Win a copy of Rust Web Development this week in the Other Languages forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Tim Cooke
  • Campbell Ritchie
  • Ron McLeod
  • Liutauras Vilda
  • Jeanne Boyarsky
Sheriffs:
  • Junilu Lacar
  • Rob Spoor
  • Paul Clapham
Saloon Keepers:
  • Tim Holloway
  • Tim Moores
  • Jesse Silverman
  • Stephan van Hulst
  • Carey Brown
Bartenders:
  • Al Hobbs
  • Piet Souris
  • Frits Walraven

DI - Constructor injection / Setter Injection ?

 
Ranch Hand
Posts: 1491
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
What criteria we choose constructor injection or setter injection ?
 
author & internet detective
Posts: 40913
840
Eclipse IDE VI Editor Java
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Constructor injection is good when you want to force the caller to pass something and not default.

In practice, I tend to use a mix of the two. I use setter injection mainly when:
- Injecting more than one thing
- I don't control the constructor
- I'm only injecting for testing and the "real code" doesn't need to inject.
 
Ranch Hand
Posts: 1936
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Setter injection allows re-injecting. Constructor injection makes sure the client will get fully-configured object.
I prefer setter injection.
 
author
Posts: 38
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I spend several chapters on this subject =)

But the short of it is: prefer Constructor DI almost always, except when you have a circular reference to resolve.
 
Hong Anderson
Ranch Hand
Posts: 1936
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Dhanji Prasanna wrote:
But the short of it is: prefer Constructor DI almost always, except when you have a circular reference to resolve.


Could you please to give a short explanation why you prefer constructor DI?
Thanks.
 
reply
    Bookmark Topic Watch Topic
  • New Topic