Version 3

    UserType for persisting an Enum with a VARCHAR column

    The following code is a 'template' to easy Enum (Java 1.5) mapping.

    See also https://community.jboss.org/wiki/Java5EnumUserType

    import java.io.Serializable; 
    import java.sql.PreparedStatement; 
    import java.sql.ResultSet; 
    import java.sql.SQLException; 
    import java.sql.Types; 
    import org.hibernate.HibernateException; 
    import org.hibernate.usertype.UserType; 
    
    public class EnumUserType<E extends Enum<E>> implements UserType { 
        private Class<E> clazz = null; 
        protected EnumUserType(Class<E> c) { 
            this.clazz = c; 
        } 
     
        private static final int[] SQL_TYPES = {Types.VARCHAR}; 
        public int[] sqlTypes() { 
            return SQL_TYPES; 
        } 
     
        public Class returnedClass() { 
            return clazz; 
        } 
     
        public Object nullSafeGet(ResultSet resultSet, String[] names, Object owner) throws HibernateException, SQLException { 
            String name = resultSet.getString(names[0]); 
            E result = null; 
            if (!resultSet.wasNull()) { 
                result = Enum.valueOf(clazz, name); 
            } 
            return result; 
        } 
     
        public void nullSafeSet(PreparedStatement preparedStatement, Object value, int index) throws HibernateException, SQLException { 
            if (null == value) { 
                preparedStatement.setNull(index, Types.VARCHAR); 
            } else { 
                preparedStatement.setString(index, ((Enum)value).name()); 
            } 
        } 
     
        public Object deepCopy(Object value) throws HibernateException{ 
            return value; 
        } 
     
        public boolean isMutable() { 
            return false; 
        } 
     
        public Object assemble(Serializable cached, Object owner) throws HibernateException  
             return cached;
        } 
    
        public Serializable disassemble(Object value) throws HibernateException { 
            return (Serializable)value; 
        } 
     
        public Object replace(Object original, Object target, Object owner) throws HibernateException { 
            return original; 
        } 
        public int hashCode(Object x) throws HibernateException { 
            return x.hashCode(); 
        } 
        public boolean equals(Object x, Object y) throws HibernateException { 
            if (x == y) 
                return true; 
            if (null == x || null == y) 
                return false; 
            return x.equals(y); 
        } 
    } 

    Now, let's imagine you have the following Enum:

    public enum MyEnum { 
        ENUM_A, 
        ENUM_B; 
    }

    Just create the following custom mapping type:

    public class MyEnumUserType extends EnumUserType<MyEnum> { 
        public MyEnumUserType() {
            super(MyEnum.class);
        }
    }

    And finally, in your mapping file:

    <hibernate-mapping>
    [...]
      <property name="sample" type="mypackage.MyEnumUserType" not-null="true"/>
    [...]

    Vincent