Merge pull request #323 from KW-ClassLog/Feat/#322/convert-lecture-to-pdf

✨ Feat/#322 강의자료 pptx pdf로 변환, 녹음본 강의 제목으로 저장

Author: mumminn

backend/Dockerfile

@@ -1,4 +1,9 @@
-FROM openjdk:17-jdk
+FROM eclipse-temurin:17-jdk
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends libreoffice \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
 
 COPY build/libs/backend-0.0.1-SNAPSHOT.jar /app.jar
 

backend/src/main/java/org/example/backend/domain/lecture/entity/Lecture.java

@@ -40,8 +40,10 @@ public class Lecture extends BaseEntity {
     @Column(name = "audio_url")
     private String audioUrl;
 
+    @Column(name = "is_lecture_start")
     private Boolean isLectureStart;
 
+    @Column(name = "save_audio")
     private Boolean saveAudio;
 
     @Column(name = "lecture_date", nullable = false)

backend/src/main/java/org/example/backend/domain/lecture/service/LectureServiceImpl.java

@@ -152,25 +152,28 @@ public void deleteLecture(UUID lectureId) {
 
     //녹음본 저장
     public LectureRecordingResponseDTO uploadLectureRecording(UUID lectureId, MultipartFile file) {
+
         Lecture lecture = lectureRepository.findById(lectureId)
                 .orElseThrow(() -> new LectureException(LectureErrorCode.LECTURE_NOT_FOUND));
 
-        String key = "recordings/" + lectureId +"/" + UUID.randomUUID() + "/" + file.getOriginalFilename();
+        String safeLectureName = lecture.getLectureName().replaceAll("\\s+", "_");
+        String uploadFileName = safeLectureName + ".mp3";
+
+        String key = "recordings/" + lectureId + "/" + UUID.randomUUID() + "/" + uploadFileName;
 
         try {
-            s3Service.uploadFile(file, key); // private 업로드
+            s3Service.uploadFile(file, key);
         } catch (IOException e) {
             throw new S3Exception(S3ErrorCode.UPLOAD_FAIL);
         }
 
         lecture.setAudioUrl(key);
         lectureRepository.save(lecture);
-
-        String audioName = key.substring(key.lastIndexOf('/') + 1);
+        lecture.setSaveAudio(true);
 
         return LectureRecordingResponseDTO.builder()
                 .lectureId(lecture.getId())
-                .audioName(audioName)
+                .audioName(uploadFileName)
                 .audioUrl(s3Service.getPresignedUrl(key))
                 .build();
     }

backend/src/main/java/org/example/backend/domain/lectureNote/converter/FileToMultipartFileConverter.java

@@ -0,0 +1,58 @@
+package org.example.backend.domain.lectureNote.converter;
+
+import org.springframework.web.multipart.MultipartFile;
+import java.io.*;
+
+public class FileToMultipartFileConverter implements MultipartFile {
+
+    private final File file;
+    private final String contentType;
+
+    // file -> multipartFile 변환
+    public FileToMultipartFileConverter(File file, String contentType) {
+        this.file = file;
+        this.contentType = contentType;
+    }
+
+    @Override
+    public String getName() {
+        return file.getName();
+    }
+
+    @Override
+    public String getOriginalFilename() {
+        return file.getName();
+    }
+
+    @Override
+    public String getContentType() {
+        return contentType;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return file.length() == 0;
+    }
+
+    @Override
+    public long getSize() {
+        return file.length();
+    }
+
+    @Override
+    public byte[] getBytes() throws IOException {
+        return java.nio.file.Files.readAllBytes(file.toPath());
+    }
+
+    @Override
+    public InputStream getInputStream() throws IOException {
+        return new FileInputStream(file);
+    }
+
+    @Override
+    public void transferTo(File dest) throws IOException {
+        try (InputStream in = getInputStream(); OutputStream out = new FileOutputStream(dest)) {
+            in.transferTo(out);
+        }
+    }
+}

backend/src/main/java/org/example/backend/domain/lectureNote/converter/LibreOfficeConverter.java

@@ -0,0 +1,40 @@
+package org.example.backend.domain.lectureNote.converter;
+import org.springframework.stereotype.Component;
+
+import java.io.File;
+import java.io.IOException;
+
+@Component
+public class LibreOfficeConverter {
+
+    // pptx -> pdf 변환
+    public File convertPptxToPdf(File pptxFile) throws IOException {
+        try {
+            String outputDir = pptxFile.getParent();
+
+            String baseName = pptxFile.getName().replaceAll("(?i)\\.pptx$", "");
+            File outputPdf = new File(outputDir, baseName + ".pdf");
+
+            ProcessBuilder pb = new ProcessBuilder(
+                    "libreoffice", "--headless",
+                    "--convert-to", "pdf:writer_pdf_Export",
+                    pptxFile.getAbsolutePath(),
+                    "--outdir", outputDir
+            );
+            Process process = pb.start();
+            int exitCode = process.waitFor();
+            if (exitCode != 0) {
+                throw new IOException("LibreOffice 변환 실패: exitCode=" + exitCode);
+            }
+
+            if (!outputPdf.exists()) {
+                throw new IOException("LibreOffice 변환 실패: 출력 PDF 없음");
+            }
+
+            return outputPdf;
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IOException("LibreOffice 변환 중 인터럽트 발생", e);
+        }
+    }
+}

backend/src/main/java/org/example/backend/domain/lectureNote/service/LectureNoteServiceImpl.java

