// generics/LatentReflection.java

// (c)2017 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.

// Using reflection for latent typing

import java.lang.reflect.*;

// Does not implement Performs:

class Mime {

public void walkAgainstTheWind() {}

public void sit() {

System.out.println("Pretending to sit");

}

public void pushInvisibleWalls() {}

@Override

public String toString() { return "Mime"; }

}

// Does not implement Performs:

class SmartDog {

public void speak() { System.out.println("Woof!"); }

public void sit() { System.out.println("Sitting"); }

public void reproduce() {}

}

class CommunicateReflectively {

public static void perform(Object speaker) {

Class<?> spkr = speaker.getClass();

try {

try {

Method speak = spkr.getMethod("speak");

speak.invoke(speaker);

} catch(NoSuchMethodException e) {

System.out.println(speaker + " cannot speak");

}

try {

Method sit = spkr.getMethod("sit");

sit.invoke(speaker);

} catch(NoSuchMethodException e) {

System.out.println(speaker + " cannot sit");

}

} catch(SecurityException |

IllegalAccessException |

IllegalArgumentException |

InvocationTargetException e) {

throw new RuntimeException(speaker.toString(), e);

}

}

}

public class LatentReflection {

public static void main(String[] args) {

CommunicateReflectively.perform(new SmartDog());

CommunicateReflectively.perform(new Robot());

CommunicateReflectively.perform(new Mime());

}

}

/* Output:

Woof!

Sitting

Click!

Clank!

Mime cannot speak

Pretending to sit

*/