search were implemented

src/main/java/bookstore/controller/BookController.java

@@ -2,6 +2,7 @@
 
 import bookstore.dto.BookDto;
 import bookstore.dto.BookRequestDto;
+import bookstore.dto.BookSearchParametersDto;
 import bookstore.mapper.BookMapper;
 import bookstore.model.Book;
 import bookstore.service.BookService;
@@ -54,4 +55,14 @@ public BookDto updateBook(@PathVariable Long id, @RequestBody BookRequestDto req
     public void deleteBook(@PathVariable Long id) {
         bookService.deleteById(id);
     }
+
+    @GetMapping("/search")
+    @ResponseStatus(HttpStatus.OK)
+    public List<BookDto> searchBooks(BookSearchParametersDto searchParameters) {
+        return bookService.search(searchParameters)
+                .stream()
+                .map(bookMapper::toDto)
+                .toList();
+    }
+
 }

src/main/java/bookstore/dto/BookSearchParametersDto.java

@@ -0,0 +1,4 @@
+package bookstore.dto;
+
+public record BookSearchParametersDto(String[] authors, String[] titles) {
+}

src/main/java/bookstore/repository/SpecificationBuilder.java

@@ -0,0 +1,8 @@
+package bookstore.repository;
+
+import bookstore.dto.BookSearchParametersDto;
+import org.springframework.data.jpa.domain.Specification;
+
+public interface SpecificationBuilder<T> {
+    Specification<T> build(BookSearchParametersDto searchParameters);
+}

src/main/java/bookstore/repository/SpecificationProvider.java

@@ -0,0 +1,9 @@
+package bookstore.repository;
+
+import org.springframework.data.jpa.domain.Specification;
+
+public interface SpecificationProvider<T> {
+    String getKey();
+
+    Specification<T> getSpecification(String[] params);
+}

src/main/java/bookstore/repository/SpecificationProviderManager.java

@@ -0,0 +1,5 @@
+package bookstore.repository;
+
+public interface SpecificationProviderManager<T> {
+    SpecificationProvider<T> getSpecificationProvider(String key);
+}

src/main/java/bookstore/repository/BookRepository.java → src/main/java/bookstore/repository/book/BookRepository.java

@@ -1,9 +1,10 @@
-package bookstore.repository;
+package bookstore.repository.book;
 
 import bookstore.model.Book;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
 import org.springframework.stereotype.Repository;
 
 @Repository
-public interface BookRepository extends JpaRepository<Book, Long> {
+public interface BookRepository extends JpaRepository<Book, Long>, JpaSpecificationExecutor<Book> {
 }

src/main/java/bookstore/repository/book/BookSpecificationBuilder.java

@@ -0,0 +1,29 @@
+package bookstore.repository.book;
+
+import bookstore.dto.BookSearchParametersDto;
+import bookstore.model.Book;
+import bookstore.repository.SpecificationBuilder;
+import bookstore.repository.SpecificationProviderManager;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.jpa.domain.Specification;
+import org.springframework.stereotype.Component;
+
+@RequiredArgsConstructor
+@Component
+public class BookSpecificationBuilder implements SpecificationBuilder<Book> {
+    private final SpecificationProviderManager<Book> bookSpecificationProviderManager;
+
+    @Override
+    public Specification<Book> build(BookSearchParametersDto searchParameters) {
+        Specification<Book> spec = Specification.where(null);
+        if (searchParameters.titles() != null && searchParameters.titles().length > 0) {
+            spec = spec.and(bookSpecificationProviderManager.getSpecificationProvider("title")
+                    .getSpecification(searchParameters.titles()));
+        }
+        if (searchParameters.authors() != null && searchParameters.authors().length > 0) {
+            spec = spec.and(bookSpecificationProviderManager.getSpecificationProvider("author")
+                    .getSpecification(searchParameters.authors()));
+        }
+        return spec;
+    }
+}