@@ -5,6 +5,8 @@
 import org.example.backend.domain.classroom.exception.ClassroomErrorCode;
 import org.example.backend.domain.classroom.exception.ClassroomException;
 import org.example.backend.domain.classroom.repository.ClassroomRepository;
+import org.example.backend.domain.lectureNote.converter.FileToMultipartFileConverter;
+import org.example.backend.domain.lectureNote.converter.LibreOfficeConverter;
 import org.example.backend.domain.lectureNote.dto.response.LectureNoteKeyResponseDTO;
 import org.example.backend.domain.lectureNote.dto.response.LectureNoteResponseDTO;
 import org.example.backend.domain.lectureNote.entity.LectureNote;
@@ -17,6 +19,7 @@
 import org.springframework.stereotype.Service;
 import org.springframework.web.multipart.MultipartFile;
 
+import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -29,31 +32,67 @@ public class LectureNoteServiceImpl implements LectureNoteService {
 
     private final S3Service s3Service;
     private final LectureNoteRepository lectureNoteRepository;
-    private final ClassroomRepository classroomRepository; // ✅ 추가
+    private final ClassroomRepository classroomRepository;
     private final LectureNoteMappingRepository lectureNoteMappingRepository;
+    private final LibreOfficeConverter libreOfficeConverter;
 
     public List<LectureNote> uploadLectureNotes(UUID classId, List<MultipartFile> files) throws IOException {
-        // 1. 여러 파일에 대해 처리
         List<LectureNote> lectureNotes = new ArrayList<>();
 
-        // 2. 각 파일 업로드 처리
         for (MultipartFile file : files) {
-            // 1) S3에 업로드
-            String key = "lecture_note/" + classId + "/" + UUID.randomUUID() + "/" + file.getOriginalFilename();
-            String fileUrl = s3Service.uploadFile(file, key);
-
-            // 2) classId로 Classroom 엔티티 조회
-            Classroom classroom = classroomRepository.findById(classId)
-                    .orElseThrow(() -> new ClassroomException(ClassroomErrorCode.CLASS_NOT_FOUND));
-
-            // 3) LectureNote 객체 생성
-            LectureNote lectureNote = LectureNote.builder()
-                    .noteUrl(key)
-                    .classroom(classroom) // Classroom 객체 넣기
-                    .build();
-
-            // 4) LectureNote 저장
-            lectureNotes.add(lectureNoteRepository.save(lectureNote));
+            String originalFilename = Objects.requireNonNull(file.getOriginalFilename(), "파일명이 필요합니다");
+            boolean isPptx = originalFilename.toLowerCase().endsWith(".pptx");
+
+            File tempSrc = null;
+            File convertedPdf = null;
+            String uploadFileName;
+            String key;
+            MultipartFile pdfMultipart;
+
+            try {
+                if (isPptx) {
+                    // MultipartFile -> File
+                    tempSrc = new File(System.getProperty("java.io.tmpdir"), originalFilename);
+                    file.transferTo(tempSrc);
+
+                    try {
+                        // PPTX → PDF 변환
+                        convertedPdf = libreOfficeConverter.convertPptxToPdf(tempSrc);
+
+                        // File -> MultipartFile
+                        pdfMultipart = new FileToMultipartFileConverter(convertedPdf, "application/pdf");
+                    } catch (Exception e) {
+                        throw new IOException("PPTX→PDF 변환 실패: " + originalFilename, e);
+                    }
+
+                    uploadFileName = convertedPdf.getName();
+
+                    // S3 업로드
+                    key = "lecture_note/" + classId + "/" + UUID.randomUUID() + "/" + uploadFileName;
+                    s3Service.uploadFile(pdfMultipart, key);
+
+                } else {
+                    // pptx 외 다른 파일들 그대로 업로드
+                    uploadFileName = originalFilename;
+                    key = "lecture_note/" + classId + "/" + UUID.randomUUID() + "/" + uploadFileName;
+                    s3Service.uploadFile(file, key);
+                }
+
+                Classroom classroom = classroomRepository.findById(classId)
+                        .orElseThrow(() -> new ClassroomException(ClassroomErrorCode.CLASS_NOT_FOUND));
+
+                LectureNote lectureNote = LectureNote.builder()
+                        .noteUrl(key)
+                        .classroom(classroom)
+                        .build();
+
+                lectureNotes.add(lectureNoteRepository.save(lectureNote));
+
+            } finally {
+                // pdf로 변환하며 생긴 임시 파일 삭제
+                if (tempSrc != null && tempSrc.exists()) tempSrc.delete();
+                if (convertedPdf != null && convertedPdf.exists()) convertedPdf.delete();
+            }
         }
 
         return lectureNotes;