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POJava - Instantiating objects of type X when all you have is the reference type
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  1. POJava - Instantiating objects of type X when all you have is the reference type
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    copied!<p>I had a quick look at the "Related Questions" suggested but I couldn't find one directly related to what I'm asking. Even if there was one, I'd still appreciate your opinion on the best way to do this.</p> <p>First some context.<br> I'm working on extending a Java Application and I have the following Interface and Class:</p> <pre><code>public interface Mapper { public void foo(); } public class SomeGrammar implements Mapper { public SomeGrammar() {} public SomeGrammar(SomeGrammar toCopy) { //Copy specific fields } public void foo() {} } </code></pre> <p>The application I'm using was built with only one grammar type in mind, <code>SomeGrammar</code>, and as such the <code>SomeGrammar</code> class is woven throughout through the application. </p> <p><code>SomeGrammar</code> objects are often copied using a copy constructor:</p> <pre><code>SomeGrammar aGrammar = new SomeGrammar(); SomeGrammar newGrammar = new SomeGrammar(aGrammar); </code></pre> <p>I'm attempting to implement new types of grammars. So I was going to pull the core methods out and implement a <code>Grammar</code> interface, or even consolidate those methods into the <code>Mapper</code> interface. So all grammar classes would implement this interface.</p> <hr> <p>Anyway, my question to you is, what is the best way to go about replacing the above line so that I can generalise the copying of whatever grammar object happens to be currently being referenced by the Interface's Type?</p> <p>Obviously I can't</p> <pre><code>Grammar newGrammar = new Grammar(aGrammar); </code></pre> <p>since <code>Grammar</code> is the Interface's Type, and <code>new Grammar(aGrammar)</code> makes no sense. I suppose I could add a cloning method to my interface to use instead of a copy constructor, but as I said before, I'd appreciate your opinion on the matter.</p> <p>Thanks in advance,<br> Eoin</p>
 

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