Databases
StackOverflow2013
Postsdbo
POProper structure for dependency injection (using Guice)
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POProper structure for dependency injection (using Guice)
    primarykey
    data
    text
    <p>I would like some suggestions and feedback on the best way to structure dependency injection for a system with the structure described below. I'm using Guice and thus would prefer solutions centered around it's annotation-based declarations, not XML-heavy Spring-style configuration.</p> <p>Consider a set of similar objects, <code>Ball, Box, and Tube</code>, each dependent on a <code>Logger</code>, supplied via the constructor. (This might not be important, but all four classes happen to be singletons --- of the application, not Gang-of-Four, variety.)</p> <p>A <code>ToyChest</code> class is responsible for creating and managing the three shape objects. <code>ToyChest</code> itself is not dependent on <code>Logger</code>, aside from creating the shape objects which are.</p> <p>The <code>ToyChest</code> class is instantiated as an application singleton in a <code>Main</code> class.</p> <p>I'm confused about the best way to construct the shapes in <code>ToyChest</code>. I either (1) need access to a Guice <code>Injector</code> instance already attached to a <code>Module</code> binding <code>Logger</code> to an implementation or (2) need to create a new <code>Injector</code> attached to the right <code>Module</code>.</p> <p>(1) is accomplished by adding an <code>@Inject Injector injector</code>field to <code>ToyChest</code>, but this feels weird because <code>ToyChest</code> doesn't actually have any direct dependencies --- only those of the children it instantiates.</p> <p>For (2), I'm not sure how to pass in the appropriate <code>Module</code>. </p> <p>Am I on the right track? Is there a better way to structure this?</p> <p>The answers to this <a href="https://stackoverflow.com/questions/2176216/how-to-inject-injector">question</a> mention passing in a <code>Provider</code> instead of using the Injector directly, but I'm not sure how that is supposed to work.</p> <p>EDIT:</p> <p>Perhaps a more simple question is: when using Guice, where is the proper place to construct the shapes objects? <code>ToyChest</code> will do some configuration with them, but I suppose they could be constructed elsewhere. <code>ToyChest</code> (as the container managing them), and not <code>Main</code>, just seems to me like the appropriate place to construct them.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USCommunity
    1. USDavid B.
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POProper structure for dependency injection (using Guice)
      1. This table or related slice is empty.
      1. VTUpMod
    1. COBall, Box and Tube are all application singletons but they are created by ToyChest? Can you clarify why this needs to be the case? Could they instead be given to ToyChest when it was constructed?
      singulars
      1. POProper structure for dependency injection (using Guice)
      1. USWW.
    2. CO1) ToyChest decides which are created. 2) They could be passed in to ToyChest via the constructor, but they are aren't needed anywhere else. So that would (in my opinion) needlessly complicate the constructor. There's also a turtles-all-the-down problem. What creates them to pass to ToyChest? Perhaps passing them in via the constructor is the right way and I'm just not seeing the larger structure.
      singulars
      1. POProper structure for dependency injection (using Guice)
      1. USDavid B.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload