├── .gitignore
├── README.md
├── build.gradle
├── reactive_thinking.iml
├── slides
    ├── RXJava_Lviv.pdf
    └── RXJava_Princeton_JUG.pdf
└── src
    └── main
        └── java
            └── yfain
                └── presentation
                    └── rxjava
                        ├── BeerClient.java
                        ├── BeerClientWithFailover.java
                        ├── BeerServer.java
                        ├── BeerServerWithFailover.java
                        ├── HelloObservable.java
                        ├── ObservableErrorComplete.java
                        ├── StreamVsObservable.java
                        ├── composingObservables
                            └── ObservableDrinks.java
                        ├── drink
                            ├── Beer.java
                            ├── Drink.java
                            └── SoftDrink.java
                        ├── schedulers
                            ├── ParallelStreams.java
                            └── SubscribeOnObserveOn.java
                        └── stock
                            ├── BeerStock.java
                            └── SoftDrinkStock.java


/.gitignore:
--------------------------------------------------------------------------------
1 | out
2 | .idea
3 | .gradle
4 | build
5 | gradle
6 | gradlew
7 | gradlew.bat
8 | *.iml


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/README.md:
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1 | # rxjava
2 | Code samples for the RxJava presentations
3 | 
4 | My RxJava2 repo is here: https://github.com/yfain/rxjava2
5 | 


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/build.gradle:
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 1 | apply plugin: 'java'
 2 | 
 3 | sourceCompatibility = '1.8'
 4 | 
 5 | repositories {
 6 |     jcenter()
 7 | }
 8 | 
 9 | dependencies {
10 | // https://mvnrepository.com/artifact/io.reactivex/rxjava
11 |     compile group: 'io.reactivex', name: 'rxjava', version: '1.2.6'
12 | 
13 | }
14 | 
15 | task wrapper(type: Wrapper){
16 |     gradleVersion = '3.4'
17 | }


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/reactive_thinking.iml:
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 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <module type="JAVA_MODULE" version="4">
 3 |   <component name="NewModuleRootManager" inherit-compiler-output="true">
 4 |     <exclude-output />
 5 |     <content url="file://$MODULE_DIR$">
 6 |       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
 7 |     </content>
 8 |     <orderEntry type="inheritedJdk" />
 9 |     <orderEntry type="sourceFolder" forTests="false" />
10 |     <orderEntry type="library" name="rxjava-1.1.3" level="project" />
11 |   </component>
12 | </module>


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/slides/RXJava_Lviv.pdf:
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https://raw.githubusercontent.com/yfain/rxjava/8c5dafcaae1d26c4949b7343d2ba8780d172a555/slides/RXJava_Lviv.pdf


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/slides/RXJava_Princeton_JUG.pdf:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/yfain/rxjava/8c5dafcaae1d26c4949b7343d2ba8780d172a555/slides/RXJava_Princeton_JUG.pdf


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/src/main/java/yfain/presentation/rxjava/BeerClient.java:
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 1 | package yfain.presentation.rxjava;
 2 | 
 3 | import rx.Observable;
 4 | import rx.Subscriber;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | 
 7 | public class BeerClient {
 8 |     public static void main(String[] args) {
 9 | 
10 |         Observable<Beer> beerData = BeerServer.getData(); // no data coming in yet!!!
11 | 
12 |         beerData
13 |             .subscribe(new Subscriber<Beer>() {
14 | 
15 |                 // Implementing the Observer
16 |                 public void onNext(Beer beer) {
17 |                     System.out.println(beer);
18 |                 }
19 | 
20 |                 public void onError(Throwable throwable) {
21 |                     System.err.println("Client received: " + throwable.getMessage());
22 |                 }
23 | 
24 |                 public void onCompleted() {
25 |                     System.out.println("*** The stream is over ***");
26 |                 }
27 |         });
28 |     }
29 | }


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/src/main/java/yfain/presentation/rxjava/BeerClientWithFailover.java:
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 1 | package yfain.presentation.rxjava; /**
 2 |  * Created by yfain11 on 4/19/16.
 3 |  */
 4 | import rx.Observable;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | 
 7 | public class BeerClientWithFailover {
 8 |     public static void main(String[] args) {
 9 | 
10 |         Observable<Beer> beerData = BeerServerWithFailover.getData(); // get data from main server
11 | 
12 |         beerData
13 |             .onErrorResumeNext(err -> {
14 |                 System.out.println("!!! Switching to an alternative data source because of : "+ err.getMessage());
15 |                 return BeerServerWithFailover.getDataFromAnotherServer();})   // get data from alternative server
16 |             .subscribe(
17 |                 // Implementing the observer
18 |                 beer -> System.out.println(beer),
19 |                 (error) -> System.err.println("Client received: " + error.getMessage()),
20 |                 () -> System.out.println("*** The stream is over ***")
21 |         );
22 |     }
23 | }


