Re: Problems implementing Guice / DI the proper way - I end up with allot of factories

[Stephan Classen]

You could move the call to the ConnectionFactory to the HttpClientImpl: class WebCrawler {         private final HttpClientFactory httpClientFactory;         @Inject         public WebCrawler(HttpClientFactory httpFactory) {...}         public crawlDataFrom(Uri uri) {         HttpClient client = httpClientFactory.createClient(uri);         client.doMagicStuff();         } } interface HttpClientFactory {         HttpClient createClient(Uri uri); } class HttpClientImpl implements HttpClient {         private final Connection conn;         @AssistedInject         public HttpClientImpl(@Assisted Uri uri, ConnectionFactory connectionFactory) {                 conn = connectionFactory.create(uri.getHost(), uri.getPort());         } } Or like this: class HttpClientImpl implements HttpClient {         private final Connection conn;         @AssistedInject         public HttpClientImpl(@Assisted Uri uri, ConnectionFactory connectionFactory) {                 this(connectionFactory.create(uri.getHost(), uri.getPort()));         }         public HttpClientImpl(Connection conn) {                 this.conn = conn;         } } And in you module you would bind the assisted inject as follows: install(new FactoryModuleBuilder()      .implement(HttpClient.class, HttpClientImpl.class)      .build(HttpClientFactory.class)); Hope this helps. On 02/22/2013 04:14 PM, David Hoffer wrote: Yes I see that now..missed that.  I do this all the time...so sure would like to know if there is a better way. -Dave On Fri, Feb 22, 2013 at 8:04 AM, Bram <bram...@gmail.com> wrote: Yes, that was my intention (as you can see at the Impl naming of HttpClientFactoryImpl). Op vrijdag 22 februari 2013 14:47:17 UTC+1 schreef dhoffer het volgende: How about also extracting an interface for HttpClientFactoryImpl and let WebCrawler be injected (by Guice) with that interface?  I prefer objects to only know about interfaces of their collaborators. -Dave On Fri, Feb 22, 2013 at 6:32 AM, Bram <bra...@gmail.com> wrote: Thanks for your answers. Would it be possible (and advised?) to implement my own factory logic for, for instance, a HttpClient? I still have a hard time accepting that my WebCrawler has to depend on a connection factory, it doesn't make sense to me (but maby im wrong). (the webcrawler is just an example to keep it simple btw, my own code is pretty domain specific). If I would implement my own factory for the HttpClient it would look something like this:     public class HttpClientFactoryImpl {    public HttpClient createClient(Uri uri) {    Connection conn = connectionFactory.create(uri.getHost(), uri.getPort());    return new HttpClientImpl(conn);    }     }   If my factory would look like that, a webcrawler can only depend on the HttpClientFactory. That factory is, in my opinion, the onwly factory it should depend on. Wy would a webcrawler "know" how to create a connection object? A webcrawler would then look something like this          class WebCrawler {         private final HttpClientFactory httpClientFactory;         public WebCrawler(HttpClientFactory httpFactory) {...}         public crawlDataFrom(Uri uri) {         HttpClient client = httpClientFactory.createClient(uri);         client.doMagicStuff();         }     } Is something like this possible? Is this "better" or bad-practise? I want to prevent creating god-like classes that know allot and/or depend on allot. -- You received this message because you are subscribed to the Google Groups "google-guice" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-guice...@googlegroups.com. To post to this group, send email to google...@googlegroups.com. Visit this group at http://groups.google.com/group/google-guice?hl=en. 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