How to use set , get in gwt shared folder - gwt

Question

I have a class select in gwt shared folder with some set and get function like..
public class Select implements Serializable {
private static final long serialVersionUID = 1L;
String userid=null;
String name=null;
/******************Set********************/
public void setId(String userid) {
this.userid=userid;
}
public void setName(String name) {
this.name=name;
}
/******************get*************************/
public String getId() {
return userid;
}
public String getName() {
return name;
}
now I called setid() and getid() from server,its working . but when i am calling getid() from client, its returning me a null value please some one help me ...
my client side code is ...
greetingService.select(new AsyncCallback<String>()
{
Select sel=new Select();
public void onSuccess(String result) {
System.out.println("client..id"+sel.getId());
});

Answer 1

sel.getid() is returning null because its not being set by anything. You are simply calling new Select() and creating a new Select object on the client. If you want to retrieve the Select object with data in it form the server you need to pass it as the result parameter of the AsyncCallback callback via an RPC service, like so:
greetingService.select(new AsyncCallback<Select>() {
public void onSuccess(Select result) {
// Do what you want with the Select object returned via server
}
public void onFailure(Throwable caught) {
System.out.println("Call failed " + caught.getMessage());
}
});
Assuming you have set up the RPC service properly, you will handle the server end as a regular method:
public class GreetingServiceImpl extends RemoteServiceServletImpl {
public Select select() {
Select select = new Select();
select.setId(1);
return select;
}
}
You may find this tutorial helpful http://www.gwtproject.org/doc/latest/tutorial/RPC.html