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/src/main/java/yfain/presentation/rxjava/BeerServer.java:
--------------------------------------------------------------------------------
 1 | package yfain.presentation.rxjava;
 2 | 
 3 | import rx.Observable;
 4 | import rx.Subscriber;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | import yfain.presentation.rxjava.stock.BeerStock;
 7 | 
 8 | public class BeerServer {
 9 | 
10 |     private static BeerStock beerStock = new BeerStock();
11 | 
12 | 
13 |     public static Observable<Beer> getData(){
14 | 
15 |         System.out.println("*** Getting beers from the main data source ***");
16 | 
17 |         // Create an observable passing subscriber (implements Observer)
18 |         // provided by the client
19 | 
20 |         Observable.OnSubscribe<Beer> onSubscribe = subscriber -> {
21 |             beerStock.forEach(beer -> BeerServer.subscribeBeer(subscriber, beer));
22 |             subscriber.onCompleted();
23 |         };
24 | 
25 |         return Observable.create(onSubscribe);
26 |     }
27 | 
28 |     static void subscribeBeer(Subscriber<? super Beer> subscriber, Beer beer) {
29 |         subscriber.onNext(beer);
30 | 
31 |         try {
32 |             Thread.sleep(500); // Emulating delay in getting data
33 |         } catch (InterruptedException e) {
34 |             subscriber.onError(new Throwable("Error in getting beer info"));
35 |         }
36 |     }
37 | }
38 | 


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/src/main/java/yfain/presentation/rxjava/BeerServerWithFailover.java:
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 1 | package yfain.presentation.rxjava; /**
 2 |  * Created by yfain11 on 4/19/16.
 3 |  */
 4 | import rx.Observable;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | 
 7 | import java.util.ArrayList;
 8 | import java.util.List;
 9 | 
10 | public class BeerServerWithFailover {
11 | 
12 |     public static Observable<Beer> getData(){
13 | 
14 |         loadSeller();
15 |         System.out.println("*** Getting beers from the main data source ***");
16 | 
17 |         // Create an observable passing subscriber (implements Observer)
18 |         // provided by the client
19 |         return
20 |                 Observable.create(subscriber -> {
21 |                     try {
22 |                         for (int i = 0; i < beerStock.size(); i++) {
23 | 
24 |                             subscriber.onNext(beerStock.get(i));
25 | 
26 |                             Thread.sleep(500); // Emulating delay in getting data
27 | 
28 |                             if (Math.random() <0.3){  // Emulating data error
29 |                                 throw new Throwable("Some stupid error");
30 |                             }
31 |                         }
32 |                     } catch(Throwable err){
33 |                         //err.printStackTrace();
34 |                         subscriber.onError(new Throwable("Error in getting beer info"));
35 |                     }
36 | 
37 |                     subscriber.onCompleted();
38 |                 });
39 |     }
40 | 
41 |     static List<Beer> beerStock = new ArrayList<>();
42 | 
43 |     private static  void loadSeller(){
44 |         beerStock.add(new Beer("Obolon", "Ukraine", 4.00f));
45 |         beerStock.add(new Beer("Stella", "Belgium", 7.75f));
46 |         beerStock.add(new Beer("Sam Adams", "USA", 7.00f));
47 |         beerStock.add(new Beer("Bud Light", "USA", 5.00f));
48 |         beerStock.add(new Beer("Yuengling", "USA", 5.50f));
49 |         beerStock.add(new Beer("Leffe Blonde", "Belgium", 8.75f));
50 |         beerStock.add(new Beer("Chimay Blue", "Belgium", 10.00f));
51 |         beerStock.add(new Beer("Brooklyn Lager", "USA", 8.25f));
52 | 
53 |     }
54 | 
55 | 
56 |     public static Observable<Beer> getDataFromAnotherServer(){
57 | 
58 |         System.out.println("*** Getting beers from the ALTERNATIVE data source ***");
59 | 
60 |         return
61 |                 Observable.create(subscriber -> {
62 |                     try {
63 |                         for (int i = 0; i < beerStock.size(); i++) {
64 | 
65 |                             subscriber.onNext(beerStock.get(i));
66 | 
67 |                             Thread.sleep(1000); // Emulating delay in getting data
68 | 
69 |                         }
70 |                     } catch(Throwable err){
71 |                         subscriber.onError(new Throwable("Error in getting beer info"));
72 |                     }
73 | 
74 |                     subscriber.onCompleted();
75 |                 });
76 |     }
77 | }
78 | 
79 | 


