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POjava, initialize SubClass from SuperClass
 

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    <pre><code>public class Base { //long list of attributes // no Constructor using fields // no init methode // i cannot change this class } </code></pre> <p>now i extended the Base Class like:</p> <pre><code>public class subClass extends Base{ private boolean selected; ... getter und setter ... } </code></pre> <p>i become a list of Base object <code>List&lt;Base&gt;</code> </p> <p>but i need the same list but as <code>List&lt;SubClass&gt;</code> is there a way to initialize the Subclass from the Base Class?</p> <p>example:</p> <pre><code>for(Base b: list){ SubClass sub = (SubClass)b; // Thats wrong i know if(...){ sub.setSelected(true); } newList.add(sub); } </code></pre> <p>i try to avoid the manual init of each Attribute of the Base <code>Class</code> to the SubClass</p> <p>i update my Question as requested in the Comments: the Design above is just an example. my QUESTIN EXACTLY IS:</p> <p>why converting BaseClass into SubClass (sence <code>Subclass extends BaseClass</code>) is not Possible? why Java dosn't allow me to do the following:</p> <p>example:</p> <pre><code>Class Base{ private String name; ..... } Class SubClass extends Base{ private String title; } </code></pre> <p>then</p> <pre><code>Base b = DBController.getById(...); SubClass sub = (SubClass)b; </code></pre> <p>after that the Object <code>sub</code> should have the Attribute Name from the Object <code>b</code> and the <code>title</code> Attribute is null</p> <p>why is this not the case in java?</p> <p>sorry for my bad english, thanks</p>
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    1. COInitialize subclass from superclass -- why? This sounds ill conceived at best and dangerous at worst.
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    2. COWhere is the `List<Base>` field defined? In the `Base` class itself? Do you have control over where its declared and how its initialized?
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    3. COI highly suggest you look into "prefer Composition over inheritence"--google it. You will find some interesting discussions on the matter. I only say this because it looks like you are attempting desperately to abuse the privilege.
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