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POComposite Strategy pattern - java - How bad is this code?
 

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  1. POComposite Strategy pattern - java - How bad is this code?
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    <p>This question is kind of continuation to my earlier post: <a href="https://stackoverflow.com/questions/944824/visitor-pattern-implementation-in-java-how-does-this-look">Visitor pattern implementation in java- How does this look?</a></p> <p>I got a bit confused while refactoring my code. I am trying to convert my visitor pattern (explained in the prior post) into a composite strategy pattern. I am trying to do something like this:</p> <pre><code>public interface Rule { public List&lt;ValidatonError&gt; check(Validatable validatable); } </code></pre> <p>Now, I would define a Rule like this:</p> <pre><code>public class ValidCountryRule { public List&lt;ValidationError&gt; check(Validatable validatable) { // invokeDAO and do something, if violation met // add to a list of ValidationErrors. // return the list. } } </code></pre> <p>Now, I could have two different types objects to be validated. These two could be completely different: Say I have a Store that is <code>Validatable</code>, and then a <code>Schedule</code> which is <code>Validatable</code>. Now, if I would write a composite that would look like this:</p> <pre><code>class Validator implements Rule { private List&lt;Rule&gt; tests = new ArrayList&lt;Rule&gt;(); public void addRule(Rule rule) { tests.add(rule); } public List&lt;ValidationError&gt; check(Visitable visitable) { List&lt;ValidationError&gt; list = new ArrayList&lt;ValidationError&gt;(); for(Rule rule : tests) { list.addAll(rule.check(visitable); } } public Validator(ValidatorType type) { this.tests = type.getRules(); } } </code></pre> <p>I would define an <code>enum</code> that defines what set of checks go where...</p> <pre><code>public Enum ValidatorType { public abstract List&lt;Rule&gt; getRules(); STORE_VALIDATOR { public List&lt;Rule&gt; getRules() { List&lt;Rule&gt; rules = new ArrayList&lt;Rule&gt;(); rules.add(new ValidCountryRule()); rules.add(new ValidXYZRule()); } // more validators } </code></pre> <p>and finally, I would use it like this:</p> <pre><code>Validator validator = new Validator(ValidatorType.STORE_VALIDATOR); for (Store store : stores) { validator.check(store); } </code></pre> <p>I have a strange feeling that my design is flawed. I am not liking the idea that my Rule interface expects a <code>Validatable</code>. Could you please suggest how I would improve this?</p> <p>Appreciate your help.</p>
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    1. COYou are breaking all the rules of indentation. If you want others to look at and help you with something your code needs to look a little better. Right now it has horrible code smell.
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    2. CO@Trevor Sorry about that, fixed it now.
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    3. COThe indentation was still somewhat unreadable. I fixed it.
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