src/main/java/bookstore/repository/book/BookSpecificationProviderManager.java

@@ -0,0 +1,24 @@
+package bookstore.repository.book;
+
+import bookstore.model.Book;
+import bookstore.repository.SpecificationProvider;
+import bookstore.repository.SpecificationProviderManager;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+@RequiredArgsConstructor
+@Component
+public class BookSpecificationProviderManager implements SpecificationProviderManager<Book> {
+    private final List<SpecificationProvider<Book>> bookSpecificationProviders;
+
+    @Override
+    public SpecificationProvider<Book> getSpecificationProvider(String key) {
+        return bookSpecificationProviders.stream()
+                .filter(p -> p.getKey().equals(key))
+                .findFirst()
+                .orElseThrow(() -> new RuntimeException("Cant find correct specification "
+                        + "provider for key" + key));
+    }
+}
+

src/main/java/bookstore/repository/book/spec/AuthorSpecificationProvider.java

@@ -0,0 +1,23 @@
+package bookstore.repository.book.spec;
+
+import bookstore.model.Book;
+import bookstore.repository.SpecificationProvider;
+import java.util.Arrays;
+import org.springframework.data.jpa.domain.Specification;
+import org.springframework.stereotype.Component;
+
+@Component
+public class AuthorSpecificationProvider implements SpecificationProvider<Book> {
+    private static final String KEY_AUTHOR = "author";
+
+    @Override
+    public String getKey() {
+        return KEY_AUTHOR;
+    }
+
+    @Override
+    public Specification<Book> getSpecification(String[] params) {
+        return (root, query, criteriaBuilder)
+                -> root.get(KEY_AUTHOR).in(Arrays.stream(params).toArray());
+    }
+}

src/main/java/bookstore/repository/book/spec/TitleSpecificationProvider.java

@@ -0,0 +1,23 @@
+package bookstore.repository.book.spec;
+
+import bookstore.model.Book;
+import bookstore.repository.SpecificationProvider;
+import java.util.Arrays;
+import org.springframework.data.jpa.domain.Specification;
+import org.springframework.stereotype.Component;
+
+@Component
+public class TitleSpecificationProvider implements SpecificationProvider<Book> {
+    private static final String KEY_TITLE = "title";
+
+    @Override
+    public String getKey() {
+        return KEY_TITLE;
+    }
+
+    public Specification<Book> getSpecification(String[] params) {
+        return (root, query, criteriaBuilder)
+                -> root.get(KEY_TITLE).in(Arrays.stream(params).toArray());
+    }
+
+}

src/main/java/bookstore/service/BookService.java

@@ -1,5 +1,6 @@
 package bookstore.service;
 
+import bookstore.dto.BookSearchParametersDto;
 import bookstore.model.Book;
 import java.util.List;
 
@@ -13,4 +14,6 @@ public interface BookService {
     Book updateById(Long id, Book book);
 
     void deleteById(Long id);
+
+    List<Book> search(BookSearchParametersDto params);
 }

src/main/java/bookstore/service/impl/BookServiceImpl.java

@@ -1,12 +1,15 @@
 package bookstore.service.impl;
 
+import bookstore.dto.BookSearchParametersDto;
 import bookstore.exception.EntityNotFoundException;
 import bookstore.model.Book;
-import bookstore.repository.BookRepository;
+import bookstore.repository.book.BookRepository;
+import bookstore.repository.book.BookSpecificationBuilder;
 import bookstore.service.BookService;
 import jakarta.transaction.Transactional;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
+import org.springframework.data.jpa.domain.Specification;
 import org.springframework.stereotype.Service;
 import org.springframework.web.bind.annotation.RequestBody;
 
@@ -15,6 +18,7 @@
 public class BookServiceImpl implements BookService {
 
     private final BookRepository bookRepository;
+    private final BookSpecificationBuilder bookSpecificationBuilder;
 
     @Override
     public Book save(Book book) {
@@ -45,4 +49,10 @@ public Book updateById(Long id, @RequestBody Book book) {
     public void deleteById(Long id) {
         bookRepository.deleteById(id);
     }
+
+    @Override
+    public List<Book> search(BookSearchParametersDto params) {
+        Specification<Book> bookSpecification = bookSpecificationBuilder.build(params);
+        return bookRepository.findAll(bookSpecification);
+    }
 }