BAEL-6887: List vs Set in @OneToMany JPA (#15677)

persistence-modules/spring-boot-persistence-4/pom.xml

@@ -42,6 +42,26 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.hypersistence</groupId>
+            <artifactId>hypersistence-utils-hibernate-62</artifactId>
+            <version>${hypersistence-utils.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.vladmihalcea</groupId>
+            <artifactId>db-util</artifactId>
+            <version>${db.util.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -58,6 +78,10 @@
         <junit-jupiter.version>5.9.3</junit-jupiter.version>
         <maven.compiler.source>17</maven.compiler.source>
         <maven.compiler.target>17</maven.compiler.target>
+        <db.util.version>1.0.7</db.util.version>
+        <hypersistence-utils.version>3.7.0</hypersistence-utils.version>
+        <jackson.version>2.16.0</jackson.version>
+        <lombok.version>1.18.28</lombok.version>
     </properties>
 
 </project>

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/ParametrizationAware.java

@@ -0,0 +1,14 @@
+package com.baeldung.listvsset;
+
+import java.lang.reflect.ParameterizedType;
+import java.util.Arrays;
+import java.util.List;
+
+public abstract class ParametrizationAware<T> {
+
+    public List<Class<T>> getParametrizationClass() {
+        ParameterizedType type = (ParameterizedType) this.getClass().getGenericSuperclass();
+        return Arrays.stream(type.getActualTypeArguments())
+          .map(s -> ((Class<T>) s)).toList();
+    }
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/Service.java

@@ -0,0 +1,63 @@
+package com.baeldung.listvsset;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.function.Predicate;
+import java.util.function.ToIntFunction;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.transaction.annotation.Transactional;
+
+@Transactional
+public class Service<S> extends ParametrizationAware<S> {
+
+    private final JpaRepository<S, Long> repository;
+
+    public Service(JpaRepository<S, Long> repository) {
+        this.repository = repository;
+    }
+
+    public JpaRepository<S, Long> getRepository() {
+        return repository;
+    }
+
+    public int countNumberOfRequestsWithFunction(ToIntFunction<List<S>> function) {
+        return function.applyAsInt(repository.findAll());
+    }
+
+
+    public Optional<S> getUserById(Long id) {
+        return repository.findById(id);
+    }
+
+    public void deleteAll() {
+        repository.deleteAll();
+    }
+
+    public List<S> saveAll(Iterable<S> entities) {
+        return repository.saveAll(entities);
+    }
+
+    public List<S> findAll() {
+        return repository.findAll();
+    }
+
+    public Optional<S> getUserByIdWithPredicate(long id, Predicate<S> predicate) {
+        Optional<S> user = repository.findById(id);
+        user.ifPresent(predicate::test);
+        return user;
+    }
+
+    public int getUserByIdWithFunction(Long id, ToIntFunction<S> function) {
+
+        Optional<S> optionalUser = repository.findById(id);
+        if(optionalUser.isPresent()) {
+            return function.applyAsInt(optionalUser.get());
+        } else {
+            return 0;
+        }
+    }
+
+    public void save(S entity) {
+        repository.save(entity);
+    }
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/Application.java

@@ -0,0 +1,8 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/Comment.java

@@ -0,0 +1,25 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import lombok.Data;
+
+@Data
+@Entity
+public class Comment {
+
+    @Id
+    private Long id;
+
+    private String text;
+
+    @ManyToOne
+    private User author;
+
+    @JsonBackReference
+    @ManyToOne
+    private Post post;
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/Group.java

@@ -0,0 +1,23 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToMany;
+import jakarta.persistence.Table;
+import java.util.List;
+import lombok.Data;
+
+@Data
+@Entity(name = "interest_group")
+@Table(name = "interest_group")
+public class Group {
+
+    @Id
+    private Long id;
+
+    private String name;
+
+    @ManyToMany(fetch = FetchType.EAGER)
+    private List<User> members;
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/Post.java

