import java.util.*;

public class Group {
  private int id;
  private String name;
  private Set stories;

  public Group(){
  }

  public Group(String name) {
    this.name = name;
  }

  public void setId(int i) {
    id = i;
  }

  public int getId() {
    return id;
  }

  public void setName(String n) {
    name = n;
  }

  public String getName() {
    return name;
  }

  public void setStories(Set l) {
    stories = l;
  }

  public Set getStories() {
    return stories;
  }
}

import java.util.*;

public class Story {
  private int id;
  private String info;
  private Group parent;
  
  public void setParent(Group g) {
    parent = g;
  }
  public Group getParent() {
    return parent;
  }
  public Story(){
  }

  public Story(String info) {
    this.info = info;
  }

  public void setId(int i) {
    id = i;
  }

  public int getId() {
    return id;
  }

  public void setInfo(String n) {
    info = n;
  }

  public String getInfo() {
    return info;
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping 
    PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
    <class name="Group" table="grouptable">
        <id name="id" unsaved-value="0">
             <generator class="increment"/>
        </id>
    
        <set name="stories" cascade="all" inverse="true">
             <key column="parent_id"/>
             <one-to-many class="Story"/>
        </set>
        <property name="name" type="string"/>
    </class>
    
    <class name="Story" table="story">
        <id name="id" unsaved-value="0">
             <generator class="increment"/>
        </id>
        <property name="info"/>
        <many-to-one name="parent" column="parent_id" not-null="true"/>
    </class>
</hibernate-mapping>