完成了Course的相关支持

src/main/java/org/cmh/backend/CourseManagement/model/Course.java

@@ -2,21 +2,21 @@ package org.cmh.backend.CourseManagement.model;
 
 import jakarta.persistence.*;
 import lombok.Data;
-
+import lombok.Getter;
+import lombok.Setter;
 @Data
 @Entity
-@Table(name = "courses")
+@Getter
+@Setter
 public class Course {
-
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
-    private String name;
-    private String description;
-    private String author;
-    private String sortOrder;
-    private String coverImagePath;
-    private String videoPath;
 
-    // getters and setters
+    private String title;
+    private String description;
+    private String order;
+    private String author;
+    private String videoPath;
+    private String imagePath;
 }

src/main/java/org/cmh/backend/CourseManagement/repository/CourseRepository.java

@@ -1,9 +1,10 @@
 package org.cmh.backend.CourseManagement.repository;
 
 import org.cmh.backend.CourseManagement.model.Course;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
-import java.util.Optional;
 
 public interface CourseRepository extends JpaRepository<Course, Long> {
-    Optional<Course> findByName(String name);
+    Page<Course> findAllByOrderByIdDesc(Pageable pageable);
 }

src/main/java/org/cmh/backend/CourseManagement/service/CourseService.java

@@ -1,96 +1,190 @@
+//package org.cmh.backend.CourseManagement.service;
+//
+//import org.cmh.backend.CourseManagement.model.Course;
+//import org.cmh.backend.CourseManagement.repository.CourseRepository;
+//import org.springframework.beans.factory.annotation.Autowired;
+//import org.springframework.stereotype.Service;
+//import org.springframework.web.multipart.MultipartFile;
+//
+//import java.io.IOException;
+//import java.nio.file.Files;
+//import java.nio.file.Path;
+//import java.nio.file.Paths;
+//import java.util.List;
+//import java.util.Optional;
+//
+//@Service
+//public class CourseService {
+//
+//    @Autowired
+//    private CourseRepository courseRepository;
+//
+//    public Course createCourse(String name, String description, String author, String sortOrder, MultipartFile coverImage, MultipartFile video) {
+//        Optional<Course> existingCourse = courseRepository.findByName(name);
+//        if (existingCourse.isPresent()) {
+//            return null;
+//        }
+//
+//        Course course = new Course();
+//        course.setName(name);
+//        course.setDescription(description);
+//        course.setAuthor(author);
+//        course.setSortOrder(sortOrder);
+//
+//        try {
+//            if (coverImage != null && !coverImage.isEmpty()) {
+//                String coverImagePath = saveFile(coverImage);
+//                course.setCoverImagePath(coverImagePath);
+//            }
+//            if (video != null && !video.isEmpty()) {
+//                String videoPath = saveFile(video);
+//                course.setVideoPath(videoPath);
+//            }
+//        } catch (IOException e) {
+//            e.printStackTrace();
+//            return null;
+//        }
+//
+//        return courseRepository.save(course);
+//    }
+//
+//    public Course updateCourse(Long id, String name, String description, String author, String sortOrder, MultipartFile coverImage, MultipartFile video) {
+//        return courseRepository.findById(id)
+//                .map(course -> {
+//                    course.setName(name);
+//                    course.setDescription(description);
+//                    course.setAuthor(author);
+//                    course.setSortOrder(sortOrder);
+//
+//                    try {
+//                        if (coverImage != null && !coverImage.isEmpty()) {
+//                            String coverImagePath = saveFile(coverImage);
+//                            course.setCoverImagePath(coverImagePath);
+//                        }
+//                        if (video != null && !video.isEmpty()) {
+//                            String videoPath = saveFile(video);
+//                            course.setVideoPath(videoPath);
+//                        }
+//                    } catch (IOException e) {
+//                        e.printStackTrace();
+//                        return null;
+//                    }
+//
+//                    return courseRepository.save(course);
+//                }).orElse(null);
+//    }
+//
+//    private String saveFile(MultipartFile file) throws IOException {
+//        String filename = System.currentTimeMillis() + "_" + file.getOriginalFilename();
+//        Path filePath = Paths.get("uploads", filename);
+//        Files.createDirectories(filePath.getParent());
+//        Files.write(filePath, file.getBytes());
+//        return filePath.toString();
+//    }
+//
+//    public boolean deleteCourse(Long id) {
+//        return courseRepository.findById(id)
+//                .map(course -> {
+//                    courseRepository.delete(course);
+//                    return true;
+//                }).orElse(false);
+//    }
+//
+//    public List<Course> getAllCourses() {
+//        return courseRepository.findAll();
+//    }
+//}
 package org.cmh.backend.CourseManagement.service;
 
+import jakarta.persistence.EntityNotFoundException;
+import org.cmh.backend.CourseManagement.dto.CourseRequest;
 import org.cmh.backend.CourseManagement.model.Course;
 import org.cmh.backend.CourseManagement.repository.CourseRepository;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
-import org.springframework.web.multipart.MultipartFile;
 
