package org.itracker.persistence.dao;
   
   import java.sql.PreparedStatement;
   import java.sql.ResultSet;
   import java.sql.SQLException;
   import java.sql.Types;
   import java.util.Properties;
   
   import org.hibernate.HibernateException;
  
  /**
   * Custom Hibernate UserType to persist a Java 5 enum constant as an INTEGER
   * using its ordinal position. 
   * 
   * <p>Beware that the enum.ordinal() returns a is zero based that changes 
   * if the position of the enum members change! </p>
   * 
   * @author johnny
   */
  public final class EnumOrdinalUserType extends AbstractEnumUserType {
      
      private static final int[] SQL_TYPES = { Types.SMALLINT };
      
      /** Enum members, in the order they where declared. */
      @SuppressWarnings("unchecked")
  	private Enum[] enumValues;
      
      /** 
       * Default constructor, required by Hibernate. 
       */
      public EnumOrdinalUserType() {
      }
  
      public void setParameterValues(Properties parameters) {
          super.setParameterValues(parameters);
          this.enumValues = this.enumClass.getEnumConstants();
      }
  
      public Object nullSafeGet(ResultSet rs, String[] names,
              Object owner) throws HibernateException, SQLException {
          final int ordinal = rs.getInt(names[0]);
          
          return rs.wasNull() ? null : this.enumValues[ordinal];
      }
  
      public void nullSafeSet(PreparedStatement stmt, Object value,
              int index) throws HibernateException, SQLException {
          if (value == null) {
              stmt.setNull(index, Types.INTEGER);
          } else {
              stmt.setInt(index, ((Enum<?>) value).ordinal());
          }
      }
  
      public int[] sqlTypes() {
          return SQL_TYPES;
      }
  
      public String objectToSQLString(Object value) {
          return Integer.toString(((Enum<?>) value).ordinal());
      }
      
      public String toXMLString(Object value) {
          return objectToSQLString(value);
      }
      
      public Object fromXMLString(String xmlValue) {
          final int ordinal;
          
          try {
              ordinal = Integer.parseInt(xmlValue);
          } catch (NumberFormatException ex) {
              throw new HibernateException(ex);
          }
          return this.enumValues[ordinal];
      }
      
  }