added code of collections-vs-stream

persistence-modules/spring-data-jpa-query-3/pom.xml

@@ -22,6 +22,11 @@
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.github.javafaker</groupId>
+            <artifactId>javafaker</artifactId>
+            <version>0.15</version>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>

persistence-modules/spring-data-jpa-query-3/src/main/java/com/baeldung/spring/data/jpa/collections/vsstream/User.java

@@ -0,0 +1,61 @@
+package com.baeldung.spring.data.jpa.collections.vsstream;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "_user")
+public class User {
+    private String firstName;
+    private String lastName;
+    private int age;
+    @Id
+    private int id;
+
+    public User() {
+    }
+
+    public User(String firstName, String lastName, int age) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.age = age;
+    }
+
+    public User(String firstName, String lastName, int age, int id) {
+        this(firstName, lastName, age);
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+}

persistence-modules/spring-data-jpa-query-3/src/main/java/com/baeldung/spring/data/jpa/collections/vsstream/UserRepository.java

@@ -0,0 +1,14 @@
+package com.baeldung.spring.data.jpa.collections.vsstream;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UserRepository extends JpaRepository<User, String> {
+  Stream<User> findAllByAgeGreaterThan(int age);
+
+  List<User> findByAgeGreaterThan(int age);
+}

persistence-modules/spring-data-jpa-query-3/src/test/java/com/baeldung/spring/data/jpa/query/collections/vsstream/UserRepositoryIntegrationTest.java

@@ -0,0 +1,41 @@
+package com.baeldung.spring.data.jpa.query.collections.vsstream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.data.jdbc.DataJdbcTest;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.baeldung.spring.data.jpa.collections.vsstream.User;
+import com.baeldung.spring.data.jpa.collections.vsstream.UserRepository;
+
+@DataJpaTest
+class UserRepositoryIntegrationTest {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Test
+    public void whenAgeIs20_thenItShouldReturnAllUsersWhoseAgeIsGreaterThan20InAList() {
+        List<User> users = userRepository.findByAgeGreaterThan(20);
+        assertThat(users).isNotEmpty();
+        assertThat(users.stream()
+          .map(User::getAge)
+          .allMatch(age -> age > 20)).isTrue();
+    }
+
+    @Test
+    @Transactional
+    public void whenAgeIs20_thenItShouldReturnAllUsersWhoseAgeIsGreaterThan20InAStream() {
+        Stream<User> users = userRepository.findAllByAgeGreaterThan(20);
+        assertThat(users).isNotNull();
+        assertThat(users.map(User::getAge)
+          .allMatch(age -> age > 20)).isTrue();
+    }
+}