Hi,zhaoyi
u can use the annotation.
public interface Fetcher {
List<Status> fetch() throws HttpException, IOException;
}
public class TwitterFetcher implements Fetcher {
........
}
public class JiwaiFetcher implements Fetcher {
.....
}
and use two annotation to bind each implemention.
@Retention(RetentionPolicy.RUNTIME)
@Target({FIELD, METHOD, PARAMETER})
@BindingAnnotation
public @interface Twitter {
}
@Retention(RetentionPolicy.RUNTIME)
@Target({FIELD, METHOD, PARAMETER})
@BindingAnnotation
public @interface Jiwai {
}
bind(Fetcher.class).annotatedWith(Twitter.class).to(TwitterFetcher.class).in(Singleton.class);
bind(Fetcher.class).annotatedWith(Jiwai.class).to(JiwaiFetcher.class).in(Singleton.class);
then u can inject them.
public class FetchService {
@Inject
@Twitter
Fetcher twitterFetcher;
@Inject
@Jiwai
Fetcher jiwaiFetcher;
public void fetch() {
twitterFetcher.fetch();
...
}
}
On Fri, Aug 14, 2009 at 9:33 AM, zhaoyi <[email protected]> wrote:
>
> Can't I use provider to do this? If I use factory pattern, I only need
> one factory class. However, If I use guice, I have to create one
> factory class, one Module class and one provider class. I think guice
> will make our application more complicated.
>
>
> On Aug 10, 3:00 pm, Brian Pontarelli <[email protected]> wrote:
> > This pattern was common at Orbitz, although more complex. The idea was
> > that you wanted to use a service for booking airline tickets. You
> > would ask the factory for an implementation of the AirBookingService
> > for UA or AA or NWA. Each implementation would talk to the specific
> > airline and talk their special on-the-wire language.
> >
> > We did this in a pretty cool way when we converted to Spring many
> > years back by using a proxy service that would lazy load the real
> > service after calling a lookup based on the request. Looked like this:
> >
> > public class Caller {
> > private AirBookingService service; // injected as a dynamic proxy
> >
> > public String doBooking() {
> > AirBookingRequest request = ...;
> > service.book(request);
> > }
> >
> > }
> >
> > public class AirBookingServiceHandler implements InvocationHandler {
> > private AirLookupService lookup; // injected
> >
> > public Object invoke(Object proxy, Object instance, Object..
> > params) {
> > AirBookingRequest request = (AirBookingRequest) params[0];
> > BookingService service =
> > lookup.lookupService(request.getAirlineCode());
> > return service.book(request);
> > }
> >
> > }
> >
> > That's the general gist of it anyways. The invocation handler was
> > actually generic enough to handle all services and pass calls from the
> > proxy to the correct service implementation. This allowed everything
> > to be injected without having to inject factories everywhere.
> >
> > -bp
> >
> > On Aug 9, 2009, at 3:07 PM, [email protected] wrote:
> >
> >
> >
> > > Hey there,
> >
> > > Generally you wouldn't use a factory in this way - the idea is that
> > > the caller just expects any implementation of the interface returned
> > > therefore the caller specifying the implementation to use doesn't make
> > > sense.
> >
> > > Out of interest, how are you using this particular piece of code?
> >
> > > Cheers
> >
> > > Mark
> >
> > > On Aug 9, 3:04 pm, zhao yi <[email protected]> wrote:
> > >> This is my code based on Factory pattern. I want to use guice and how
> > >> can I convert it to use guice?
> >
> > >> interface Interface1{
> > >> public void sayHello();
> >
> > >> }
> >
> > >> class Imple1 implements Interface1{
> > >> @Override
> > >> public void sayHello() {
> > >> System.out.println("imple 1");
> > >> }
> >
> > >> }
> >
> > >> class Imple2 implements Interface1{
> > >> @Override
> > >> public void sayHello() {
> > >> System.out.println("imple 2");
> > >> }
> >
> > >> }
> >
> > >> class Factory{
> > >> public Interface1 getInterface(int type){
> > >> if(type == 1){
> > >> return new Imple1();
> > >> }else if(type ==2){
> > >> return new Imple2();
> > >> }
> > >> return null;
> > >> }
> >
> > >> }
> >
> > >> thanks.
> >
>
--
My site:http://www.jdkcn.com
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