lab-3 adding book and users pagination

SpringApp/library/src/main/java/com/ip/library/books/api/BookController.java

@@ -51,8 +51,10 @@ public class BookController {
     @GetMapping
     public List<BookDto> getAll(
                 @RequestParam(name = "typeId", defaultValue = "0") Long typeId,
-        @RequestParam(name = "authorId", defaultValue = "0") Long authorId) {
+                @RequestParam(name = "authorId", defaultValue = "0") Long authorId,
-        return itemService.getAllbyFilter(typeId, authorId).stream().map(this::toDto).toList();
+                @RequestParam(name = "page", defaultValue = "0") int page,
+                @RequestParam(name = "size", defaultValue = Constants.DEFAULT_PAGE_SIZE) int size) {
+        return itemService.getAll(typeId, authorId).stream().map(this::toDto).toList();
     }
 
     @GetMapping("/{id}")

SpringApp/library/src/main/java/com/ip/library/books/repository/BookRepository.java

@@ -3,13 +3,20 @@ package com.ip.library.books.repository;
 import java.util.List;
 import java.util.Optional;
 
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.PagingAndSortingRepository;
 
 import com.ip.library.books.model.BookEntity;
 
-public interface BookRepository extends CrudRepository<BookEntity, Long> {
+public interface BookRepository extends 
+		CrudRepository<BookEntity, Long>, 
+		PagingAndSortingRepository<BookEntity, Long> {
 	Optional<BookEntity> findByNameIgnoreCase(String name);
 	List<BookEntity> findByTypeId(long typeId);
+	List<BookEntity> findByTypeId(long typeId, Pageable pageable);
 	List<BookEntity> findByAuthorId(long authorId);
+	List<BookEntity> findByAuthorId(long authorId, Pageable pageable);
 	List<BookEntity> findByTypeIdAndAuthorId(long typeId, long authorId);
+	List<BookEntity> findByTypeIdAndAuthorId(long typeId, long authorId, Pageable pageable);
 }

SpringApp/library/src/main/java/com/ip/library/books/service/BookService.java

@@ -3,6 +3,7 @@ package com.ip.library.books.service;
 import java.util.List;
 import java.util.stream.StreamSupport;
 
+import org.springframework.data.domain.PageRequest;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -32,7 +33,7 @@ public class BookService {
     }
 
     @Transactional(readOnly = true)
-    public List<BookEntity> getAllbyFilter(long typeId, long authorId) {
+    public List<BookEntity> getAll(long typeId, long authorId) {
         if (typeId <= 0L && authorId <= 0L) {
             return getAll();
         }
@@ -45,6 +46,21 @@ public class BookService {
         return repository.findByTypeIdAndAuthorId(typeId, authorId);
     }
 
+    @Transactional(readOnly = true)
+    public List<BookEntity> getAll(long typeId, long authorId, int page, int size) {
+        PageRequest pageRequest = PageRequest.of(page, size);
+        if (typeId <= 0L && authorId <= 0L) {
+            return StreamSupport.stream(repository.findAll(pageRequest).spliterator(), false).toList();
+        }
+        if (typeId <= 0L){
+            return repository.findByAuthorId(authorId, pageRequest);
+        }
+        if (authorId <= 0L){
+            return repository.findByTypeId(typeId, pageRequest);
+        }
+        return repository.findByTypeIdAndAuthorId(typeId, authorId, pageRequest);
+    }
+
     @Transactional(readOnly = true)
     public BookEntity get(long id) {
         return repository.findById(id)

SpringApp/library/src/main/java/com/ip/library/core/api/PageDto.java

@@ -0,0 +1,97 @@
+package com.ip.library.core.api;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PageDto<D> {
+    private List<D> items = new ArrayList<>();
+    private int itemsCount;
+    private int currentPage;
+    private int currentSize;
+    private int totalPages;
+    private long totalItems;
+    private boolean isFirst;
+    private boolean isLast;
+    private boolean hasNext;
+    private boolean hasPrevious;
+
+    public List<D> getItems() {
+        return items;
+    }
+
+    public void setItems(List<D> items) {
+        this.items = items;
+    }
+
+    public int getItemsCount() {
+        return itemsCount;
+    }
+
+    public void setItemsCount(int itemsCount) {
+        this.itemsCount = itemsCount;
+    }
+
+    public int getCurrentPage() {
+        return currentPage;
+    }
+
+    public void setCurrentPage(int currentPage) {
+        this.currentPage = currentPage;
+    }
+
+    public int getCurrentSize() {
+        return currentSize;
+    }
+
+    public void setCurrentSize(int currentSize) {
+        this.currentSize = currentSize;
+    }
+
+    public int getTotalPages() {
+        return totalPages;
+    }
+
+    public void setTotalPages(int totalPages) {
+        this.totalPages = totalPages;
+    }
+
+    public long getTotalItems() {
+        return totalItems;
+    }
+
+    public void setTotalItems(long totalItems) {
+        this.totalItems = totalItems;
+    }
+
+    public boolean isFirst() {
+        return isFirst;
+    }
+
+    public void setFirst(boolean isFirst) {
+        this.isFirst = isFirst;
+    }
+
+    public boolean isLast() {
+        return isLast;
+    }
+
+    public void setLast(boolean isLast) {
+        this.isLast = isLast;
+    }
+
+    public boolean isHasNext() {
+        return hasNext;
+    }
+
+    public void setHasNext(boolean hasNext) {
+        this.hasNext = hasNext;
+    }
+
+    public boolean isHasPrevious() {
+        return hasPrevious;
+    }
+
+    public void setHasPrevious(boolean hasPrevious) {
+        this.hasPrevious = hasPrevious;
+    }
+}

