Completed solution

account-dao/src/main/java/com/bobocode/dao/AccountDaoImpl.java

@@ -1,9 +1,14 @@
 package com.bobocode.dao;
 
+import com.bobocode.exception.AccountDaoException;
 import com.bobocode.model.Account;
 
+import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
+import javax.persistence.TypedQuery;
 import java.util.List;
+import java.util.function.Consumer;
+import java.util.function.Function;
 
 public class AccountDaoImpl implements AccountDao {
     private EntityManagerFactory emf;
@@ -14,32 +19,65 @@ public AccountDaoImpl(EntityManagerFactory emf) {
 
     @Override
     public void save(Account account) {
-        throw new UnsupportedOperationException("I don't wanna work without implementation!"); // todo
+        performWithinPersistenceContext(em -> em.persist(account));
     }
 
     @Override
     public Account findById(Long id) {
-        throw new UnsupportedOperationException("I don't wanna work without implementation!"); // todo
+        return performReturningWithinPersistenceContext(entityManager -> entityManager.find(Account.class, id));
     }
 
     @Override
     public Account findByEmail(String email) {
-        throw new UnsupportedOperationException("I don't wanna work without implementation!"); // todo
+        return performReturningWithinPersistenceContext(entityManager -> {
+            TypedQuery<Account> findByEmailQuery
+                    = entityManager.createQuery("select a from Account a where a.email = :email", Account.class);
+            findByEmailQuery.setParameter("email", email);
+            return findByEmailQuery.getSingleResult();
+        });
     }
 
     @Override
     public List<Account> findAll() {
-        throw new UnsupportedOperationException("I don't wanna work without implementation!"); // todo
+        return performReturningWithinPersistenceContext(entityManager ->
+                entityManager.createQuery("select a from Account a", Account.class).getResultList());
     }
 
     @Override
     public void update(Account account) {
-        throw new UnsupportedOperationException("I don't wanna work without implementation!"); // todo
+        performWithinPersistenceContext(em -> em.merge(account));
     }
 
     @Override
     public void remove(Account account) {
-        throw new UnsupportedOperationException("I don't wanna work without implementation!"); // todo
+        performWithinPersistenceContext(entityManager -> {
+            Account mergedAccount = entityManager.merge(account);
+            entityManager.remove(mergedAccount);
+        });
+    }
+
+    private void performWithinPersistenceContext(Consumer<EntityManager> entityManagerConsumer) {
+        performReturningWithinPersistenceContext(entityManager -> {
+            entityManagerConsumer.accept(entityManager);
+            return null;
+        });
+    }
+
+    private <T> T performReturningWithinPersistenceContext(Function<EntityManager, T> entityManagerFunction) {
+        EntityManager entityManager = emf.createEntityManager();
+        entityManager.getTransaction().begin();
+        T result;
+        try {
+            result = entityManagerFunction.apply(entityManager);
+            entityManager.getTransaction().commit();
+        } catch (Exception e) {
+            entityManager.getTransaction().rollback();
+            throw new AccountDaoException("Error performing dao operation. Transaction is rolled back!", e);
+        } finally {
+            entityManager.close();
+        }
+        return result;
     }
 }
 
+

author-book/src/main/java/com/bobocode/model/Author.java

@@ -1,50 +1,62 @@
 package com.bobocode.model;
 
+import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
-import javax.persistence.CascadeType;
+import javax.persistence.*;
 import java.util.HashSet;
+import java.util.Objects;
 import java.util.Set;
 
