#107 Improve JavaDoc for Observer example

This commit is contained in:
Ilkka Seppala 2015-08-21 22:28:51 +03:00
parent 86c68f96e3
commit 520f81d62e
11 changed files with 208 additions and 156 deletions

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@ -1,38 +1,41 @@
package com.iluwatar.observer; package com.iluwatar.observer;
import com.iluwatar.observer.generic.GHobbits; import com.iluwatar.observer.generic.GHobbits;
import com.iluwatar.observer.generic.GOrcs; import com.iluwatar.observer.generic.GOrcs;
import com.iluwatar.observer.generic.GWeather; import com.iluwatar.observer.generic.GWeather;
/** /**
* *
* Observer pattern defines one-to-many relationship between objects. The target * Observer pattern defines one-to-many relationship between objects. The target
* object sends change notifications to its registered observers. * object sends change notifications to its registered observers.
* *
*/ */
public class App { public class App {
public static void main(String[] args) { /**
* Program entry point
Weather weather = new Weather(); * @param args command line args
weather.addObserver(new Orcs()); */
weather.addObserver(new Hobbits()); public static void main(String[] args) {
weather.timePasses(); Weather weather = new Weather();
weather.timePasses(); weather.addObserver(new Orcs());
weather.timePasses(); weather.addObserver(new Hobbits());
weather.timePasses();
weather.timePasses();
// Generic observer inspired by Java Generics and Collection by Naftalin & Wadler weather.timePasses();
System.out.println("\n--Running generic version--"); weather.timePasses();
GWeather gWeather = new GWeather(); weather.timePasses();
gWeather.addObserver(new GOrcs());
gWeather.addObserver(new GHobbits()); // Generic observer inspired by Java Generics and Collection by Naftalin & Wadler
System.out.println("\n--Running generic version--");
gWeather.timePasses(); GWeather gWeather = new GWeather();
gWeather.timePasses(); gWeather.addObserver(new GOrcs());
gWeather.timePasses(); gWeather.addObserver(new GHobbits());
gWeather.timePasses();
gWeather.timePasses();
} gWeather.timePasses();
} gWeather.timePasses();
gWeather.timePasses();
}
}

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@ -1,25 +1,30 @@
package com.iluwatar.observer; package com.iluwatar.observer;
public class Hobbits implements WeatherObserver { /**
*
@Override * Hobbits
public void update(WeatherType currentWeather) { *
switch (currentWeather) { */
case COLD: public class Hobbits implements WeatherObserver {
System.out.println("The hobbits are shivering in the cold weather.");
break; @Override
case RAINY: public void update(WeatherType currentWeather) {
System.out.println("The hobbits look for cover from the rain."); switch (currentWeather) {
break; case COLD:
case SUNNY: System.out.println("The hobbits are shivering in the cold weather.");
System.out.println("The happy hobbits bade in the warm sun."); break;
break; case RAINY:
case WINDY: System.out.println("The hobbits look for cover from the rain.");
System.out.println("The hobbits hold their hats tightly in the windy weather."); break;
break; case SUNNY:
default: System.out.println("The happy hobbits bade in the warm sun.");
break; break;
} case WINDY:
} System.out.println("The hobbits hold their hats tightly in the windy weather.");
break;
} default:
break;
}
}
}

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@ -1,25 +1,30 @@
package com.iluwatar.observer; package com.iluwatar.observer;
public class Orcs implements WeatherObserver { /**
*
@Override * Orcs
public void update(WeatherType currentWeather) { *
switch (currentWeather) { */
case COLD: public class Orcs implements WeatherObserver {
System.out.println("The orcs are freezing cold.");
break; @Override
case RAINY: public void update(WeatherType currentWeather) {
System.out.println("The orcs are dripping wet."); switch (currentWeather) {
break; case COLD:
case SUNNY: System.out.println("The orcs are freezing cold.");
System.out.println("The sun hurts the orcs' eyes."); break;
break; case RAINY:
case WINDY: System.out.println("The orcs are dripping wet.");
System.out.println("The orc smell almost vanishes in the wind."); break;
break; case SUNNY:
default: System.out.println("The sun hurts the orcs' eyes.");
break; break;
} case WINDY:
} System.out.println("The orc smell almost vanishes in the wind.");
break;
} default:
break;
}
}
}