SpringApp/library/src/main/java/com/ip/library/core/api/PageDtoMapper.java

@@ -0,0 +1,24 @@
+package com.ip.library.core.api;
+
+import java.util.function.Function;
+
+import org.springframework.data.domain.Page;
+
+public class PageDtoMapper {
+    private PageDtoMapper() {}
+
+    public static <D, E> PageDto<D> toDto(Page<E> page, Function<E, D> mapper) {
+        final PageDto<D> dto = new PageDto<>();
+        dto.setItems(page.getContent().stream().map(mapper::apply).toList());
+        dto.setItemsCount(page.getNumberOfElements());
+        dto.setCurrentPage(page.getNumber());
+        dto.setCurrentSize(page.getSize());
+        dto.setTotalPages(page.getTotalPages());
+        dto.setTotalItems(page.getTotalElements());
+        dto.setFirst(page.isFirst());
+        dto.setLast(page.isLast());
+        dto.setHasNext(page.hasNext());
+        dto.setHasPrevious(page.hasPrevious());
+        return dto;
+    }
+}

SpringApp/library/src/main/java/com/ip/library/core/configuration/Constants.java

@@ -5,6 +5,7 @@ public class Constants {
 
     public static final String API_URL = "/api/1.0";
 
-    private Constants() {
+    public static final String DEFAULT_PAGE_SIZE = "5";
-    }
+
+    private Constants() {}
 }

SpringApp/library/src/main/java/com/ip/library/users/api/UserController.java

@@ -1,7 +1,5 @@
 package com.ip.library.users.api;
 
-import java.util.List;
-
 import org.modelmapper.ModelMapper;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -10,8 +8,11 @@ import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import com.ip.library.core.api.PageDto;
+import com.ip.library.core.api.PageDtoMapper;
 import com.ip.library.core.configuration.Constants;
 import com.ip.library.users.model.UserEntity;
 import com.ip.library.users.service.UserService;
@@ -38,8 +39,10 @@ public class UserController {
     }
 
     @GetMapping
-    public List<UserDto> getAll() {
+    public PageDto<UserDto> getAll(
-        return userService.getAll().stream().map(this::toDto).toList();
+                @RequestParam(name = "page", defaultValue = "0") int page,
+                @RequestParam(name = "size", defaultValue = Constants.DEFAULT_PAGE_SIZE) int size) {
+        return PageDtoMapper.toDto(userService.getAll(page, size), this::toDto);
     }
 
     @GetMapping("/{id}")

SpringApp/library/src/main/java/com/ip/library/users/repository/UserRepository.java

@@ -3,9 +3,12 @@ package com.ip.library.users.repository;
 import java.util.Optional;
 
 import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.PagingAndSortingRepository;
 
 import com.ip.library.users.model.UserEntity;
 
-public interface UserRepository extends CrudRepository<UserEntity, Long> {
+public interface UserRepository extends 
+			CrudRepository<UserEntity, Long>, 
+			PagingAndSortingRepository<UserEntity, Long> {
 	Optional<UserEntity> findByLoginIgnoreCase(String login);
 }

SpringApp/library/src/main/java/com/ip/library/users/service/UserService.java

@@ -3,6 +3,8 @@ package com.ip.library.users.service;
 import java.util.List;
 import java.util.stream.StreamSupport;
 
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -31,6 +33,11 @@ public class UserService {
         return StreamSupport.stream(repository.findAll().spliterator(), false).toList();
     }
 
+    @Transactional(readOnly = true)
+    public Page<UserEntity> getAll(int page, int size) {
+        return repository.findAll(PageRequest.of(page, size));
+    }
+
     @Transactional(readOnly = true)
     public UserEntity get(long id) {
         return repository.findById(id)