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PODynamically instantiating abstract subclass
 

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    <p>First I have to say I am real new to Java. So all apologize if my question sound stupid but I haven't been able to find a solution so far...</p> <p>I would like to dynamically instantiate a abstract class subclass.</p> <p>This is the code</p> <pre><code>public class CommandMap implements Handler.Callback { private HashMap &lt;Integer, Class&lt;? extends AbstractCommand&gt; &gt; __commandHashMap; protected CommandMap() { __commandHashMap = new HashMap&lt;Integer, Class&lt;? extends AbstractCommand&gt;&gt;(); } /** * Map an ID to a command * @param what Id used in the Message sent * @param command Command to be executed */ public void mapWhat(Integer what, Class&lt;? extends AbstractCommand&gt; command) { if ( !__commandHashMap.containsKey(what) ) { __commandHashMap.put(what, command); } } /** * Unmap the id/command pair * @param what Id */ public void unmapWhat(Integer what) { if ( __commandHashMap.containsKey(what) ) { __commandHashMap.remove(what); } } public boolean handleMessage (Message message) { // call the corresponding command if ( __commandHashMap.containsKey(message.what) ) { Class&lt;? extends AbstractCommand&gt; commandClass = __commandHashMap.get(message.what); AbstractCommand command = commandClass.getClass().newInstance(); } return true; // for now } } </code></pre> <p>When doing so the part</p> <pre><code>AbstractCommand command = commandClass.getClass().newInstance(); </code></pre> <p>is giving me an error (illegalAccessException and InstantiationException) in my IDE (not at compile time as I haven't tried it yet) </p> <p>so I surround it with try/catch like this</p> <pre><code>public boolean handleMessage (Message message) { // call the corresponding command if ( __commandHashMap.containsKey(message.what) ) { Class&lt;? extends AbstractCommand&gt; commandClass = __commandHashMap.get(message.what); try { AbstractCommand command = commandClass.getClass().newInstance(); } catch (IllegalAccessException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } catch (InstantiationException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } } return true; // for now } </code></pre> <p>but then it tells me that the type Class (sent by the newInstance() ) is obvisouly not of type AbstractCommand.</p> <p>When trying to cast Class to AbstractCommand doing</p> <pre><code>AbstractCommand command = (AbstractCommand) commandClass.getClass().newInstance(); </code></pre> <p>It tells me that Class cannot be cast to AbstractCommand.</p> <p>So I was wondering what I am doing wrong ?</p> <p>Thanks again for any help you could provide.</p>
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