Is it possible to persist an enumerated object as a string

Question

I created a java object for an enumerated type (greatly simplified for this
discussion):
public class Role implements java.io.Serializable {
public Role() {
private Role(String role) {
this.role = role;
public String toString() {
return role;
public String getRole() {
return role;
private String role;
public static final Role GUEST = new Role("GUEST");
public static final Role REGISTERED_USER = new Role("REGISTERED_USER");
public static final Role TRIAL_USER = new Role("TRIAL_USER");
The problem is it's persisted as a first class entity. That means in the
CustomerType table I get hundreds of them, one for each relation. The
solution for that is to use JDO to get an existing CustomerType from the
datastore as use it for assignments instead of just using the class itself.
But I'm curious, are there extensions that would allow me to map
CustomerType to a string column in a table? For example, a Customer has a
CustomerType. Can CustomerType map to a string column in the Customer
table? Is this possible? I think this would be really cool, because then I
can say:
Customer c = new Customer();
c.setCustomerType(CustomerType.GUEST);
without having to retrieve the CustomerType.GUEST from the datastore.
Michael

Answer 1

Michael-
Also note that Kodo 2.5.0 introduces a StirngifiedMapping, which enables
simple persisting of things like enumerations (and anything else that
can be round-tripped via stringification).
Take a look at samples/scoStringification/ in the 2.5.0 release.
In article <[email protected]>, Michael Mattox wrote:
I found a solution to this, although from a different approach. Earlier I
said a Customer has a CustomerType. I changed that relation to say a
Customer has a String called customerType. Then I changed the
getter/setters to use the CustomerType. This gives me the advantage of
using an enumerated type with the ability to store a simple String in the
database.
So far this approach is working well. If you have any comments let me know.
Michael
"Michael Mattox" <[email protected]> wrote in message
news:[email protected]...
I created a java object for an enumerated type (greatly simplified forthis
discussion):
public class Role implements java.io.Serializable {
public Role() {
private Role(String role) {
this.role = role;
public String toString() {
return role;
public String getRole() {
return role;
private String role;
public static final Role GUEST = new Role("GUEST");
public static final Role REGISTERED_USER = new Role("REGISTERED_USER");
public static final Role TRIAL_USER = new Role("TRIAL_USER");
The problem is it's persisted as a first class entity. That means in the
CustomerType table I get hundreds of them, one for each relation. The
solution for that is to use JDO to get an existing CustomerType from the
datastore as use it for assignments instead of just using the classitself.
But I'm curious, are there extensions that would allow me to map
CustomerType to a string column in a table? For example, a Customer has a
CustomerType. Can CustomerType map to a string column in the Customer
table? Is this possible? I think this would be really cool, because thenI
can say:
Customer c = new Customer();
c.setCustomerType(CustomerType.GUEST);
without having to retrieve the CustomerType.GUEST from the datastore.
Michael
Marc Prud'hommeaux [email protected]
SolarMetric Inc. http://www.solarmetric.com