Class
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package par.common;

import java.util.Collection;
import java.util.Collections;
import java.util.LinkedList;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Persistence;

@Entity
public class SampleA {

   @Id @GeneratedValue(strategy=GenerationType.IDENTITY)
   private int id;
   
   private String name;
   
   @OneToMany(mappedBy="parent", cascade=CascadeType.ALL)
   private Collection<SampleA> collection = new LinkedList<SampleA>();

   @ManyToOne
   private SampleA parent;
   
   
   public Collection<SampleA> getCollection() {
      return collection;
   }

   public void setCollection(Collection<SampleA> collection) {
      this.collection = collection;
   }

   public int getId() {
      return id;
   }

   public void setId(int id) {
      this.id = id;
   }

   public String getName() {
      return name;
   }

   public void setName(String name) {
      this.name = name;
   }
   
   public void addChild(SampleA c) {
      c.parent = this;
      collection.add(c);
   }
      
}