Update Person class and add parallel stream in UsePerson

Updated code in Person.java by adding comments on records and copy constructor. In UsePerson.java, additional code for sequential and parallel streams with maps and peeks were added, enhancing code readability and understanding of process threads. Minor tweaks were also made in the LinkedList's Supplier, BiConsumer syntax.

src/main/java/lambdas/Person.java

@@ -2,6 +2,25 @@
 
 import java.util.Objects;
 
+// Records:
+//  - became GA in Java 16
+//  - immutable data holders
+//  - constructor goes BEFORE the braces
+//  - autogenerate toString(), equals(), hashCode() methods
+//  - "getter" is a method that matches the name of the field, as in "name()"
+
+// public record Person(String name) {
+//     public Person() {
+//         this("Unknown");
+//     }
+//
+//     public Person(String... names) {
+//         this(String.join(" ", names));
+//     }
+// }
+
+
+// POJO: Plain Old Java Object
 public class Person {
     private String name;
 
@@ -11,6 +30,7 @@ public Person(String name) {
         this.name = name;
     }
 
+    // copy constructor
     public Person(Person other) {
         this.name = other.name;
     }

src/main/java/lambdas/UsePerson.java

@@ -22,16 +22,28 @@ public static void main(String[] args) {
                 .collect(Collectors.toList());  // Converts Stream<Person> to List<Person>
         System.out.println(people);
 
+        // Sequential stream
         people = names.stream()
                 .map(Person::new) // uses the Person(String) ctr
+                .peek(person -> System.out.println(person + " processed by " +
+                                                   Thread.currentThread()
+                                                           .getName()))
                 // .map(Person::new) // uses the Person(Person) ctr
                 .collect(Collectors.toList());
         System.out.println(people);
 
+        // Parallel stream
+        people = names.parallelStream()
+                .map(Person::new) // uses the Person(String) ctr
+                .peek(person -> System.out.println(person + " processed by " +
+                                                   Thread.currentThread().getName()))
+                .collect(Collectors.toList());
+        System.out.println(people);
+
         Person[] peopleArray = names.stream()
                 .map(Person::new)
                 .toArray(Person[]::new);
-                //.toArray(value -> new Person[value]);
+        //.toArray(value -> new Person[value]);
         System.out.println(Arrays.toString(peopleArray));
 
         List<String> fullNames = Arrays.asList(
@@ -49,7 +61,7 @@ public static void main(String[] args) {
         LinkedList<Person> linkedPersons = names.stream()
                 .map(Person::new)
                 .collect(
-                        () -> new LinkedList<Person>(),          // Supplier<LinkedList>
+                        () -> new LinkedList<>(),                // Supplier<LinkedList>
                         (list, person) -> list.add(person),      // BiConsumer<LinkedList, Person>
                         (list1, list2) -> list1.addAll(list2));  // BiConsumer<LinkedList, LinkedList>
         System.out.println(linkedPersons);