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@ -1,42 +1,42 @@
package com.iluwatar.observer; package com.iluwatar.observer;
import java.util.ArrayList; import java.util.ArrayList;
import java.util.List; import java.util.List;
/** /**
* *
* Weather can be observed by implementing WeatherObserver interface and * Weather can be observed by implementing {@link WeatherObserver} interface and
* registering as listener. * registering as listener.
* *
*/ */
public class Weather { public class Weather {
private WeatherType currentWeather; private WeatherType currentWeather;
private List<WeatherObserver> observers; private List<WeatherObserver> observers;
public Weather() { public Weather() {
observers = new ArrayList<>(); observers = new ArrayList<>();
currentWeather = WeatherType.SUNNY; currentWeather = WeatherType.SUNNY;
} }
public void addObserver(WeatherObserver obs) { public void addObserver(WeatherObserver obs) {
observers.add(obs); observers.add(obs);
} }
public void removeObserver(WeatherObserver obs) { public void removeObserver(WeatherObserver obs) {
observers.remove(obs); observers.remove(obs);
} }
public void timePasses() { public void timePasses() {
WeatherType[] enumValues = WeatherType.values(); WeatherType[] enumValues = WeatherType.values();
currentWeather = enumValues[(currentWeather.ordinal() + 1) % enumValues.length]; currentWeather = enumValues[(currentWeather.ordinal() + 1) % enumValues.length];
System.out.println("The weather changed to " + currentWeather + "."); System.out.println("The weather changed to " + currentWeather + ".");
notifyObservers(); notifyObservers();
} }
private void notifyObservers() { private void notifyObservers() {
for (WeatherObserver obs : observers) { for (WeatherObserver obs : observers) {
obs.update(currentWeather); obs.update(currentWeather);
} }
} }
} }

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@ -1,12 +1,17 @@
package com.iluwatar.observer; package com.iluwatar.observer;
public enum WeatherType { /**
*
SUNNY, RAINY, WINDY, COLD; * WeatherType enumeration
*
@Override */
public String toString() { public enum WeatherType {
return this.name().toLowerCase();
} SUNNY, RAINY, WINDY, COLD;
} @Override
public String toString() {
return this.name().toLowerCase();
}
}

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@ -2,6 +2,11 @@ package com.iluwatar.observer.generic;
import com.iluwatar.observer.WeatherType; import com.iluwatar.observer.WeatherType;
/**
*
* GHobbits
*
*/
public class GHobbits implements Race { public class GHobbits implements Race {
@Override @Override
public void update(GWeather weather, WeatherType weatherType) { public void update(GWeather weather, WeatherType weatherType) {

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@ -2,7 +2,13 @@ package com.iluwatar.observer.generic;
import com.iluwatar.observer.WeatherType; import com.iluwatar.observer.WeatherType;
/**
*
* GOrcs
*
*/
public class GOrcs implements Race { public class GOrcs implements Race {
@Override @Override
public void update(GWeather weather, WeatherType weatherType) { public void update(GWeather weather, WeatherType weatherType) {
switch (weatherType) { switch (weatherType) {

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@ -2,6 +2,11 @@ package com.iluwatar.observer.generic;
import com.iluwatar.observer.WeatherType; import com.iluwatar.observer.WeatherType;
/**
*
* GWeather
*
*/
public class GWeather extends Observable<GWeather, Race, WeatherType> { public class GWeather extends Observable<GWeather, Race, WeatherType> {
private WeatherType currentWeather; private WeatherType currentWeather;

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@ -1,5 +1,13 @@
package com.iluwatar.observer.generic; package com.iluwatar.observer.generic;
/**
*
* Observer
*
* @param <S>
* @param <O>
* @param <A>
*/
public interface Observer<S extends Observable<S, O, A>, O extends Observer<S, O, A>, A> { public interface Observer<S extends Observable<S, O, A>, O extends Observer<S, O, A>, A> {
void update(S subject, A argument); void update(S subject, A argument);

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@ -2,5 +2,10 @@ package com.iluwatar.observer.generic;
import com.iluwatar.observer.WeatherType; import com.iluwatar.observer.WeatherType;
/**
*
* Race
*
*/
public interface Race extends Observer<GWeather, Race, WeatherType> { public interface Race extends Observer<GWeather, Race, WeatherType> {
} }

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@ -1,14 +1,19 @@
package com.iluwatar.observer; package com.iluwatar.observer;
import org.junit.Test; import org.junit.Test;
import com.iluwatar.observer.App; import com.iluwatar.observer.App;
public class AppTest { /**
*
@Test * Application test
public void test() { *
String[] args = {}; */
App.main(args); public class AppTest {
}
} @Test
public void test() {
String[] args = {};
App.main(args);
}
}