all tests are passed

pom.xml

@@ -38,6 +38,7 @@
             <artifactId>spring-core</artifactId>
             <version>5.1.5.RELEASE</version>
         </dependency>
+
     </dependencies>
 
     <build>

src/main/java/com/epam/izh/rd/online/entity/Author.java

@@ -20,4 +20,74 @@
  */
 public class Author {
 
+    private String name;
+    private String lastName;
+    private LocalDate birthdate;
+    private String country;
+
+    public Author() {
+    }
+
+    public Author(String name, String lastName, LocalDate birthdate, String country) {
+        this.name = name;
+        this.lastName = lastName;
+        this.birthdate = birthdate;
+        this.country = country;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public LocalDate getBirthdate() {
+        return birthdate;
+    }
+
+    public void setBirthdate(LocalDate birthdate) {
+        this.birthdate = birthdate;
+    }
+
+    public String getCountry() {
+        return country;
+    }
+
+    public void setCountry(String country) {
+        this.country = country;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Author author = (Author) o;
+        return Objects.equals(name, author.name) &&
+                Objects.equals(lastName, author.lastName);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, lastName);
+    }
+
+    @Override
+    public String toString() {
+        return "Author{" +
+                "name='" + name + '\'' +
+                ", lastName='" + lastName + '\'' +
+                ", birthdate=" + birthdate +
+                ", country='" + country + '\'' +
+                '}';
+    }
 }

src/main/java/com/epam/izh/rd/online/entity/Book.java

@@ -17,4 +17,56 @@
  */
 public abstract class Book {
 
+    private int numberOfPages;
+    private String name;
+
+    public Book() {
+    }
+
+    public Book(int numberOfPages, String name) {
+        this.numberOfPages = numberOfPages;
+        this.name = name;
+    }
+
+    public int getNumberOfPages() {
+        return numberOfPages;
+    }
+
+    public void setNumberOfPages(int numberOfPages) {
+        this.numberOfPages = numberOfPages;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Book book = (Book) o;
+
+        if (numberOfPages != book.numberOfPages) return false;
+        return Objects.equals(name, book.name);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = numberOfPages;
+        result = 31 * result + (name != null ? name.hashCode() : 0);
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "Book{" +
+                "numberOfPages=" + numberOfPages +
+                ", name='" + name + '\'' +
+                '}';
+    }
 }

src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java

@@ -21,4 +21,66 @@
  */
 public class SchoolBook extends Book {
 
+    private String authorName;
+    private String authorLastName;
+    private LocalDate publishDate;
+
+    public SchoolBook() {
+    }
+
+    public SchoolBook(int numberOfPages, String name, String authorName, String authorLastName, LocalDate publishDate) {
+        super(numberOfPages, name);
+        this.authorName = authorName;
+        this.authorLastName = authorLastName;
+        this.publishDate = publishDate;
+    }
+
+    public String getAuthorName() {
+        return authorName;
+    }
+
+    public void setAuthorName(String authorName) {
+        this.authorName = authorName;
+    }
+
+    public String getAuthorLastName() {
+        return authorLastName;
+    }
+
+    public void setAuthorLastName(String authorLastName) {
+        this.authorLastName = authorLastName;
+    }
+
+    public LocalDate getPublishDate() {
+        return publishDate;
+    }
+
+    public void setPublishDate(LocalDate publishDate) {
+        this.publishDate = publishDate;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        if (!super.equals(o)) return false;
+        SchoolBook that = (SchoolBook) o;
+        return Objects.equals(authorName, that.authorName) &&
+                Objects.equals(authorLastName, that.authorLastName) &&
+                Objects.equals(publishDate, that.publishDate);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), authorName, authorLastName, publishDate);
+    }
+
+    @Override
+    public String toString() {
+        return "SchoolBook{" +
+                "authorName='" + authorName + '\'' +
+                ", authorLastName='" + authorLastName + '\'' +
+                ", publishDate=" + publishDate +
+                '}';
+    }
 }

