class 26 29 Streams advanced methods

Author: MartinFiorde

modules/src/main/java/com/platzi/functional_student_practice/_15_streams/C23Y24Streams.java

@@ -1,6 +1,6 @@
 package com.platzi.functional_student_practice._15_streams;
 
-import com.platzi.functional_teacher_theory._06_reference_operator.NombresUtils;
+import com.platzi.functional_teacher_theory.util.Utils;
 
 import java.util.Collections;
 import java.util.List;
@@ -13,7 +13,7 @@ public static void main(String[] args) {
         System.out.println("\nCLASS 23\n");
 
         // 1. forma comun de trabajar sobre listas, strings y collections
-        List<String> courseList = NombresUtils.getList("Java!", "JavaScript", "FrontEnd", "Backend", "FullStack");
+        List<String> courseList = Utils.getListOf("Java!", "JavaScript", "FrontEnd", "Backend", "FullStack");
         for (String course : Collections.unmodifiableList(courseList)) {
             String newCourseName = course.toLowerCase().replace("!", "!!!");
             System.out.println("1. Cursos bucle sobre lista: " + newCourseName);

modules/src/main/java/com/platzi/functional_student_practice/_15_streams/C26Y29TypeStream.java

@@ -0,0 +1,41 @@
+package com.platzi.functional_student_practice._15_streams;
+
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class C26Y29TypeStream {
+    public static void main(String[] args) {
+        System.out.println("\n////////////////////////////////////////////////////////////////////////////////////");
+        System.out.println("\nCLASS 26\n");
+
+        IntStream infiniteStream = IntStream.iterate(0, x -> x + 1); //se genera un stream infinito
+        IntStream limitedStream = infiniteStream.limit(1000); // se limita el stream para poder trabajarlo
+        boolean isAllEven = limitedStream
+                .filter(x -> x % 2 == 0)
+                .allMatch(x -> x % 2 == 0); // valida que todos los elementos cumplan con una condición. util para validar existencia de datos, limites, etc
+        System.out.println("all even? " + isAllEven);
+
+        IntStream infiniteStream2 = IntStream.iterate(0, x -> x + 1);
+        System.out.println("paralel sum: "+infiniteStream2
+                .limit(1000000)
+                .parallel() // sirve para distribuir todos los calculos del stream distribuidos automaticamente en todos los procesadores del equipo
+                .filter(x -> x % 2 == 0)
+                .reduce(0, Integer::sum));
+
+        System.out.println("\n////////////////////////////////////////////////////////////////////////////////////");
+        System.out.println("\nCLASS 29\n");
+
+        String pairNumbersAsIndividualString = IntStream.iterate(0, x -> x + 1)
+                .limit(1000)
+                .filter(x -> x % 2 == 0)
+                .boxed() // transforma el IntStream a un Stream<Integer>
+                .map(Object::toString) // transformamos a un Stream<String> para poder aplicar el map siguiente
+                .collect(Collectors.joining(",","[","]")); // transformamos el stream para que entregue un String con todos los datos separados con "," entre corchetes
+        System.out.println("List as collected individual String: " + pairNumbersAsIndividualString);
+        String[] listAsStrings = pairNumbersAsIndividualString.substring(1, pairNumbersAsIndividualString.length() - 2).split(",");
+        System.out.println("count: " + Stream.of(listAsStrings).count());
+        System.out.println("sum: " + Stream.of(listAsStrings).map(Integer::valueOf).reduce(0, Integer::sum));
+
+    }
+}

modules/src/main/java/com/platzi/functional_teacher_theory/util/Utils.java

@@ -4,6 +4,9 @@
 import java.util.List;
 
 public class Utils {
+    private Utils() {
+    }
+
     @SafeVarargs
     public static <T> List<T> getListOf(T... items) {
         return Arrays.asList(items);