Hi Guys I am getting a class cast exception when trying to create a simple one to many relationship. I have included the stack trace, the code that is causing it, the configuration file and the persistent object. What am I doing wrong?

hibernate 3.1

/*
* Created on 2 Sep 2007
*
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*/
package com.hibernate.skylite;

import java.util.HashSet;
import java.util.Set;

public class OrderDetails {

private int orderDetailsID;
private String address;
private String lengthOfService;
private String makeOfBox;
private String name;
private String postCode;
private String typeOfBox;
private String typeOfPayment;
private String salesPersonName;
private String charity;
private String existingFaults;
private String price;
private String telephoneNumber;
private String mobileNumber;
private String agreementID;
private String notes;
private String date;

private Set creditCards;
private Set directDebits;

public Set getDirectDebits() {
return directDebits;
}

public void setDirectDebits(Set directDebits) {
this.directDebits = directDebits;
}

public OrderDetails(){

}

public String getAddress() {
return address;
}

public void setAddress(String address) {
this.address = address;
}

public String getAgreementID() {
return agreementID;
}

public void setAgreementID(String agreementID) {
this.agreementID = agreementID;
}

public String getCharity() {
return charity;
}

public void setCharity(String charity) {
this.charity = charity;
}

public String getDate() {
return date;
}

public void setDate(String date) {
this.date = date;
}

public String getExistingFaults() {
return existingFaults;
}

public void setExistingFaults(String existingFaults) {
this.existingFaults = existingFaults;
}

public String getLengthOfService() {
return lengthOfService;
}

public void setLengthOfService(String lengthOfService) {
this.lengthOfService = lengthOfService;
}

public String getMakeOfBox() {
return makeOfBox;
}

public void setMakeOfBox(String makeOfBox) {
this.makeOfBox = makeOfBox;
}

public String getMobileNumber() {
return mobileNumber;
}

public void setMobileNumber(String mobileNumber) {
this.mobileNumber = mobileNumber;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getNotes() {
return notes;
}

public void setNotes(String notes) {
this.notes = notes;
}

public int getOrderDetailsID() {
return orderDetailsID;
}

public void setOrderDetailsID(int orderDetailsID) {
this.orderDetailsID = orderDetailsID;
}

public String getPostCode() {
return postCode;
}

public void setPostCode(String postCode) {
this.postCode = postCode;
}

public String getPrice() {
return price;
}

public void setPrice(String price) {
this.price = price;
}

public String getSalesPersonName() {
return salesPersonName;
}

public void setSalesPersonName(String salesPersonName) {
this.salesPersonName = salesPersonName;
}

public String getTelephoneNumber() {
return telephoneNumber;
}

public void setTelephoneNumber(String telephoneNumber) {
this.telephoneNumber = telephoneNumber;
}

public String getTypeOfBox() {
return typeOfBox;
}

public void setTypeOfBox(String typeOfBox) {
this.typeOfBox = typeOfBox;
}

public String getTypeOfPayment() {
return typeOfPayment;
}

public void setTypeOfPayment(String typeOfPayment) {
this.typeOfPayment = typeOfPayment;
}

public Set getCreditCards() {
return creditCards;
}

public void setCreditCards(CardDetails creditCards) {
this.creditCards.add(creditCards);

}



}


<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>
<class name="com.hibernate.skylite.OrderDetails"
table="orderdetails">
<id name="orderDetailsID" column="orderDetailsID" type="java.lang.Integer">
<generator class="increment"/>
</id>
<property name="address" column="address" type="java.lang.String"/>
<property name="lengthOfService" column="sortcode" type="java.lang.String"/>
<property name="makeOfBox" column="makeOfBox" type="java.lang.String"/>
<property name="name" column="name" type="java.lang.String"/>
<property name="postCode" column="postCode" type="java.lang.String"/>
<property name="typeOfBox" column="typeOfBox" type="java.lang.String"/>
<property name="typeOfPayment" column="typeOfPayment" type="java.lang.String"/>
<property name="salesPersonName" column="salesPersonName" type="java.lang.String"/>
<property name="charity" column="charity" type="java.lang.String"/>
<property name="existingFaults" column="existingFaults" type="java.lang.String"/>
<property name="price" column="price" type="java.lang.Integer"/>
<property name="telephoneNumber" column="telephoneNumber" type="java.lang.String"/>
<property name="mobileNumber" column="mobileNumber" type="java.lang.Integer"/>
<property name="agreementID" column="agreementID" type="java.lang.String"/>
<property name="notes" column="notes" type="java.lang.String"/>
<property name="date" column="date" type="java.lang.String"/>

<set name="creditCards" table="cardpayment" lazy="true" cascade="all" inverse="true">
<key column="creditCardID"></key>
<one-to-many class="com.hibernate.skylite.CardDetails"/>
</set>

<set name="directDebits" table="directdebit" lazy="true" cascade="all" inverse="true">
<key column="directDebitID"></key>
<one-to-many class="com.hibernate.skylite.DirectDebitDetails"/>
</set>
</class>
</hibernate-mapping>

Session session = HibernateSessionFactory.getSession();
Transaction tx = session.beginTransaction();

OrderDetails od = new OrderDetails();
od.setAddress("Hello");

session.save(od);
tx.commit();

session.close();

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
%%%% Error Creating SessionFactory %%%%
java.lang.ClassCastException: org.hibernate.mapping.Set
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1041)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1168)
at com.hibernate.skylite.HibernateSessionFactory.rebuildSessionFactory(HibernateSessionFactory.java:60)
at com.hibernate.skylite.HibernateSessionFactory.getSession(HibernateSessionFactory.java:43)
at com.hibernate.skylite.TestClass.main(TestClass.java:19)
Exception in thread "main" java.lang.NullPointerException
at com.hibernate.skylite.TestClass.main(TestClass.java:20)


Name and version of the database you are using:MySQL

Not sure if this is the root of your problem, but I'd think your one-to-many mappings are incomplete. You probably need to specify a column and name property for each at the least.