-/**
- * todo:
- * - implement no arguments constructor
- * - implement getters and setters for all fields
- * - implement equals() based on identifier field
- * - implement hashCode() that return constant value 31
- * - make setter for field {@link Author#books} private
- * - initialize field {@link Author#books} as new {@link HashSet}
- * - implement a helper {@link Author#addBook(Book)} that establishes a relation on both sides
- * - implement a helper {@link Author#removeBook(Book)} that drops a relation on both sides
- * <p>
- * - configure JPA entity
- * - specify table name: "author"
- * - configure auto generated identifier
- * - configure mandatory column "first_name" for field {@link Author#firstName}
- * - configure mandatory column "last_name" for field {@link Author#lastName}
- * <p>
- * - configure many-to-many relation between {@link Author} and {@link Book}
- * - configure cascade operations for this relations {@link CascadeType#PERSIST} and {@link CascadeType#MERGE}
- * - configure link (join) table "author_book"
- * - configure foreign key column "book_id" references book table
- * - configure foreign key column "author_id" references author table
- */
 @NoArgsConstructor
 @Getter
 @Setter
+@Entity
+@Table(name = "author")
 public class Author {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(name = "first_name", nullable = false)
     private String firstName;
+
+    @Column(name = "last_name", nullable = false)
     private String lastName;
-    private Set<Book> books;
+
+    @Setter(AccessLevel.PRIVATE)
+    @ManyToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE})
+    @JoinTable(name = "author_book",
+            joinColumns = @JoinColumn(name = "author_id"),
+            inverseJoinColumns = @JoinColumn(name = "book_id")
+    )
+    private Set<Book> books = new HashSet<>();
 
     public void addBook(Book book) {
-        throw new UnsupportedOperationException("Are you kidding me?");
+        books.add(book);
+        book.getAuthors().add(this);
     }
 
     public void removeBook(Book book) {
-        throw new UnsupportedOperationException("Are you kidding me?");
+        books.remove(book);
+        book.getAuthors().remove(this);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Author)) return false;
+
+        Author author = (Author) o;
+
+        return Objects.equals(id, author.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return 31;
     }
 }
+

author-book/src/main/java/com/bobocode/model/Book.java

@@ -1,34 +1,32 @@
 package com.bobocode.model;
 
-import lombok.Getter;
-import lombok.NoArgsConstructor;
-import lombok.Setter;
+import lombok.*;
+import org.hibernate.annotations.NaturalId;
 
+import javax.persistence.*;
 import java.util.HashSet;
 import java.util.Set;
 
-/**
- * todo:
- * - implement no arguments constructor
- * - implement getters and setters for all fields
- * - implement equals() and hashCode() based on {@link Book#isbn}
- * - make setter for field {@link Book#authors} private
- * - initialize field {@link Book#authors} as new {@link HashSet}
- * <p>
- * - configure JPA entity
- * - specify table name: "book"
- * - configure auto generated identifier
- * - configure mandatory column "name" for field {@link Book#name}
- * - configure mandatory unique column "isbn" for field {@link Book#isbn}, it is a natural key candidate
- * <p>
- * - configure many-to-many relation as mapped on the {@link Author} side
- */
 @NoArgsConstructor
 @Getter
 @Setter
+@EqualsAndHashCode(of = "isbn")
+@Entity
+@Table(name = "book")
 public class Book {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false)
     private String name;
+
+    @NaturalId
+    @Column(nullable = false, unique = true)
     private String isbn;
-    private Set<Author> authors;
+
+    @Setter(AccessLevel.PRIVATE)
+    @ManyToMany(mappedBy = "books")
+    private Set<Author> authors = new HashSet<>();
 }
+

company-products/src/main/java/com/bobocode/dao/CompanyDaoImpl.java

@@ -1,8 +1,12 @@
 package com.bobocode.dao;
 
+import com.bobocode.exception.CompanyDaoException;
 import com.bobocode.model.Company;
+import org.hibernate.Session;
 
+import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
+import java.util.function.Function;
 
 public class CompanyDaoImpl implements CompanyDao {
     private EntityManagerFactory entityManagerFactory;
@@ -13,6 +17,28 @@ public CompanyDaoImpl(EntityManagerFactory entityManagerFactory) {
 