src/main/java/com/epam/izh/rd/online/repository/SimpleAuthorRepository.java

@@ -0,0 +1,65 @@
+package com.epam.izh.rd.online.repository;
+
+import com.epam.izh.rd.online.entity.Author;
+import org.apache.commons.lang3.ArrayUtils;
+
+import java.util.Arrays;
+
+public class SimpleAuthorRepository implements AuthorRepository {
+
+    private Author[] authors = new Author[0];
+
+    @Override
+    public boolean save(Author author) {
+        if (findByFullName(author.getName(), author.getLastName()) != null) {
+            return false;
+        } else {
+            if (authors == null) {
+                authors = new Author[1];
+                authors[0] = author;
+            } else {
+                Author[] arrayCopy = Arrays.copyOf(authors, authors.length + 1);
+                arrayCopy[arrayCopy.length - 1] = author;
+                authors = arrayCopy;
+            }
+            return true;
+        }
+
+    }
+
+    @Override
+    public Author findByFullName(String name, String lastname) {
+        for (Author author : authors) {
+            if (author.getName().equals(name) && author.getLastName().equals(lastname)) {
+                return author;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public boolean remove(Author author) {
+        if (findByFullName(author.getName(), author.getLastName()) == null) {
+            return false;
+        } else {
+            if (authors.length == 1) {
+                authors = new Author[0];
+                return true;
+            }
+            for (int i = 0; i < authors.length - 1; i++) {
+                if (findByFullName(author.getName(), author.getLastName()).equals(authors[i])) {
+                    Author[] arrayCopy = new Author[authors.length - 1];
+                    System.arraycopy(authors, 0, arrayCopy, 0, i);
+                    System.arraycopy(authors, i + 1, arrayCopy, i, authors.length - i - 1);
+                    authors = arrayCopy;
+                }
+            }
+            return true;
+        }
+    }
+
+    @Override
+    public int count() {
+        return authors.length;
+    }
+}

src/main/java/com/epam/izh/rd/online/repository/SimpleSchoolBookRepository.java

@@ -0,0 +1,65 @@
+package com.epam.izh.rd.online.repository;
+
+import com.epam.izh.rd.online.entity.SchoolBook;
+
+import java.util.Arrays;
+
+public class SimpleSchoolBookRepository implements BookRepository<SchoolBook>{
+
+    private SchoolBook[] schoolBooks = new SchoolBook[0];
+
+    @Override
+    public boolean save(SchoolBook book) {
+        if (schoolBooks == null) {
+            schoolBooks = new SchoolBook[1];
+            schoolBooks[0] = book;
+        } else {
+            SchoolBook[] arrayCopy = Arrays.copyOf(schoolBooks, schoolBooks.length + 1);
+            arrayCopy[arrayCopy.length - 1] = book;
+            schoolBooks = arrayCopy;
+        }
+        return true;
+    }
+
+    @Override
+    public SchoolBook[] findByName(String name) {
+        SchoolBook[] books = new SchoolBook[0];
+        for (SchoolBook book : schoolBooks) {
+            if (book.getName().equals(name)) {
+                SchoolBook[] arrayCopy = Arrays.copyOf(books, books.length + 1);
+                arrayCopy[arrayCopy.length - 1] = book;
+                books = arrayCopy;
+            }
+        }
+        return books;
+    }
+
+    @Override
+    public boolean removeByName(String name) {
+        if (findByName(name).length == 0) {
+            return false;
+        } else {
+            SchoolBook[] newArr = new SchoolBook[schoolBooks.length - findByName(name).length];
+            if (newArr.length == 0) {
+                schoolBooks = new SchoolBook[0];
+                return true;
+            }
+            int n = 0;
+            for (int i = 0; i < schoolBooks.length; i++) {
+                if (schoolBooks[i].getName().equals(findByName(name)[0])) {
+                    n++;
+                    continue;
+                } else {
+                    newArr[i - n] = schoolBooks[i];
+                }
+            }
+            schoolBooks = newArr;
+        }
+        return true;
+    }
+
+    @Override
+    public int count() {
+        return schoolBooks.length;
+    }
+}

src/main/java/com/epam/izh/rd/online/service/SimpleAuthorService.java

@@ -0,0 +1,37 @@
+package com.epam.izh.rd.online.service;
+
+import com.epam.izh.rd.online.entity.Author;
+import com.epam.izh.rd.online.repository.AuthorRepository;
+import com.epam.izh.rd.online.repository.SimpleAuthorRepository;
+
+public class SimpleAuthorService implements AuthorService {
+
+    private AuthorRepository authorRepository;
+
+    public SimpleAuthorService() {
+    }
+
+    public SimpleAuthorService(AuthorRepository authorRepository) {
+        this.authorRepository = authorRepository;
+    }
+
+    @Override
+    public boolean save(Author author) {
+        return authorRepository.save(author);
+    }
+
+    @Override
+    public Author findByFullName(String name, String lastname) {
+        return authorRepository.findByFullName(name, lastname);
+    }
+
+    @Override
+    public boolean remove(Author author) {
+        return authorRepository.remove(author);
+    }
+
+    @Override
+    public int count() {
+        return authorRepository.count();
+    }
+}