@@ -0,0 +1,32 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+import com.fasterxml.jackson.annotation.JsonManagedReference;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Lob;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import java.util.List;
+import lombok.Data;
+
+@Entity
+@Data
+public class Post {
+
+    @Id
+    private Long id;
+
+    @Lob
+    private String content;
+
+    @JsonManagedReference
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "post", fetch = FetchType.EAGER)
+    private List<Comment> comments;
+
+    @JsonBackReference
+    @ManyToOne
+    private User author;
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/PostRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PostRepository extends JpaRepository<Post, Long> {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/Profile.java

@@ -0,0 +1,28 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.Lob;
+import jakarta.persistence.OneToOne;
+import lombok.Data;
+
+@Entity
+@Data
+public class Profile {
+
+    @Id
+    private Long id;
+
+    @Lob
+    private String biography;
+    private String website;
+    private String profilePictureUrl;
+
+    @JsonBackReference
+    @OneToOne(mappedBy = "profile")
+    @JoinColumn(unique = true)
+    private User user;
+}
+

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/User.java

@@ -0,0 +1,36 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import com.fasterxml.jackson.annotation.JsonManagedReference;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToMany;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.OneToOne;
+import jakarta.persistence.Table;
+import java.util.List;
+import lombok.Data;
+
+@Data
+@Entity(name = "simple_user")
+@Table(name = "simple_user")
+public class User {
+
+    @Id
+    private Long id;
+    private String username;
+    private String email;
+
+    @JsonManagedReference
+    @OneToOne(cascade = CascadeType.ALL)
+    private Profile profile;
+
+    @JsonManagedReference
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "author", fetch = FetchType.EAGER)
+    protected List<Post> posts;
+
+
+    @ManyToMany(mappedBy = "members", fetch = FetchType.EAGER)
+    private List<Group> groups;
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/UserRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface UserRepository extends JpaRepository<User, Long> {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/fulldomain/UserService.java

@@ -0,0 +1,20 @@
+package com.baeldung.listvsset.eager.list.fulldomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Transactional
+@Service
+public class UserService extends com.baeldung.listvsset.Service<User> {
+
+    public UserService(JpaRepository<User, Long> repository) {
+        super(repository);
+    }
+
+    @Override
+    public UserRepository getRepository() {
+        return ((UserRepository) super.getRepository());
+    }
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/Application.java

@@ -0,0 +1,8 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/Group.java

@@ -0,0 +1,23 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToMany;
+import jakarta.persistence.Table;
+import java.util.List;
+import lombok.Data;
+
+@Data
+@Entity(name = "interest_group")
+@Table(name = "interest_group")
+public class Group {
+
+    @Id
+    private Long id;
+
+    private String name;
+
+    @ManyToMany(fetch = FetchType.EAGER)
+    private List<User> members;
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/GroupRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface GroupRepository extends JpaRepository<Group, Long> {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/GroupService.java

@@ -0,0 +1,29 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import java.util.List;
+import java.util.Optional;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class GroupService {
+
+    private final GroupRepository groupRepository;
+
+    @Autowired
+    public GroupService(GroupRepository groupRepository) {
+        this.groupRepository = groupRepository;
+    }
+
+    public Optional<Group> findById(Long aLong) {
+        return groupRepository.findById(aLong);
+    }
+
+    public List<Group> findAll() {
+        return groupRepository.findAll();
+    }
+
+    public <S extends Group> S save(S entity) {
+        return groupRepository.save(entity);
+    }
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/Post.java

@@ -0,0 +1,23 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Lob;
+import jakarta.persistence.ManyToOne;
+import lombok.Data;
+
+@Entity
+@Data
+public class Post {
+
+    @Id
+    private Long id;
+
+    @Lob
+    private String content;
+
+    @JsonBackReference
+    @ManyToOne
+    private User author;
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/PostRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PostRepository extends JpaRepository<Post, Long> {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/User.java

@@ -0,0 +1,46 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import com.fasterxml.jackson.annotation.JsonManagedReference;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+import java.util.List;
+import java.util.Objects;
+import lombok.Data;
+
+@Data
+@Entity(name = "simple_user")
+@Table(name = "simple_user")
+public class User {
+
+    @Id
+    private Long id;
+    private String username;
+    private String email;
+
+    @JsonManagedReference
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "author", fetch = FetchType.EAGER)
+    protected List<Post> posts;
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        User user = (User) o;
+
+        return Objects.equals(id, user.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return id != null ? id.hashCode() : 0;
+    }
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/UserRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface UserRepository extends JpaRepository<User, Long> {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/moderatedomain/UserService.java