     @Override
     public Company findByIdFetchProducts(Long id) {
-        throw new UnsupportedOperationException("I'm still not implemented!");
+        return readWithinTx(entityManager ->
+                entityManager
+                        .createQuery("select c from Company c join fetch c.products where c.id = :id", Company.class)
+                        .setParameter("id", id)
+                        .getSingleResult()
+        );
+    }
+
+    private <T> T readWithinTx(Function<EntityManager, T> entityManagerFunction) {
+        EntityManager entityManager = entityManagerFactory.createEntityManager();
+        entityManager.unwrap(Session.class).setDefaultReadOnly(true);
+        entityManager.getTransaction().begin();
+        try {
+            T queryResult = entityManagerFunction.apply(entityManager);
+            entityManager.getTransaction().commit();
+            return queryResult;
+        } catch (Exception e) {
+            entityManager.getTransaction().rollback();
+            throw new CompanyDaoException("Error performing read operation", e);
+        } finally {
+            entityManager.close();
+        }
     }
 }
+

company-products/src/main/java/com/bobocode/model/Company.java

@@ -6,36 +6,31 @@
 import java.util.ArrayList;
 import java.util.List;
 
-/**
- * todo:
- * - implement no arguments constructor
- * - implement getters and setters for all fields
- * - implement equals() and hashCode() based on identifier field
- * - make setter for field {@link Company#products} private
- * - initialize field {@link Company#products} as new {@link ArrayList}
- * - implement a helper {@link Company#addProduct(Product)} that establishes a relation on both sides
- * - implement a helper {@link Company#removeProduct(Product)} that drops a relation on both sides
- * <p>
- * - configure JPA entity
- * - specify table name: "company"
- * - configure auto generated identifier
- * - configure mandatory column "name" for field {@link Company#name}
- * <p>
- * - configure one to many relationship as mapped on the child side
- */
 @NoArgsConstructor
 @Getter
 @Setter
+@EqualsAndHashCode(of = "id")
+@Entity
+@Table(name = "company")
 public class Company {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false)
     private String name;
+
+    @Setter(AccessLevel.PRIVATE)
+    @OneToMany(mappedBy = "company", fetch = FetchType.LAZY)
     private List<Product> products = new ArrayList<>();
 
     public void addProduct(Product product) {
-        throw new UnsupportedOperationException("I'm still not implemented!");
+        products.add(product);
+        product.setCompany(this);
     }
 
     public void removeProduct(Product product) {
-        throw new UnsupportedOperationException("I'm still not implemented!");
+        products.remove(product);
+        product.setCompany(null);
     }
 }

company-products/src/main/java/com/bobocode/model/Product.java

@@ -1,9 +1,12 @@
 package com.bobocode.model;
 
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
+import javax.persistence.*;
+
 /**
  * todo:
  * - implement no arguments constructor
@@ -21,8 +24,18 @@
 @NoArgsConstructor
 @Getter
 @Setter
+@EqualsAndHashCode(of = "id")
+@Entity
+@Table(name = "product")
 public class Product {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false)
     private String name;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "company_id")
     private Company company;
 }

employee-profile/src/main/java/com/bobocode/model/Employee.java

@@ -4,6 +4,8 @@
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
+import javax.persistence.*;
+
 /**
  * todo:
  * - implement no argument constructor
@@ -20,9 +22,20 @@
 @NoArgsConstructor
 @Getter
 @Setter
+@Entity
+@Table(name = "employee")
 public class Employee {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false)
     private String email;
+
+    @Column(nullable = false)
     private String fistName;
+
+    @Column(nullable = false)
     private String lastName;
 }
+

employee-profile/src/main/java/com/bobocode/model/EmployeeProfile.java

@@ -4,25 +4,25 @@
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
-/**
- * todo:
- * - implement not argument constructor
- * - implement getters and setters
- * - implement equals and hashCode based on identifier field
- *
- * - configure JPA entity
- * - specify table name: "employee_profile"
- * - configure not nullable columns: position, department
- *
- * - map relation between {@link Employee} and {@link EmployeeProfile} using foreign_key column: "employee_id"
- * - configure a derived identifier. E.g. map "employee_id" column should be also a primary key (id) for this entity
- */
+import javax.persistence.*;
+
 @NoArgsConstructor
 @Getter
 @Setter
+@Entity
+@Table(name = "employee_profile")
 public class EmployeeProfile {
+    @Id
     private Long id;
+
+    @MapsId
+    @OneToOne
+    @JoinColumn(name = "employee_id")
     private Employee employee;
+
+    @Column(nullable = false)
     private String position;
+
+    @Column(nullable = false)
     private String department;
 }

