Cities

src/main/java/com/oracle/dao/InMemoryWorldDao.java

@@ -143,6 +143,7 @@ public void createCities1() {
         cities.put(127, new City(127, "Gjumri", "ARM", 211700));
         cities.put(128, new City(128, "Vanadzor", "ARM", 172700));
         cities.put(129, new City(129, "Oranjestad", "ABW", 29034));
+
         cities.put(130, new City(130, "Sydney", "AUS", 3276207));
         cities.put(131, new City(131, "Melbourne", "AUS", 2865329));
         cities.put(132, new City(132, "Brisbane", "AUS", 1291117));
@@ -157,6 +158,7 @@ public void createCities1() {
         cities.put(141, new City(141, "Geelong", "AUS", 125382));
         cities.put(142, new City(142, "Townsville", "AUS", 109914));
         cities.put(143, new City(143, "Cairns", "AUS", 92273));
+
         cities.put(144, new City(144, "Baku", "AZE", 1787800));
         cities.put(145, new City(145, "G„nc„", "AZE", 299300));
         cities.put(146, new City(146, "Sumqayit", "AZE", 283000));

src/main/java/com/oracle/stream/CountriesAndCities.java

@@ -1,14 +1,38 @@
 package com.oracle.stream;
 
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.Set;
+
 import com.oracle.dao.CityDao;
 import com.oracle.dao.CountryDao;
 import com.oracle.dao.InMemoryWorldDao;
+import com.oracle.domain.City;
+import com.oracle.domain.Country;
 
 public class CountriesAndCities {
     private static final CountryDao countryDao = InMemoryWorldDao.getInstance();
     private static final CityDao cityDao = InMemoryWorldDao.getInstance();
 
     public static void main(String[] args) {
         // Encontrar las ciudades mas pobladas en cada continente
+        // 1.- Obtengo continentes
+        // 2.-Obtengo los paises por continentes
+        // 3.-La ciudad más poblada de cada país
+        // 4.-Busco la ciudad más poblada de ese continente
+        try {            
+            countryDao.getAllContinents().stream().forEach(c -> {
+                System.out.println("Continente");
+                System.out.println(c);
+                System.out.println(
+                countryDao.findCountriesByContinent(c).stream().map(pais ->
+                    cityDao.findCitiesByCountryCode(pais.getCode()).stream().map(ciudad-> ciudad.getPopulation()).max(Comparator.naturalOrder())
+                ).map(p -> p.isPresent() ? p.get() : 0).max(Comparator.naturalOrder()).get());
+            });
+        } catch (NoSuchElementException e) {
+            System.out.println("");
+        }
     }
 }

src/main/java/com/oracle/stream/StreamEjemplo.java

@@ -16,9 +16,9 @@ public static void main(String[] args) {
         personList.add(new Person("Alisa", 7900, 26, "female", "New York"));
 
         // Crear una nueva persona y agregarla a la lista
-        List<Person> personList2 = personList.stream().map().collect(Collectors.toList());
+        //List<Person> personList2 = personList.stream().map().collect(Collectors.toList());
         // Convertir km a millas
-        List<Person> personList3 = personList2.stream().map().collect(Collectors.toList());
+        //List<Person> personList3 = personList2.stream().map().collect(Collectors.toList());
     }
 }