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/src/main/java/yfain/presentation/rxjava/HelloObservable.java:
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 1 | package yfain.presentation.rxjava; /**
 2 |  * Created by yfain11 on 4/9/16.
 3 |  */
 4 | import rx.Observable;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | import yfain.presentation.rxjava.stock.BeerStock;
 7 | 
 8 | public class HelloObservable {
 9 | 
10 |     private static BeerStock beerStock = new BeerStock();
11 | 
12 |     public static void main(String[] args) {
13 | 
14 | 
15 |         Observable<Beer> observableBeer = Observable.from(beerStock);   // Create Observable from List
16 | 
17 |         observableBeer.subscribe(System.out::println);    // onNext handler
18 |     }
19 | }
20 | 


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/src/main/java/yfain/presentation/rxjava/ObservableErrorComplete.java:
--------------------------------------------------------------------------------
 1 | package yfain.presentation.rxjava; /**
 2 |  * Created by yfain11 on 4/9/16.
 3 |  */
 4 | 
 5 | import rx.Observable;
 6 | import yfain.presentation.rxjava.drink.Beer;
 7 | import yfain.presentation.rxjava.stock.BeerStock;
 8 | 
 9 | public class ObservableErrorComplete {
10 | 
11 |     private static BeerStock beerStock = new BeerStock();
12 | 
13 |     public static void main(String[] args) {
14 | 
15 |         System.out.println("== Observable creation from an Iterable");
16 | 
17 |         Observable<Beer> observableBeer = Observable.from(beerStock);
18 | 
19 |         observableBeer.subscribe(
20 |                 beer -> System.out.println(beer),
21 |                 error -> System.err.println(error),
22 |                 () -> System.out.println("Streaming is over")
23 |         );
24 |     }
25 | }
26 | 


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/src/main/java/yfain/presentation/rxjava/StreamVsObservable.java:
--------------------------------------------------------------------------------
 1 | package yfain.presentation.rxjava; /**
 2 |  * Created by yfain11 on 4/9/16.
 3 |  */
 4 | import rx.Observable;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | import yfain.presentation.rxjava.stock.BeerStock;
 7 | 
 8 | public class StreamVsObservable {
 9 | 
10 |     private static BeerStock beerStock = new BeerStock();
11 | 
12 |     public static void main(String[] args) {
13 | 
14 |         // === Java 8 Stream
15 |         System.out.println("\n== Iterating over Java 8 Stream");
16 | 
17 |         beerStock.stream()
18 |                 .skip(1)
19 |                 .limit(3)
20 |                 .filter(StreamVsObservable::isMadeInUSA)
21 |                 .map(StreamVsObservable::mapWithPrice)
22 |                 .forEach(System.out::println);
23 | 
24 |         // === RxJava Observable
25 | 
26 |         Observable<Beer> observableBeer = null;
27 | 
28 |         System.out.println("\n== Subscribing to Observable ");
29 | 
30 |         observableBeer = Observable.from(beerStock);
31 | 
32 |         observableBeer
33 |                 .skip(1)
34 |                 .take(3)
35 |                 .filter(StreamVsObservable::isMadeInUSA)
36 |                 .map(StreamVsObservable::mapWithPrice)
37 |                 .subscribe(
38 |                         beer -> System.out.println(beer),
39 |                         err -> System.out.println(err),
40 |                         () -> System.out.println("Streaming is complete")
41 |         );
42 |     }
43 | 
44 |     static boolean isMadeInUSA(Beer beer){
45 |         return "USA".equals(beer.country);
46 |     }
47 | 
48 |     static String mapWithPrice(Beer beer) {
49 |         return beer.name + ": $" + beer.price;
50 |     }
51 | }
52 | 


