It's (mostly) a matter of personal preference. I personally also like Constructor Injection better because it clearly establishes the dependencies required for the class in a single location. Also, if you use constructor injection, you can declare your fields final, whereas you can't do that for the field injection.
Robert On Nov 8, 2011, at 11/83:36 PM , Tim Fletcher wrote: > Thanks for your response Thiago! > > Again following the instructions at > http://wiki.apache.org/tapestry/Tapestry5HowToIocOnly > > public class Hello { > > public final Output o; > public Hello(Output o) { > this.o = o; > System.out.println(o); > } > } > > I would like to be able to replace it with > public class Hello { > > @Inject > public final Output o; > public Hello() { > System.out.println(o); > } > } > > However, if i do that currently, i get a Null back. Is there a way to make > the @Inject annotation work in this way? > > Also, could you expand a little on why Constructor Injection is better, or > point me to a resource? > > Again, many thanks, > Tim > > On 8 November 2011 20:37, Thiago H. de Paula Figueiredo > <thiag...@gmail.com>wrote: > >> On Tue, 08 Nov 2011 18:20:40 -0200, Tim Fletcher <zigomu...@gmail.com> >> wrote: >> >> Hi All, >>> >> >> Hi! >> >> I have followed the instructions at [wiki >>> Tapestry5HowToIocOnly]<http://**wiki.apache.org/tapestry/** >>> Tapestry5HowToIocOnly<http://wiki.apache.org/tapestry/Tapestry5HowToIocOnly> >>>> >>> >>> and got that working. However, is it possible to use annotations instead >>> of passing the instance in the constructor? >>> >> >> Tapestry-IoC service dependency injection is the same in and out of >> Tapestry-core (the web framework), so the answer is yes, T-IoC already does >> what you want. >> >> Advice: constructor injection, IMHO, is the best. :) >> >> -- >> Thiago H. de Paula Figueiredo >> Independent Java, Apache Tapestry 5 and Hibernate consultant, developer, >> and instructor >> Owner, Ars Machina Tecnologia da Informação Ltda. >> http://www.arsmachina.com.br >> --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org For additional commands, e-mail: users-h...@tapestry.apache.org