-import java.io.IOException;
+import java.util.ArrayList;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.List;
-import java.util.Optional;
 
 @Service
 public class CourseService {
-
     @Autowired
     private CourseRepository courseRepository;
 
-    public Course createCourse(String name, String description, String author, String sortOrder, MultipartFile coverImage, MultipartFile video) {
+    public List<Course> getCoursesByRange(int start, int end) {
-        Optional<Course> existingCourse = courseRepository.findByName(name);
+        if (start < 0 || end <= start) {
-        if (existingCourse.isPresent()) {
+            throw new IllegalArgumentException("Invalid start or end range");
-            return null;
         }
 
+        int pageSize = end - start; // 计算每页的大小
+        int startPageNumber = start / pageSize; // 计算起始页码
+        int endPageNumber = (end - 1) / pageSize; // 计算结束页码
+
+        List<Course> result = new ArrayList<>();
+
+        for (int pageNumber = startPageNumber; pageNumber <= endPageNumber; pageNumber++) {
+            Pageable pageable = PageRequest.of(pageNumber, pageSize);
+            Page<Course> coursePage = courseRepository.findAllByOrderByIdDesc(pageable);
+
+            if (coursePage.hasContent()) {
+                result.addAll(coursePage.getContent());
+            } else {
+                break; // 如果没有更多内容，提前退出
+            }
+        }
+
+        int startIndex = start % pageSize;
+        int endIndex = startIndex + (end - start);
+
+        if (endIndex > result.size()) {
+            endIndex = result.size();
+        }
+
+        return result.subList(startIndex, endIndex);
+    }
+
+    public void createCourse(CourseRequest request) {
         Course course = new Course();
-        course.setName(name);
+        course.setTitle(request.getTitle());
-        course.setDescription(description);
+        course.setDescription(request.getDescription());
-        course.setAuthor(author);
+        course.setOrder(request.getOrder());
-        course.setSortOrder(sortOrder);
+        course.setAuthor(request.getAuthor());
-
+        course.setVideoPath(request.getVideoPath());
-        try {
+        course.setImagePath(request.getImagePath());
-            if (coverImage != null && !coverImage.isEmpty()) {
+        courseRepository.save(course);
-                String coverImagePath = saveFile(coverImage);
-                course.setCoverImagePath(coverImagePath);
-            }
-            if (video != null && !video.isEmpty()) {
-                String videoPath = saveFile(video);
-                course.setVideoPath(videoPath);
-            }
-        } catch (IOException e) {
-            e.printStackTrace();
-            return null;
     }
 
-        return courseRepository.save(course);
+    public void updateCourse(Long id, CourseRequest request) {
+        Course course = courseRepository.findById(id).orElse(null);
+        if (course != null) {
+            course.setTitle(request.getTitle());
+            course.setDescription(request.getDescription());
+            course.setOrder(request.getOrder());
+            course.setAuthor(request.getAuthor());
+            course.setVideoPath(request.getVideoPath());
+            course.setImagePath(request.getImagePath());
+            courseRepository.save(course);
+        }
     }
 
-    public Course updateCourse(Long id, String name, String description, String author, String sortOrder, MultipartFile coverImage, MultipartFile video) {
+    public void deleteCourse(Long id) {
-        return courseRepository.findById(id)
+        if (!courseRepository.existsById(id)) {
-                .map(course -> {
+            throw new EntityNotFoundException();
-                    course.setName(name);
-                    course.setDescription(description);
-                    course.setAuthor(author);
-                    course.setSortOrder(sortOrder);
-
-                    try {
-                        if (coverImage != null && !coverImage.isEmpty()) {
-                            String coverImagePath = saveFile(coverImage);
-                            course.setCoverImagePath(coverImagePath);
         }
-                        if (video != null && !video.isEmpty()) {
+        courseRepository.deleteById(id);
-                            String videoPath = saveFile(video);
-                            course.setVideoPath(videoPath);
-                        }
-                    } catch (IOException e) {
-                        e.printStackTrace();
-                        return null;
     }
 
-                    return courseRepository.save(course);
+    public Course getCourseById(Long id) {
-                }).orElse(null);
+        if (!courseRepository.existsById(id)) {
+            throw new EntityNotFoundException();
+        }
+        return courseRepository.findById(id).orElse(null);
     }
 
-    private String saveFile(MultipartFile file) throws IOException {
+    public long getCourseCount() {
-        String filename = System.currentTimeMillis() + "_" + file.getOriginalFilename();
+        return courseRepository.count();
-        Path filePath = Paths.get("uploads", filename);
-        Files.createDirectories(filePath.getParent());
-        Files.write(filePath, file.getBytes());
-        return filePath.toString();
-    }
-
-    public boolean deleteCourse(Long id) {
-        return courseRepository.findById(id)
-                .map(course -> {
-                    courseRepository.delete(course);
-                    return true;
-                }).orElse(false);
-    }
-
-    public List<Course> getAllCourses() {
-        return courseRepository.findAll();
     }
 }