stream module

kodilla-stream/build.gradle

@@ -0,0 +1,19 @@
+plugins {
+    id 'java'
+}
+
+group = 'com.kodilla'
+version = '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation platform('org.junit:junit-bom:5.10.0')
+    testImplementation 'org.junit.jupiter:junit-jupiter'
+}
+
+test {
+    useJUnitPlatform()
+}

kodilla-stream/src/main/java/com/kodilla/stream/User.java

@@ -0,0 +1,46 @@
+package com.kodilla.stream;
+
+import java.util.Objects;
+
+public class User {
+    private String username;
+    private int age;
+    private int numberOfPost;
+    private String group;
+
+    public User(String username, int age, int numberOfPost, String group) {
+        this.username = username;
+        this.age = age;
+        this.numberOfPost = numberOfPost;
+        this.group = group;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public int getNumberOfPost() {
+        return numberOfPost;
+    }
+
+    public String getGroup() {
+        return group;
+    }
+
+    @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 && numberOfPost == user.numberOfPost && Objects.equals(username, user.username) && Objects.equals(group, user.group);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(username, age, numberOfPost, group);
+    }
+}

kodilla-stream/src/main/java/com/kodilla/stream/UsersManager.java

@@ -0,0 +1,39 @@
+package com.kodilla.stream;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class UsersManager {
+    public static void main(String[] args) {
+        List<String> chemistGroupUsernames = filterChemistGroupUsernames();
+        System.out.println(chemistGroupUsernames);
+    }
+
+    public static List<String> filterChemistGroupUsernames() {
+        List<String> usernames = UsersRepository.getUsersList()
+                .stream()
+                .filter(user -> user.getGroup().equals("Chemists"))
+                .map(UsersManager::getUserName)
+                .collect(Collectors.toList());
+
+        return usernames;
+    }
+
+    public static List<User> filterAboveGivenAge(int givenAge) {
+        return UsersRepository.getUsersList()
+                .stream()
+                .filter(user -> user.getAge() > givenAge)
+                .collect(Collectors.toList());
+    }
+
+    public static List<User> filterBelowPostLimit(int postLimit) {
+        return UsersRepository.getUsersList()
+                .stream()
+                .filter(user -> user.getNumberOfPost() < postLimit)
+                .collect(Collectors.toList());
+    }
+
+    public static String getUserName(User user) {
+        return user.getUsername();
+    }
+}

kodilla-stream/src/main/java/com/kodilla/stream/UsersRepository.java

@@ -0,0 +1,17 @@
+package com.kodilla.stream;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class UsersRepository {
+    public static List<User> getUsersList() {
+        List<User> users = new ArrayList<>();
+        users.add(new User("Walter White", 50, 7, "Chemists"));
+        users.add(new User("Jessie Pinkman", 25, 4648, "Sales"));
+        users.add(new User("Tuco Salamanca", 34, 116, "Manager"));
+        users.add(new User("Gus Fring", 49, 0, "Board"));
+        users.add(new User("Gale Boetticher", 44, 2, "Chemists"));
+        users.add(new User("Mike Ehrmantraut", 57, 0, "Security"));
+        return users;
+    }
+}

kodilla-stream/src/test/java/com/kodilla/stream/UsersManagerTest.java

@@ -0,0 +1,35 @@
+package com.kodilla.stream;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class UsersManagerTest {
+    @Test
+    public void testFilterChemistGroupUsernames() {
+        List<String> actualChemists = UsersManager.filterChemistGroupUsernames();
+        List<String> expectedChemists = new ArrayList<>(Arrays.asList("Gale Boetticher", "Walter White"));
+
+        assertTrue(expectedChemists.containsAll(actualChemists));
+        assertTrue(actualChemists.containsAll(expectedChemists));
+        assertEquals(actualChemists.size(), expectedChemists.size());
+    }
+
+    @Test
+    public void testFilterAboveGivenAge() {
+        List<User> usersAboveGivenAge = UsersManager.filterAboveGivenAge(35);
+
+        assertTrue(usersAboveGivenAge.stream().allMatch(user -> user.getAge() > 35));
+    }
+
+    @Test
+    public void testFilterBelowPostLimit() {
+        List<User> usersBelowPostLimit = UsersManager.filterBelowPostLimit(100);
+
+        assertTrue(usersBelowPostLimit.stream().allMatch(user -> user.getNumberOfPost() < 100));
+    }
+}

settings.gradle

@@ -4,4 +4,5 @@ include 'kodilla-basic-tests'
 include 'kodilla-collections'
 include 'kodilla-collections'
 include 'kodilla-collections-advanced'
+include 'kodilla-stream'