OnJava8-Examples/reflection/NullRobot.java at master · CSapprenticeWT/OnJava8-Examples · GitHub

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// reflection/NullRobot.java

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

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

// Using a dynamic proxy to create an Optional

import java.lang.reflect.*;

import java.util.*;

import java.util.stream.*;

import onjava.*;

class NullRobotProxyHandler

implements InvocationHandler {

private String nullName;

private Robot proxied = new NRobot();

NullRobotProxyHandler(Class<? extends Robot> type) {

nullName = type.getSimpleName() + " NullRobot";

}

private class NRobot implements Null, Robot {

@Override

public String name() { return nullName; }

@Override

public String model() { return nullName; }

@Override public List<Operation> operations() {

return Collections.emptyList();

}

@Override public Object

invoke(Object proxy, Method method, Object[] args)

throws Throwable {

return method.invoke(proxied, args);

}

public class NullRobot {

public static Robot

newNullRobot(Class<? extends Robot> type) {

return (Robot)Proxy.newProxyInstance(

NullRobot.class.getClassLoader(),

new Class[]{ Null.class, Robot.class },

new NullRobotProxyHandler(type));

}

public static void main(String[] args) {

Stream.of(

new SnowRobot("SnowBee"),

newNullRobot(SnowRobot.class)

).forEach(Robot::test);

}

/* Output:

Robot name: SnowBee

Robot model: SnowBot Series 11

SnowBee can shovel snow

SnowBee shoveling snow

SnowBee can chip ice

SnowBee chipping ice

SnowBee can clear the roof

SnowBee clearing roof

[Null Robot]

Robot name: SnowRobot NullRobot

Robot model: SnowRobot NullRobot

OnJava8-Examples/reflection/NullRobot.java at master · CSapprenticeWT/OnJava8-Examples · GitHub

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