RxJava Vertx refactor (#2531)

* Refactor

* Refactor

vertx-and-rxjava/pom.xml

@@ -10,7 +10,6 @@
     </parent>
 
     <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
     <artifactId>vertx-and-rxjava</artifactId>
 
     <build>

vertx-and-rxjava/src/test/java/com/baeldung/VertxWithRxJavaTest.java

@@ -1,94 +0,0 @@
-package com.baeldung;
-
-import io.reactivex.Flowable;
-import io.vertx.reactivex.core.Vertx;
-import io.vertx.reactivex.core.buffer.Buffer;
-import io.vertx.reactivex.core.file.FileSystem;
-import io.vertx.reactivex.core.http.HttpClient;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.time.ZonedDateTime;
-
-import static com.baeldung.MetaWeatherClient.getDataByPlaceId;
-import static com.baeldung.MetaWeatherClient.searchByCityName;
-
-public class VertxWithRxJavaTest {
-
-    private Vertx vertx;
-    private HttpClient httpClient;
-    private FileSystem fileSystem;
-    static Logger log = LoggerFactory.getLogger(VertxWithRxJavaTest.class);
-
-    @Before public void setUp() {
-        vertx = io.vertx.reactivex.core.Vertx.vertx();
-        httpClient = vertx.createHttpClient();
-        fileSystem = vertx.fileSystem();
-    }
-
-    @After public void tearDown() {
-        vertx.close();
-    }
-
-    @Test public void lightLengthTest() throws InterruptedException {
-
-        // read the file that contains one city name per line
-        fileSystem
-                .rxReadFile("cities.txt").toFlowable()
-                .doOnNext(buffer -> log.info("File buffer ---\n{}\n---", buffer))
-
-                // split file content in lines to obtain one city per line
-                .flatMap(buffer -> Flowable.fromArray(buffer.toString().split("\\r?\\n")))
-                .doOnNext(city -> log.info("City from file: '{}'", city))
-
-                // discard cities that are commented out with a leading '#'
-                .filter(city -> !city.startsWith("#"))
-                .doOnNext(city -> log.info("City that survived filtering: '{}'", city))
-
-                // for each city sends a request to obtain its 'woeid'
-                // and collect the buffer from the answer
-                .flatMap(city -> searchByCityName(httpClient, city) )
-                .flatMap(response -> response.toFlowable())
-                .doOnNext(buffer -> log.info("JSON of city detail: '{}'", buffer))
-
-                // get the woeid of each city
-                .map(cityBuffer -> cityBuffer
-                        .toJsonArray()
-                        .getJsonObject(0)
-                        .getLong("woeid"))
-
-                // use the id to ask for data
-                .flatMap(cityId -> getDataByPlaceId(httpClient, cityId))
-                .flatMap(response -> response
-                        .toObservable()
-                        .reduce(
-                                Buffer.buffer(),
-                                (total, newBuf) -> total.appendBuffer( newBuf )).toFlowable() )
-
-                // get the JSON object out of the response
-                .doOnNext(buffer -> log.info("JSON of place detail: '{}'", buffer))
-                .map(buffer -> buffer.toJsonObject())
-
-                // map the JSON in a POJO
-                .map(json -> {
-                    ZonedDateTime sunRise = ZonedDateTime.parse(json.getString("sun_rise"));
-                    ZonedDateTime sunSet = ZonedDateTime.parse(json.getString("sun_set"));
-                    String cityName = json.getString("title");
-                    return new CityAndDayLength(
-                        cityName,sunSet.toEpochSecond() - sunRise.toEpochSecond());
-                })
-
-                // consume the events
-                .subscribe(
-                    cityAndDayLength -> System.out.println(cityAndDayLength),
-                    ex -> ex.printStackTrace());
-
-        // enough to give time to complete the execution
-        Thread.sleep(20000);
-
-    }
-
-}

vertx-and-rxjava/src/test/java/com/baeldung/weather/CityAndDayLength.java

@@ -1,4 +1,4 @@
-package com.baeldung;
+package com.baeldung.weather;
 
 import java.text.MessageFormat;
 
@@ -7,12 +7,13 @@ class CityAndDayLength {
     private final String city;
     private final double dayLengthInHours;
 
-    public CityAndDayLength(String city, long dayLengthInSeconds) {
+    CityAndDayLength(String city, long dayLengthInSeconds) {
         this.city = city;
         this.dayLengthInHours = dayLengthInSeconds / (60.0 * 60.0);
     }
 
-    @Override public String toString() {
+    @Override
+    public String toString() {
         return MessageFormat.format("In {0} there are {1,number,#0.0} hours of light.", city, dayLengthInHours);
     }
 }

vertx-and-rxjava/src/test/java/com/baeldung/weather/MetaWeatherClient.java

@@ -1,4 +1,4 @@
-package com.baeldung;
+package com.baeldung.weather;
 
 import io.reactivex.Flowable;
 import io.vertx.core.http.RequestOptions;
@@ -8,7 +8,7 @@ import io.vertx.reactivex.core.http.HttpClientResponse;
 
 import static java.lang.String.format;
 
