LazyInitWithProxyServiceFactory.java

public class LazyInitWithProxyServiceFactory {
    
    public static Service createService() {
        return Reflection.newProxy(Service.class, new LazyInitInvocationHandler());
    }

    private static class LazyInitInvocationHandler extends AbstractInvocationHandler {
        private Service service;

        @Override
        protected Object handleInvocation(Object proxy, Method method, Object[] args) throws Throwable {
            return method.invoke(service(), args);
        }

        private Service service() {
            if (service == null) {
                service = new DefaultService();
            }
            return service;
        }
    }
}