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copied!<p>I would suggest a <a href="http://en.wikipedia.org/wiki/Proxy_pattern" rel="nofollow noreferrer">Proxy</a>. Here's the <a href="http://java.sun.com/j2se/1.4.2/docs/guide/reflection/proxy.html" rel="nofollow noreferrer">Java example</a>.</p> <pre><code>public interface Bike { public String getWheels(); public int getSize(); } public class MountainBike implements Bike { @Override public int getSize() { return 24; } @Override public String getWheels() { return "Treaded"; } @Override public String toString() { String newLine = System.getProperty("line.separator"); StringBuilder sb = new StringBuilder(); sb.append("Type: MOUNTAIN").append(newLine); sb.append("Wheels: ").append(getWheels()).append(newLine); sb.append("Size: ").append(getSize()).append(newLine); return sb.toString(); } } public class CruiserBike implements Bike { @Override public int getSize() { return 26; } @Override public String getWheels() { return "Smooth"; } @Override public String toString() { String newLine = System.getProperty("line.separator"); StringBuilder sb = new StringBuilder(); sb.append("Type: CRUISER").append(newLine); sb.append("Wheels: ").append(getWheels()).append(newLine); sb.append("Size: ").append(getSize()).append(newLine); return sb.toString(); } } public class BikeProxy implements InvocationHandler { private Object obj; public static Object newInstance(Object obj) { return java.lang.reflect.Proxy.newProxyInstance(obj.getClass() .getClassLoader(), obj.getClass().getInterfaces(), new BikeProxy(obj)); } public static <T> T newInstance(String className) { try { return (T) newInstance(Class.forName(className)); } catch (ClassNotFoundException e) { throw new RuntimeException(e); } } public static <T> T newInstance(Class<T> bikeClass) { try { return (T) java.lang.reflect.Proxy.newProxyInstance(Bike.class.getClassLoader(), new Class[]{Bike.class}, new BikeProxy(bikeClass.newInstance())); } catch (Exception e) { throw new RuntimeException(e); } } private BikeProxy(Object obj) { this.obj = obj; } public Object invoke(Object proxy, Method m, Object[] args) throws Throwable { Object result; try { result = m.invoke(obj, args); } catch (InvocationTargetException e) { throw e.getTargetException(); } catch (Exception e) { throw new RuntimeException(e); } return result; } } public class ProxyTester { public static void main(String[] args) { Bike mountainBike = BikeProxy.newInstance(MountainBike.class); System.out.println(mountainBike); Bike mountainBike2 = BikeProxy.newInstance(MountainBike.class.getName()); System.out.println(mountainBike2); Bike cruiserBike = BikeProxy.newInstance(CruiserBike.class); System.out.println(cruiserBike); Bike cruiserBike2 = BikeProxy.newInstance(CruiserBike.class.getName()); System.out.println(cruiserBike2); } } </code></pre>

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