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PONewbie question about Dependency Injection when a method needs to create new objects
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copied!<p>I've been reading about dependency injection and have a simple question. I can understand how via constructor or setter injection required dependencies are autowired by the DI framework. What happens when an object decides it needs to create a new object due to some business process? Do I need to always create a Factory in these situations? To make it a less abstract question, here is an example.</p> <p>Let's say I'm writing a game of Asteriods. There's a ship in the middle which can spin around and shoot the asteriods. Assume that the ship has been created and approriate things injected. When <code>playerShip.shoot()</code> is called we need to create a <code>bullet</code> object. The bullet object needs to know which way it is going (<code>direction</code>) and where to start (<code>point</code>).</p> <p>Normally, I would do something like this:</p> <pre><code>bullet = new Bullet( direction, point ); </code></pre> <p>However, that tightly couples the PlayerShip class to the Bullet class. How should this work under dependency injection? Do I need to create a BulletFactory interface and inject an implementation of that into the ship?</p> <p>Edit: I'm not actually writing asteriods. This was a simple example that I thought people would understand. I wanted something that needed to be created a runtime (not while "wiring up objects") that also had parameters to it's constructor.</p>

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