6.19. Промежуточные операции. Метод distinct(). Уникальные объекты

src/main/java/ru/job4j/stream/DistinctForObject.java

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+package ru.job4j.stream;
+
+import java.util.List;
+import java.util.Objects;
+
+public class DistinctForObject {
+
+    public static class User {
+        private final String name;
+        private final int age;
+
+        public User(String name, int age) {
+            this.name = name;
+            this.age = age;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (o == null || getClass() != o.getClass()) {
+                return false;
+            }
+            User user = (User) o;
+            return age == user.age && Objects.equals(name, user.name);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(name, age);
+        }
+    }
+
+    public static List<User> distinct(List<User> users) {
+        return users.stream()
+                .distinct()
+                .toList();
+    }
+}

src/test/java/ru/job4j/stream/DistinctForObjectTest.java

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+package ru.job4j.stream;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class DistinctForObjectTest {
+
+    @Test
+    public void test() {
+        DistinctForObject.User user1 = new DistinctForObject.User("A", 20);
+        DistinctForObject.User user2 = new DistinctForObject.User("B", 20);
+        DistinctForObject.User user3 = new DistinctForObject.User("A", 21);
+        DistinctForObject.User user4 = new DistinctForObject.User("A", 20);
+        assertEquals(
+                List.of(user1, user2, user3),
+                DistinctForObject.distinct(List.of(
+                        user1, user2, user3, user4
+                ))
+        );
+    }
+
+}