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POC++Template in Java?
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  1. POC++Template in Java?
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    copied!<p>I want something like this:</p> <pre><code>public abstract class ListenerEx&lt;LISTENER, PARENT&gt; implements LISTENER { PARENT parent; public ListenerEx(PARENT p) { parent = p; } } </code></pre> <p>But it doesn't compile. Is there a better solution? Is there something in Java like C++ template that would do check syntax after template deduction?</p> <hr> <p>The following explains why I need such a ListenerEX class, if you already know what it is, you don't need to read the following.</p> <p>I have a main window, and a button on it, and I want to get access to some method of the main window's within the listener:</p> <pre><code>public class MainWindow extends JFrame { public void doSomething() { /* ... */ } public void doSomethingElse() { /* ... */ } private JButton button; public MainWindow() { button = new JButton(...); add(button); button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { doSomething(); doSomethingElse(); } }); } } </code></pre> <p>This would compile but does not work properly all the time. (Why would it compile when the ActionListener does not have doSomething() method?)</p> <p>Of course we can do it like this:</p> <pre><code>public class MainWindow extends JFrame { public void doSomething() { } public void doSomethingElse() { } private JButton button; public MainWindow() { button = new JButton(...); add(button); class ActionListener1 implements ActionListener { MainWindow parent; public ActionListener(MainWindow p) { parent = p; } public void actionPerformed(ActionEvent e) { parent.doSomething(); parent.doSomethingElse(); } } button.addActionListener(new ActionListener1(this)); } } </code></pre> <p>However I hate this style ...</p> <p>So I tried:</p> <pre><code>public abstract class ActionListenerEx&lt;P&gt; implements ActionListener { P parent; public ActionListenerEx(P p) { parent = p; } } public class MainWindow extends JFrame { public void doSomething() { } public void doSomethingElse() { } private JButton button; public MainWindow() { button = new JButton(...); add(button); button.addActionListener(new ActionListenerEx&lt;MainWindow&gt;(this) { public void actionPerformed(ActionEvent e) { parent.doSomething(); parent.doSomethingElse(); } }); } } </code></pre> <p>But there's lots of Listeners beside the ActionListener ...</p> <pre><code>public abstract class ActionListenerEx&lt;LISTENER, PARENT&gt; implements LISTENER { PARENT parent; public ActionListenerEx(PARENT p) { parent = p; } } </code></pre> <p>However, it won't compile ...</p> <p>I am fresh at Java, and I wonder if there's already better solution.</p>
 

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