employee-profile/src/main/resources/META-INF/persistence.xml

@@ -11,7 +11,7 @@
             <property name="hibernate.connection.username" value="bobouser"/>
             <property name="hibernate.connection.password" value="bobopass"/>
             <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
-            <property name="hibernate.show_sql" value="true"/>
+            <property name="hibernate.show_sql" value="false"/>
             <property name="hibernate.format_sql" value="true"/>
             <property name="hibernate.hbm2ddl.auto" value="create"/>
         </properties>

hello-jpa-entity/src/main/java/com/bobocode/model/Movie.java

@@ -4,22 +4,24 @@
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
-/**
- * TODO: you're job is to implement mapping for JPA entity {@link Movie}
- * - specify id
- * - configure id as auto-increment column
- * - explicitly specify each column name ("id", "name", "director", and "duration" accordingly)
- * - specify not null constraint for fields {@link Movie#name} and {@link Movie#director}
- */
+import javax.persistence.*;
+
 @NoArgsConstructor
 @Getter
 @Setter
+@Entity
+@Table(name = "movie")
 public class Movie {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
+    @Column(name = "name", nullable = false)
     private String name;
 
+    @Column(name = "director", nullable = false)
     private String director;
 
+    @Column(name = "duration")
     private Integer durationSeconds;
 }

hello-persistence-xml/src/main/resources/META-INF/persistence.xml

@@ -1,14 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="2.1">
 
-    <!--todo: configure a persistence unit name: TuttiFrutti-->
-    <!--todo: add class Song to this persistence unit-->
-    <!--todo: configure a hibernate connection url for in-memory H2 database-->
-    <!--database name: tutti_frutti_db-->
-    <!--database additional properties: DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false-->
-    <!--todo: configure a hibernate connection username: little_richard-->
-    <!--todo: configure a hibernate connection password: rock_n_roll_is_alive-->
-    <!--todo: configure a hibernate SQL dialect for H2 database-->
-    <!--todo: configure hibernate generate DDL and create database-->
+    <persistence-unit name="TuttiFrutti">
+        <class>com.bobocode.model.Song</class>
+
+        <properties>
+            <property name="hibernate.connection.url" value="jdbc:h2:mem:tutti_frutti_db;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false"/>
+            <property name="hibernate.connection.driver_class" value="org.h2.Driver"/>
+            <property name="hibernate.connection.username" value="little_richard"/>
+            <property name="hibernate.connection.password" value="rock_n_roll_is_alive"/>
+            <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
+            <property name="hibernate.hbm2ddl.auto" value="create"/>
+        </properties>
+    </persistence-unit>
 
 </persistence>

photo-comment-dao/src/main/java/com/bobocode/dao/PhotoDaoImpl.java

@@ -1,42 +1,54 @@
 package com.bobocode.dao;
 
 import com.bobocode.model.Photo;
+import com.bobocode.model.PhotoComment;
+import com.bobocode.util.EntityManagerUtil;
 
 import javax.persistence.EntityManagerFactory;
 import java.util.List;
+import java.util.Objects;
 
-/**
- * Please note that you should not use auto-commit mode for your implementation.
- */
 public class PhotoDaoImpl implements PhotoDao {
-    private EntityManagerFactory entityManagerFactory;
+    private EntityManagerUtil emUtil;
 
     public PhotoDaoImpl(EntityManagerFactory entityManagerFactory) {
-        this.entityManagerFactory = entityManagerFactory;
+        this.emUtil = new EntityManagerUtil(entityManagerFactory);
     }
 
     @Override
     public void save(Photo photo) {
-        throw new UnsupportedOperationException("Just do it!"); // todo
+        Objects.requireNonNull(photo);
+        emUtil.performWithinTx(entityManager -> entityManager.persist(photo));
     }
 
     @Override
     public Photo findById(long id) {
-        throw new UnsupportedOperationException("Just do it!"); // todo
+        return emUtil.performReturningWithinTx(entityManager -> entityManager.find(Photo.class, id));
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public List<Photo> findAll() {
-        throw new UnsupportedOperationException("Just do it!"); // todo
+        return emUtil.performReturningWithinTx(
+                entityManager -> entityManager.createQuery("select p from Photo p").getResultList()
+        );
     }
 
