I am developing my first Seam + Android application and I am facing some new scenarios as expected.
Now specifically for this app, I decided not to keep any state because probably 80% to 90% of the server calls on the REST service will be specifically to do a simple synchronization and the client is gone for a while, so there is(probably) no point on keeping any state on the server side for these calls.
Well there is a specific routine where I need to persist an Object sent by device to the server side and this object is bind to a specific user(a very common scenario in my opinion).
So there goes some code to ilustrate.
The Home interface has a user injected by Seam:
@Name("pesoHome")
public class PesoHome extends EntityHome<Peso> {
private static final long serialVersionUID = 6087763635317971234L;
@In
User user;
Than we need a rest service wich uses this home interface:
public class PesoRest{
@Logger
Log log;
开发者_如何学运维@In(create = true)
UserPesquisa userPesquisa;
@In(create = true)
PesoHome pesoHome;
@POST
@Path("/cadastrar/{userEmail}")
@Consumes(MediaType.APPLICATION_JSON)
public Response cadastraPeso(@PathParam("userEmail") String email, String jsonString)
{
String json = jsonString;
System.out.println("String jSon no servidor ==>> " + json);
And than because of the User injection in the home interface the following error triggers at runtime:
Caused by: org.jboss.seam.InstantiationException: Could not instantiate Seam component: pesoHome
at org.jboss.seam.Component.newInstance(Component.java:2144)
... 46 more
Caused by: org.jboss.seam.RequiredException: @In attribute requires non-null value: pesoHome.user
Notice that in the body of the request the JSon object brings information about this user wich allows to recover this user using the also injected userPesquisa reference. I know I could have a different approach where I would build a seam component with no references to user and than in it build the user and place it in a new conversation and than inject the home reference I need, but...
I was wondering that probably there should be some more standard approach for this as it is a common scenario. Any suggestions? :)[]s
as suggested by Arthur in this thread comments I have changed a bit the code and now it works:
PesoHome:
@In(required=false)
User user;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
and than in PesoRest:
User usuario = userPesquisa.pesquisaUsuarioPorEmail(email);
pesoHome.setUser(usuario);
And than because now user is not required on creation anymore, the error is not triggered and I can do a late bind after searching DB to recover the correct user. Quite simple solution. Thanks Arthur.
[]s
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