Skip to main content
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [ecf-dev] ECF not serializing changed method arguments (generic server) 
Hi Konrad,

On 4/12/2012 11:38 AM, Konrad Bielak wrote:

Hello,

Suppose `person` is an ECF proxy object implementing Person interface
with getPerson() method. getPerson() has some parameters, and these
parameters are Holder [1] class (which means there is another object
reference inside).

Now, consider following Consumer endpoint code:

  Holder<String>  personId = new Holder<String>("Person from OSGi bundle");
  Holder<String>  ssn = new Holder<String>("1");
  Holder<String>  name = new Holder<String>("1");

  logger.info("--->  SENDING data: personId=" + personId.value + "
ssn=" + ssn.value + " name=" + name.value);
  person.getPerson(personId, ssn, name);
  logger.info("<--- Returned data: personId=" + personId.value + "
ssn=" + ssn.value + " name=" + name.value);

on Provider endpoint on another OSGi container `ssn` and `name` inside
values are changed. But consumer wont know about this, because ECF
does not serialize these objects again when returning from method
getPerson(). Log:
--->  SENDING data: personId=Person from OSGi bundle ssn=1 name=1
<--- Returned data: personId=Person from OSGi bundle ssn=1 name=1

Is there any way to serialize these objects again on Provider endpoint?
Well...if I'm understanding you correctly, then you could implement Person.getPerson(String,String,String) like this: 

public Person getPerson(String personId, String ssn, String value) {
      return new SerializablePerson(personId,ssn,value);
}
And assuming that Person was Serializable, then I think this would do what you want to do.
But this seems a little unnatural to me...so have you considered that rather than trying to reference the members in Person (person.ssn, person.name, etc)...it might be simpler/clearer to have a structure where the top-level service interface was something like: 

// This is the (remote) service interface
public interface PersonManager {

public Person getPerson(String personId);
public Person createPerson(String personId, String ssn, String name);
etc.

}

with the Person param being...

public class Person implements Serializable {

private String id;
private String ssn;
private String name;

public Person(String id, String ssn, String name) {
   this.id = id;
   this.ssn = ssn;
   this.value = name;
}

public String getId() {
   return id;
}

public String getSSN() {
   return ssn;
}

public String getName() {
}
   return name;
}

And then consumers of the PersonManager remote service would call:

Person person = person.createPerson("1","333-33-3333","howdy");
// work with Person fields locally
// However...host (db?) instance of Person changes (by some other usage, etc), then
// the remote service consumer would need to get a refresh:
updatedPerson = personManager.getPerson(newPerson.getId());

If...alternatively...you are asking if there is some way that the local values of Person (id, ssn, value) could be updated *automatically* on the remote service consumer process when they change on the host process...then the answer is 'no'...unless you are using a remoting system that supports pass-by-reference rather than pass-by value.  Most remoting systems these days only do pass-by-value...since pass-by-reference has lots of complications (e.g. garbage collection, failure handling, remote references, etc) that are extremely thorny.  None of the current ECF providers...except the RMI provider...do only pass-by-value.  And all the REST-based approaches, etc are all pass-by-value.

<stuff deleted>

BTW Pax-Runner script for ECF4Felix [2] is outdated.

 [1] http://docs.oracle.com/javase/6/docs/api/javax/xml/ws/Holder.html
 [2] https://github.com/ECF/ECF4Felix

[Scott]  Ok...Markus would be able to take a look at updating this?

Thanks,

Scott

Back to the top