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copied!<p>From the few times that I came across this "need", it ultimately boils down to this construct:</p> <pre><code>public class Foo<T> { private T t; public Foo() { this.t = new T(); // Help? } } </code></pre> <p>This does work in C# assuming that <code>T</code> has a <em>default</em> constructor. You can even get the runtime type by <a href="http://msdn.microsoft.com/en-us/library/58918ffs.aspx" rel="noreferrer"><code>typeof(T)</code></a> and get the constructors by <a href="http://msdn.microsoft.com/en-us/library/system.type.aspx" rel="noreferrer"><code>Type.GetConstructor()</code></a>.</p> <p>The common Java solution would be to pass the <code>Class<T></code> as argument.</p> <pre><code>public class Foo<T> { private T t; public Foo(Class<T> cls) throws Exception { this.t = cls.newInstance(); } } </code></pre> <p><em>(it does not necessarily need to be passed as constructor argument, as a method argument is also fine, the above is just an example, also the <code>try-catch</code> is omitted for brevity)</em></p> <p>For all other generic type constructs, the actual type can easily be resolved with a bit help of reflection. The below Q&A illustrate the use cases and possibilities:</p> <ul> <li><a href="https://stackoverflow.com/questions/1942644/get-generic-type-of-java-util-list/">Get generic type of java.util.List</a></li> <li><a href="https://stackoverflow.com/questions/3941384/how-to-get-the-generic-type-at-runtime/">How to get the generic type at runtime?</a></li> <li><a href="https://stackoverflow.com/questions/18707582/get-actual-type-of-generic-type-argument-on-abstract-superclass/">Get actual type of generic type argument on abstract superclass</a></li> </ul>

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