     @Override
     public void remove(Photo photo) {
-        throw new UnsupportedOperationException("Just do it!"); // todo
+        Objects.requireNonNull(photo);
+        emUtil.performWithinTx(entityManager -> {
+            Photo managedPhoto = entityManager.merge(photo);
+            entityManager.remove(managedPhoto);
+        });
     }
 
     @Override
     public void addComment(long photoId, String comment) {
-        throw new UnsupportedOperationException("Just do it!"); // todo
+        emUtil.performWithinTx(entityManager -> {
+            Photo photoReference = entityManager.getReference(Photo.class, photoId);// does not call database
+            PhotoComment photoComment = new PhotoComment(comment, photoReference);
+            entityManager.persist(photoComment);
+        });
     }
 }

photo-comment-dao/src/main/java/com/bobocode/model/Photo.java

@@ -1,8 +1,9 @@
 package com.bobocode.model;
 
-import lombok.Getter;
-import lombok.Setter;
+import lombok.*;
 
+import javax.persistence.*;
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -23,20 +24,35 @@
  * - enable cascade type {@link javax.persistence.CascadeType#ALL} for field {@link Photo#comments}
  * - enable orphan removal
  */
+@NoArgsConstructor
 @Getter
 @Setter
+@EqualsAndHashCode(of = "id")
+@Entity
+@Table(name = "photo")
 public class Photo {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false, unique = true)
     private String url;
+
+    @Column(nullable = false)
     private String description;
-    private List<PhotoComment> comments;
+
+    @Setter(AccessLevel.PRIVATE)
+    @OneToMany(mappedBy = "photo", cascade = CascadeType.ALL, orphanRemoval = true)
+    private List<PhotoComment> comments = new ArrayList<>();
 
     public void addComment(PhotoComment comment) {
-        throw new UnsupportedOperationException("Make me work!");
+        comments.add(comment);
+        comment.setPhoto(this);
     }
 
     public void removeComment(PhotoComment comment) {
-        throw new UnsupportedOperationException("Make me work!");
+        comments.remove(comment);
+        comment.setPhoto(null);
     }
 
 }

photo-comment-dao/src/main/java/com/bobocode/model/PhotoComment.java

@@ -1,8 +1,11 @@
 package com.bobocode.model;
 
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NoArgsConstructor;
 import lombok.Setter;
 
+import javax.persistence.*;
 import java.time.LocalDateTime;
 
 /**
@@ -19,11 +22,31 @@
  * - map relation between Photo and PhotoComment using foreign_key column: "photo_id"
  * - configure relation as mandatory (not optional)
  */
+@NoArgsConstructor
 @Getter
 @Setter
+@EqualsAndHashCode(of = "id")
+@Entity
+@Table(name = "photo_comment")
 public class PhotoComment {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false)
     private String text;
+
+    @Column(nullable = false)
     private LocalDateTime createdOn;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "photo_id")
     private Photo photo;
+
+    public PhotoComment(String text, Photo photo) {
+        this.text = text;
+        this.photo = photo;
+        this.createdOn = LocalDateTime.now();
+    }
 }
+

query-helper/src/main/java/com/bobocode/QueryHelper.java

@@ -31,6 +31,19 @@ public QueryHelper(EntityManagerFactory entityManagerFactory) {
      * @return query result specified by type T
      */
     public <T> T readWithinTx(Function<EntityManager, T> entityManagerConsumer) {
-        throw new UnsupportedOperationException("I'm waiting for you to do your job and make me work ;)"); // todo:
+        EntityManager entityManager = entityManagerFactory.createEntityManager();
+        entityManager.unwrap(Session.class).setDefaultReadOnly(true);
+        entityManager.getTransaction().begin();
+        try {
+            T result = entityManagerConsumer.apply(entityManager);
+            entityManager.getTransaction().commit();
+            return result;
+        } catch (Exception e) {
+            entityManager.getTransaction().rollback();
+            throw new QueryHelperException("Transaction is rolled back.", e);
+        } finally {
+            entityManager.close();
+        }
+
     }
 }