package ejava.examples.orm.inheritance.annotated;
   
   import javax.persistence.*;
   
   /**
    * This class provides a base class for table-per-class inheritance strategy
    * example. The derived classes will squash the information from this entity
    * within their tables.<p/>
    * 
   * Note too that since there is no physical base table, something external 
   * must be used to create id values or allow the ids of each sub-type to 
   * be allowed to be locally generated (thus getting overlaps in id values).
   * The approach taken here was to define a sequence generator.
   */
  @Entity
  @Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
  @SequenceGenerator(
          name="orminhSeq", //required logical name
          sequenceName="ORMINH_SEQ" //name in database
  )
  public abstract class Account {
      @Id @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="orminhSeq")
      private long id;
      private double balance;
      
      public Account() {}
      public Account(long id) { this.id=id; }
      public long getId() { return id; }
      
      public double getBalance() { return balance; }
      public void setBalance(double balance) {
          this.balance = balance;
      }
      
      public void deposit(double amount) throws AccountException {
          setBalance(getBalance() + amount);
      }
      public abstract void withdraw(double amount) throws AccountException;
      public void processInterest() {}
      
      public String toString() {
          StringBuilder text = new StringBuilder(super.toString());
          text.append(", id=" + id);
          text.append(", balance=" + balance);
          return text.toString();
      }
  }