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/src/main/java/yfain/presentation/rxjava/composingObservables/ObservableDrinks.java:
--------------------------------------------------------------------------------
 1 | package yfain.presentation.rxjava.composingObservables;
 2 | 
 3 | import rx.Observable;
 4 | import yfain.presentation.rxjava.drink.Beer;
 5 | import yfain.presentation.rxjava.drink.Drink;
 6 | import yfain.presentation.rxjava.drink.SoftDrink;
 7 | import yfain.presentation.rxjava.stock.BeerStock;
 8 | import yfain.presentation.rxjava.stock.SoftDrinkStock;
 9 | 
10 | import java.util.ArrayList;
11 | import java.util.List;
12 | 
13 | public class ObservableDrinks {
14 | 
15 |     static List<List<? extends Drink>> drinks = new ArrayList<>();
16 | 
17 | 
18 |     static List<? extends Drink> beerStock = new BeerStock();
19 | 
20 | 
21 |     static List<? extends Drink> softStock = new SoftDrinkStock();
22 | 
23 | 
24 |     public static Observable<List<? extends Drink>> getDrinks(){
25 | 
26 |         Observable<List<? extends Drink>> beerPallets = Observable.create(subscriber -> {
27 | 
28 |             subscriber.onNext(beerStock);   // push the beers pallet
29 | 
30 |             subscriber.onNext(softStock); // push the soft drink pallet
31 | 
32 |             subscriber.onCompleted();
33 |         });
34 | 
35 |         return beerPallets;
36 |     }
37 | 
38 |     public static void main(String[] args) {
39 |         Observable<List<? extends Drink>> pallets = getDrinks();
40 | 
41 |         pallets
42 |             .flatMap(pallet -> Observable.from(pallet))
43 |             .subscribe(
44 |                 data -> System.out.println("Subscriber received " + data),
45 |                 (error) -> System.err.println(error),
46 |                 () -> System.out.println("*** The stream is over ***")
47 |             );
48 |     }
49 | }
50 | 


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/src/main/java/yfain/presentation/rxjava/drink/Beer.java:
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1 | package yfain.presentation.rxjava.drink;
2 | 
3 | public class Beer extends Drink {
4 |     public Beer(String name, String country,float price){
5 |         super(name, country, price);
6 |     }
7 | }
8 | 


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/src/main/java/yfain/presentation/rxjava/drink/Drink.java:
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 1 | package yfain.presentation.rxjava.drink;
 2 | 
 3 | public abstract class Drink {
 4 |     public String name;
 5 |     public String country;
 6 |     public float price;
 7 | 
 8 |     Drink(String name, String country,float price){
 9 |         this.name=name;
10 |         this.country=country;
11 |         this.price=price;
12 |     }
13 | 
14 |     public String toString(){
15 |         return  name + "(" + country + ")";
16 |     }
17 | 
18 | }
19 | 


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/src/main/java/yfain/presentation/rxjava/drink/SoftDrink.java:
--------------------------------------------------------------------------------
1 | package yfain.presentation.rxjava.drink;
2 | 
3 | public class SoftDrink extends Drink{
4 |     public SoftDrink(String name, String country,float price){
5 |         super(name, country, price);
6 |     }
7 | }
8 | 


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/src/main/java/yfain/presentation/rxjava/schedulers/ParallelStreams.java:
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 1 | package yfain.presentation.rxjava.schedulers;
 2 | 
 3 | import rx.schedulers.Schedulers;
 4 | import rx.Observable;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | import yfain.presentation.rxjava.stock.BeerStock;
 7 | 
 8 | import java.util.ArrayList;
 9 | import java.util.List;
10 | 
11 | public class ParallelStreams {
12 |     public static void main(String[] args) {
13 | 
14 |         List<Beer> beers = new BeerStock();  // populate the beer collection
15 | 
16 |         Observable<Beer> observableBeers = Observable.from(beers);
17 | 
18 |         observableBeers
19 |                 .flatMap(beer -> Observable.just(beer)
20 |                                .subscribeOn(Schedulers.computation())  // new thread for each observable
21 |                                .map(ParallelStreams::matureBeer)
22 |                  )
23 | 
24 |                 .subscribe(ParallelStreams::log);
25 | 
26 | 
27 |         // Just to keep the program running
28 |         try {
29 |             Thread.sleep(5000);
30 | 
31 |         } catch (InterruptedException e) {
32 |             e.printStackTrace();
33 |         }
34 |     }
35 | 
36 |     private static void log(Beer beer) {
37 |         System.out.println("Subscriber got " +
38 |                 beer.name + " on  " +
39 |                 Thread.currentThread().getName());
40 |     }
41 | 
42 |     private static Beer matureBeer(Beer beer){
43 |         try {
44 |             System.out.println("** Maturing " + beer.name +
45 |                     " on " + Thread.currentThread().getName());
46 | 
47 |             Thread.sleep((int)(Math.random()*500));
48 |             return beer;
49 | 
50 |         } catch (InterruptedException e) {
51 |             throw new RuntimeException(e);
52 |         }
53 |     }
54 | }
55 | 