@@ -0,0 +1,20 @@
+package com.baeldung.listvsset.eager.list.moderatedomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Transactional
+@Service
+public class UserService extends com.baeldung.listvsset.Service<User> {
+
+    public UserService(JpaRepository<User, Long> repository) {
+        super(repository);
+    }
+
+    @Override
+    public UserRepository getRepository() {
+        return ((UserRepository) super.getRepository());
+    }
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/simpledomain/Application.java

@@ -0,0 +1,8 @@
+package com.baeldung.listvsset.eager.list.simpledomain;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/simpledomain/Post.java

@@ -0,0 +1,23 @@
+package com.baeldung.listvsset.eager.list.simpledomain;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Lob;
+import jakarta.persistence.ManyToOne;
+import lombok.Data;
+
+@Entity
+@Data
+public class Post {
+
+    @Id
+    private Long id;
+
+    @Lob
+    private String content;
+
+    @JsonBackReference
+    @ManyToOne
+    private User author;
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/simpledomain/PostRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.listvsset.eager.list.simpledomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PostRepository extends JpaRepository<Post, Long> {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/simpledomain/User.java

@@ -0,0 +1,26 @@
+package com.baeldung.listvsset.eager.list.simpledomain;
+
+import com.fasterxml.jackson.annotation.JsonManagedReference;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+import java.util.List;
+import lombok.Data;
+
+@Data
+@Entity(name = "simple_user")
+@Table(name = "simple_user")
+public class User {
+
+    @Id
+    private Long id;
+    private String username;
+    private String email;
+
+    @JsonManagedReference
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "author", fetch = FetchType.EAGER)
+    protected List<Post> posts;
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/simpledomain/UserRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.listvsset.eager.list.simpledomain;
+
+import org.springframework.context.annotation.Lazy;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+@Lazy(value = false)
+public interface UserRepository extends JpaRepository<User, Long> {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/list/simpledomain/UserService.java

@@ -0,0 +1,20 @@
+package com.baeldung.listvsset.eager.list.simpledomain;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Transactional
+@Service
+public class UserService extends com.baeldung.listvsset.Service<User> {
+
+    public UserService(JpaRepository<User, Long> repository) {
+        super(repository);
+    }
+
+    @Override
+    public UserRepository getRepository() {
+        return ((UserRepository) super.getRepository());
+    }
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/set/fulldomain/Application.java

@@ -0,0 +1,8 @@
+package com.baeldung.listvsset.eager.set.fulldomain;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/set/fulldomain/Comment.java

@@ -0,0 +1,44 @@
+package com.baeldung.listvsset.eager.set.fulldomain;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import java.util.Objects;
+import lombok.Data;
+
+@Data
+@Entity
+public class Comment {
+
+    @Id
+    private Long id;
+
+    private String text;
+
+    @ManyToOne
+    private User author;
+
+    @JsonBackReference
+    @ManyToOne
+    private Post post;
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        Comment comment = (Comment) o;
+
+        return Objects.equals(id, comment.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return id != null ? id.hashCode() : 0;
+    }
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/listvsset/eager/set/fulldomain/Group.java

@@ -0,0 +1,43 @@
+package com.baeldung.listvsset.eager.set.fulldomain;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToMany;
+import jakarta.persistence.Table;
+import java.util.Objects;
+import java.util.Set;
+import lombok.Data;
+
+@Data
+@Entity(name = "interest_group")
+@Table(name = "interest_group")
+public class Group {
+
+    @Id
+    private Long id;
+
+    private String name;
+
+    @ManyToMany(fetch = FetchType.EAGER)
+    private Set<User> members;
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        Group group = (Group) o;
+
+        return Objects.equals(id, group.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return id != null ? id.hashCode() : 0;
+    }
+}