Java5 Enum and Hessian

[michmill]

I have the following enum and class defined (on both sides of my remote interface):

***
Currency.java
***
public enum Currency implements Serializable {
US_DOLLAR,
CANADIAN_DOLLAR
}

***
Money.java
***
public class Money implements Serializable {
private Currency currency;

public Currency getCurrency() {
return currency;
}
public void setCurrency(Currency currency) {
this.currency = currency;
}
}



When I call a remote method (Hessian), I get the following stacktrace:

<Sep 25, 2006 1:47:58 PM PDT> <Error> <HTTP> <BEA-101017> <weblogic.servlet.internal.WebAppServletContext@13 83279 -
appName: '_appsdir_subscription_war',
name: 'subscription.war', context-path: '/subscription']
Root cause of ServletException.
java.io.IOException: java.lang.InstantiationException:
subscription.common.Currency
at com.caucho.hessian.io.JavaDeserializer.readMap
(JavaDeserializer.java:119)
at com.caucho.hessian.io.HessianInput.readObject
(HessianInput.java:662)
at com.caucho.hessian.io.JavaDeserializer.readMap
(JavaDeserializer.java:135)
at com.caucho.hessian.io.JavaDeserializer.readMap
(JavaDeserializer.java:114)
at com.caucho.hessian.io.HessianInput.readObject
(HessianInput.java:662)


I'm using Java5, weblogic 9.2 and spring 2.0-rc3. Anyone have an idea on why this is happening?

-mike

[michmill]

I was able to work around the problem by changing to use HttpInvoker instead of Hessian. It seems Hessian doesn't know how to work with Java 5 enums. I don't know if any of the other remoting services have the same problem, because HttpInvoker was going to be my second choice anyway.

[pgras]

Not really an answer to your question, but you could also use

java.util.Currency

for your Money pattern.

-Patrick

[michmill]

Yeah, that was just the easiest example I could come up with. There are several other enums I could have used, I just wanted something that was simple to explain. Thanks.

[pgras]

Hello,

I don't know the version of Hessian in Spring2.0-rc3, in rc4 it is 3.0.20. The enums should be supported since Hessian 3.0.20...

http://bugs.caucho.com/view.php?id=1209

-Patrick

[michmill]

Good call pgras. Spring 2.0 was just released in final version yesterday, and it comes with Hessian 3.0.20, which solves the enum problem. Thanks for the heads up.

-m