【読書ノート】TiJava——内部類使用例:温室コントローラ
抽象イベントの定義とコントローラの定義を含むコントローラ抽象層:
public abstract class Event {
private long eventTime;
protected final long delayTime;
public Event(long delayTime) {
this.delayTime = delayTime;
}
public void start() { // Allows restarting
eventTime = System.currentTimeMillis() + delayTime;
}
public boolean ready() {
return System.currentTimeMillis() >= eventTime;
}
public void action(){
System.out.println(this);
}
}
public class Controller {
// A class from java.util to hold Event objects:
private List<Event> eventList = new ArrayList<Event>();
public void addEvent(Event c) {
c.start();
eventList.add(c);
}
public void run() throws InterruptedException {
while (eventList.size() > 0)
// Make a copy so you're not modifying the list
// while you're selecting the elements in it:
for (Event e : new ArrayList<Event>(eventList))
if (e.ready()) {
e.action();
eventList.remove(e);
TimeUnit.MILLISECONDS.sleep(100);
}
}
}
内部クラスを使用して、さまざまな特定のイベント動作を定義します.public class GreenhouseControls extends Controller {
private boolean light = false;
public class LightOn extends Event {
public LightOn(long delayTime) {
super(delayTime);
}
public void action() {
// Put hardware control code here to
// physically turn on the light.
super.action();
light = true;
}
public String toString() {
return "Light is on";
}
}
public class LightOff extends Event {
public LightOff(long delayTime) {
super(delayTime);
}
public void action() {
// Put hardware control code here to
// physically turn off the light.
super.action();
light = false;
}
public String toString() {
return "Light is off";
}
}
private boolean water = false;
public class WaterOn extends Event {
public WaterOn(long delayTime) {
super(delayTime);
}
public void action() {
// Put hardware control code here.
super.action();
water = true;
}
public String toString() {
return "Greenhouse water is on";
}
}
public class WaterOff extends Event {
public WaterOff(long delayTime) {
super(delayTime);
}
public void action() {
// Put hardware control code here.
super.action();
water = false;
}
public String toString() {
return "Greenhouse water is off";
}
}
private String thermostat = "Day";
public class ThermostatNight extends Event {
public ThermostatNight(long delayTime) {
super(delayTime);
}
public void action() {
// Put hardware control code here.
super.action();
thermostat = "Night";
}
public String toString() {
return "Thermostat on night setting";
}
}
public class ThermostatDay extends Event {
public ThermostatDay(long delayTime) {
super(delayTime);
}
public void action() {
// Put hardware control code here.
super.action();
thermostat = "Day";
}
public String toString() {
return "Thermostat on day setting";
}
}
public class Bell extends Event {
public Bell(long delayTime) {
super(delayTime);
}
public void action() {
super.action();
}
public String toString() {
return "Bing!";
}
}
public class Restart extends Event {
private List<Event> eventList;
public Restart(long delayTime, List<Event> arrayList) {
super(delayTime);
arrayList.add(this);
this.eventList = new ArrayList<Event>(arrayList);
for (Event e : arrayList)
addEvent(e);
}
public void action() {
super.action();
for (Event e : eventList) {
addEvent(e);
}
}
public String toString() {
return "Restarting system";
}
}
public static class Terminate extends Event {
public Terminate(long delayTime) {
super(delayTime);
}
public void action() {
System.exit(0);
}
public String toString() {
return "Terminating";
}
}
}
スタートコントローラpublic class GreenhouseController {
public static void main(String[] args) throws InterruptedException {
final GreenhouseControls gc = new GreenhouseControls();
gc.new Restart(2000, new ArrayList<Event>() {
{
this.add(gc.new ThermostatNight(0));
this.add(gc.new LightOn(200));
this.add(gc.new LightOff(400));
this.add(gc.new WaterOn(600));
this.add(gc.new WaterOff(800));
this.add(gc.new Bell(900));
this.add(gc.new ThermostatDay(1400));
}
});
if (args.length == 1)
gc.addEvent(new GreenhouseControls.Terminate(new Integer(args[0])));
gc.run();
}
}