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// reflection/HiddenImplementation.java

// (c)2021 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

// Sneaking around package hiding

import reflection.interfacea.*;

import reflection.packageaccess.*;

import java.lang.reflect.*;

public class HiddenImplementation {

public static void

main(String[] args) throws Exception {

A a = HiddenC.makeA();

a.f();

System.out.println(a.getClass().getName());

// Compile error: cannot find symbol 'C':

/* if(a instanceof C) {

C c = (C)a;

c.g();

} */

// Oops! Reflection still allows us to call g():

callHiddenMethod(a, "g");

// And even less accessible methods!

callHiddenMethod(a, "u");

callHiddenMethod(a, "v");

callHiddenMethod(a, "w");

}

static void

callHiddenMethod(Object a, String methodName)

throws Exception {

Method g =

a.getClass().getDeclaredMethod(methodName);

g.setAccessible(true);

g.invoke(a);

}

}

/* Output:

public C.f()

reflection.packageaccess.C

public C.g()

package C.u()

protected C.v()

private C.w()

*/