-public class MetaWeatherClient {
+class MetaWeatherClient {
 
     private static RequestOptions metawether = new RequestOptions()
       .setHost("www.metaweather.com")
@@ -18,13 +18,13 @@ public class MetaWeatherClient {
     /**
      * @return A flowable backed by vertx that automatically sends an HTTP request at soon as the first subscription is received.
      */
-private static Flowable<HttpClientResponse> autoPerformingReq(HttpClient httpClient, String uri) {
+    private static Flowable<HttpClientResponse> autoPerformingReq(HttpClient httpClient, String uri) {
         HttpClientRequest req = httpClient.get(new RequestOptions(metawether).setURI(uri));
         return req.toFlowable()
           .doOnSubscribe(subscription -> req.end());
-}
+    }
 
-static Flowable<HttpClientResponse> searchByCityName(HttpClient httpClient, String cityName) {
+    static Flowable<HttpClientResponse> searchByCityName(HttpClient httpClient, String cityName) {
         HttpClientRequest req = httpClient.get(
           new RequestOptions()
             .setHost("www.metaweather.com")
@@ -34,7 +34,7 @@ static Flowable<HttpClientResponse> searchByCityName(HttpClient httpClient, Stri
         return req
           .toFlowable()
           .doOnSubscribe(subscription -> req.end());
-}
+    }
 
     static Flowable<HttpClientResponse> getDataByPlaceId(HttpClient httpClient, long placeId) {
         return autoPerformingReq(

vertx-and-rxjava/src/test/java/com/baeldung/weather/VertxWithRxJavaTest.java

@@ -0,0 +1,92 @@
+package com.baeldung.weather;
+
+import io.reactivex.Flowable;
+import io.reactivex.functions.Function;
+import io.vertx.core.json.JsonObject;
+import io.vertx.reactivex.core.Vertx;
+import io.vertx.reactivex.core.buffer.Buffer;
+import io.vertx.reactivex.core.file.FileSystem;
+import io.vertx.reactivex.core.http.HttpClient;
+import io.vertx.reactivex.core.http.HttpClientResponse;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.reactivestreams.Publisher;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.time.ZonedDateTime;
+
+import static com.baeldung.weather.MetaWeatherClient.getDataByPlaceId;
+import static com.baeldung.weather.MetaWeatherClient.searchByCityName;
+
+public class VertxWithRxJavaTest {
+
+    private Vertx vertx;
+    private HttpClient httpClient;
+    private FileSystem fileSystem;
+    private static Logger log = LoggerFactory.getLogger(VertxWithRxJavaTest.class);
+
+    @Before
+    public void setUp() {
+        vertx = io.vertx.reactivex.core.Vertx.vertx();
+        httpClient = vertx.createHttpClient();
+        fileSystem = vertx.fileSystem();
+    }
+
+    @After
+    public void tearDown() {
+        vertx.close();
+    }
+
+    @Test
+    public void shouldDisplayLightLenghts() throws InterruptedException {
+
+        // read the file that contains one city name per line
+        fileSystem
+          .rxReadFile("cities.txt").toFlowable()
+          .doOnNext(buffer -> log.info("File buffer ---\n{}\n---", buffer))
+          .flatMap(buffer -> Flowable.fromArray(buffer.toString().split("\\r?\\n")))
+          .doOnNext(city -> log.info("City from file: '{}'", city))
+          .filter(city -> !city.startsWith("#"))
+          .doOnNext(city -> log.info("City that survived filtering: '{}'", city))
+          .flatMap(city -> searchByCityName(httpClient, city))
+          .flatMap(HttpClientResponse::toFlowable)
+          .doOnNext(buffer -> log.info("JSON of city detail: '{}'", buffer))
+          .map(extractingWoeid())
+          .flatMap(cityId -> getDataByPlaceId(httpClient, cityId))
+          .flatMap(toBufferFlowable())
+          .doOnNext(buffer -> log.info("JSON of place detail: '{}'", buffer))
+          .map(Buffer::toJsonObject)
+          .map(toCityAndDayLength())
+          .subscribe(System.out::println, Throwable::printStackTrace);
+
+        Thread.sleep(20000);  // enough to give time to complete the execution
+    }
+
+    private static Function<HttpClientResponse, Publisher<? extends Buffer>> toBufferFlowable() {
+        return response -> response
+          .toObservable()
+          .reduce(
+            Buffer.buffer(),
+            Buffer::appendBuffer).toFlowable();
+    }
+
+    private static Function<Buffer, Long> extractingWoeid() {
+        return cityBuffer -> cityBuffer
+          .toJsonArray()
+          .getJsonObject(0)
+          .getLong("woeid");
+    }
+
+    private static Function<JsonObject, CityAndDayLength> toCityAndDayLength() {
+        return json -> {
+            ZonedDateTime sunRise = ZonedDateTime.parse(json.getString("sun_rise"));
+            ZonedDateTime sunSet = ZonedDateTime.parse(json.getString("sun_set"));
+            String cityName = json.getString("title");
+            return new CityAndDayLength(
+              cityName, sunSet.toEpochSecond() - sunRise.toEpochSecond());
+        };
+    }
+
+}