question: public Object newProxyInstance ( Class < ? > interfaceClass , String implClassName ) throws Exception { MyInvocationHandler handler = new MyInvocationHandler ( implClassName ) ; return Proxy . newProxyInstance ( interfaceClass . getClassLoader ( ) , new Class [ ] { interfaceClass } , handler ) ; }
target:  Create a proxy instance that implements the specified access interface and delegates incoming invocations to the specified dynamic implementation. The dynamic implementation may change at run-time, and the proxy will always delegates to the up-to-date implementation.