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/src/main/java/yfain/presentation/rxjava/schedulers/SubscribeOnObserveOn.java:
--------------------------------------------------------------------------------
 1 | package yfain.presentation.rxjava.schedulers;
 2 | 
 3 | import rx.Observable;
 4 | import rx.schedulers.Schedulers;
 5 | import yfain.presentation.rxjava.drink.Beer;
 6 | import yfain.presentation.rxjava.stock.BeerStock;
 7 | 
 8 | import java.util.List;
 9 | 
10 | public class SubscribeOnObserveOn {
11 | 
12 |     public static void main(String[] args) {
13 | 
14 |         List<Beer> beers = new BeerStock();// populate the beer collection
15 | 
16 |         Observable<Beer> observableBeers = null;
17 | 
18 |         observableBeers.from(beers)
19 |                 .subscribeOn(Schedulers.computation())  // push data on computation thread
20 |                 .doOnNext(SubscribeOnObserveOn::log)            // Side effect: Log on computation thread
21 |                 .observeOn(Schedulers.io())             // Process on another io thread
22 |                 .subscribe(SubscribeOnObserveOn::matureBeer);
23 | 
24 |         // Sleep just to keep the program running
25 |         try {
26 |             Thread.sleep(5000);
27 | 
28 |         } catch (InterruptedException e) {
29 |             e.printStackTrace();
30 |         }
31 | 
32 |     }
33 | 
34 |     private static void matureBeer(Beer beer){
35 |         try {
36 |             System.out.println("** Maturing " + beer.name +
37 |                     " on " + Thread.currentThread().getName());
38 | 
39 |             Thread.sleep((int)(Math.random()*500));
40 | 
41 |         } catch (InterruptedException e) {
42 |             e.printStackTrace();
43 |         }
44 | 
45 |     }
46 | 
47 |     private static void log(Beer beer){
48 |         System.out.println("===> Logging " + beer.name +
49 |                            " on "  + Thread.currentThread().getName() );
50 |     }
51 | }
52 | 


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/src/main/java/yfain/presentation/rxjava/stock/BeerStock.java:
--------------------------------------------------------------------------------
 1 | package yfain.presentation.rxjava.stock;
 2 | 
 3 | import yfain.presentation.rxjava.drink.Beer;
 4 | 
 5 | import java.util.ArrayList;
 6 | 
 7 | /**
 8 |  * Created by ievgenii on 22.02.17.
 9 |  */
10 | public class BeerStock extends ArrayList<Beer> {
11 |     {
12 |         add(new Beer("Obolon", "Ukraine", 4.00f));
13 |         add(new Beer("Stella", "Belgium", 7.75f));
14 |         add(new Beer("Sam Adams", "USA", 7.00f));
15 |         add(new Beer("Bud Light", "USA", 5.00f));
16 |         add(new Beer("Yuengling", "USA", 5.50f));
17 |         add(new Beer("Leffe Blonde", "Belgium", 8.75f));
18 |         add(new Beer("Chimay Blue", "Belgium", 10.00f));
19 |         add(new Beer("Brooklyn Lager", "USA", 8.25f));
20 |     }
21 | }
22 | 


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/src/main/java/yfain/presentation/rxjava/stock/SoftDrinkStock.java:
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 1 | package yfain.presentation.rxjava.stock;
 2 | 
 3 | import yfain.presentation.rxjava.drink.Drink;
 4 | import yfain.presentation.rxjava.drink.SoftDrink;
 5 | 
 6 | import java.util.ArrayList;
 7 | 
 8 | /**
 9 |  * Created by ievgenii on 22.02.17.
10 |  */
11 | public class SoftDrinkStock extends ArrayList<SoftDrink> {
12 |     {
13 |         add(new SoftDrink("Lemonade", "Ukraine", 1.00f));
14 |         add(new SoftDrink("Pepsi", "USA", 2.00f));
15 |         add(new SoftDrink("Fanta", "USA", 3.00f));
16 | 
17 |     }
18 | }
19 | 


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