDecimal percent;
+	protected BigDecimal totalAmount;
+	protected BigDecimal taxPercent;
+	protected String reason;
+	protected String categoryCode;
+
+	public Charge() {
+
+	}
+
+	public Charge(BigDecimal totalAmount, BigDecimal taxPercent, String reason, String categoryCode) {
+		this.totalAmount = totalAmount;
+		this.taxPercent = taxPercent;
+		this.reason = reason;
+		this.categoryCode = categoryCode;
+	}
+
+
+	public Charge setTotalAmount(BigDecimal totalAmount) {
+		this.totalAmount = totalAmount;
+		return this;
+	}
+
+	public Charge setPercent(BigDecimal percent) {
+		this.percent = percent;
+		return this;
+	}
+
+	public Charge setTaxPercent(BigDecimal taxPercent) {
+		this.taxPercent = taxPercent;
+		return this;
+	}
+
+	public Charge setReason(String reason) {
+		this.reason = reason;
+		return this;
+	}
+
+	public Charge setCategoryCode(String categoryCode) {
+		this.categoryCode = categoryCode;
+		return this;
+	}
+
+
+	@Override
+	public BigDecimal getTotalAmount() {
+		return totalAmount;
+	}
+
+	@Override
+	public String getReason() {
+		return reason;
+	}
+
+	@Override
+	public BigDecimal getTaxPercent() {
+		return taxPercent;
+	}
+
+	@Override
+	public String getCategoryCode() {
+		return categoryCode;
+	}
+
+}

library/src/main/java/org/mustangproject/Invoice.java

@@ -402,6 +402,22 @@ public class Invoice implements IExportableTransaction {
 	}
 
 
+
+	public Invoice addCharge(IZUGFeRDAllowanceCharge charge) {
+		//@todo
+		return this;
+	}
+
+	public Invoice addAllowance(IZUGFeRDAllowanceCharge allowance) {
+		//@todo
+		return this;
+	}
+
+
+	/***
+	 * checks if all required items are set in order to be able to export it
+	 * @return
+	 */
 	public boolean isValid() {
 		return (dueDate != null) && (ownZIP != null) && (ownStreet != null) && (ownLocation != null) && (ownCountry != null) && (ownTaxID != null) && (ownVATID != null) && (recipient != null);
 		//contact

library/src/main/java/org/mustangproject/Item.java

@@ -25,6 +25,16 @@ public class Item implements IZUGFeRDExportableItem {
 		return this;
 	}
 
+	public Item addCharge(IZUGFeRDAllowanceCharge charge) {
+		//@todo
+		return this;
+	}
+
+	public Item addAllowance(IZUGFeRDAllowanceCharge allowance) {
+		//@todo
+		return this;
+	}
+
 	public BigDecimal getGrossPrice() {
 		return grossPrice;
 	}