Merge branch 'feat/behavior_record' of FanYanPeng/EAI-Backend into refactor

https://nqq5jc94uf.feishu.cn/wiki/RmqPwlVTyiShASkMQZBcaa7WnSb

src/main/java/com/njuzr/eaibackend/controller/ExportController.java

@@ -112,7 +112,7 @@ public class ExportController {
 
     @GetMapping("/behaviorOverview/excel/assignment")
     public ResponseEntity<byte[]> exportAssignmentBehaviorOverviewExcel(@RequestParam Long assignmentId) {
-        byte[] bytes = exportBehaviorOverviewService.exportAssignmentBehaviorOverviewExcel(assignmentId);
+        byte[] bytes = exportBehaviorOverviewService.exportAssignmentBehaviorOverviewZip(assignmentId);
 
         HttpHeaders headers = new HttpHeaders();
         headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
@@ -123,8 +123,8 @@ public class ExportController {
         } catch (Exception ignored) { }
 
         String fileName = assignmentName == null || assignmentName.isEmpty()
-                ? String.format("行为数据记录_%d.xlsx", assignmentId)
-                : String.format("行为数据记录_%d_%s.xlsx", assignmentId, assignmentName);
+                ? String.format("行为数据记录_%d.zip", assignmentId)
+                : String.format("行为数据记录_%s.zip", assignmentName);
 
         headers.setContentDisposition(ContentDisposition.builder("attachment")
                 .filename(fileName, StandardCharsets.UTF_8)
@@ -164,7 +164,7 @@ public class ExportController {
 
     @GetMapping("/behaviorOverview/excel/class")
     public ResponseEntity<byte[]> exportClassBehaviorOverviewExcel(@RequestParam Long classId) {
-        byte[] bytes = exportBehaviorOverviewService.exportClassBehaviorOverviewExcel(classId);
+        byte[] bytes = exportBehaviorOverviewService.exportClassBehaviorOverviewZip(classId);
 
         HttpHeaders headers = new HttpHeaders();
         headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
@@ -175,8 +175,41 @@ public class ExportController {
         } catch (Exception ignored) { }
 
         String fileName = className == null || className.isEmpty()
-                ? String.format("行为数据记录_%d.xlsx", classId)
-                : String.format("行为数据记录_%d_%s.xlsx", classId, className);
+                ? String.format("行为数据记录_%d.zip", classId)
+                : String.format("行为数据记录_%s.zip", className);
+
+        headers.setContentDisposition(ContentDisposition.builder("attachment")
+                .filename(fileName, StandardCharsets.UTF_8)
+                .build());
+
+        return ResponseEntity.ok()
+                .headers(headers)
+                .body(bytes);
+    }
+
+    @GetMapping("/behaviorOverview/excel/class/assignment")
+    public ResponseEntity<byte[]> exportClassAssignmentBehaviorOverviewExcel(@RequestParam Long classId, @RequestParam Long assignmentId) {
+        byte[] bytes = exportBehaviorOverviewService.exportClassAssignmentBehaviorOverviewExcel(classId, assignmentId);
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
+        String className = null;
+        String assignmentName = null;
+        try {
+            com.njuzr.eaibackend.po.Class cls = classService.getClassById(classId);
+            className = cls != null ? cls.getClassName() : null;
+        } catch (Exception ignored) { }
+        try {
+            AssignmentVO vo = assignmentService.findAssignmentById(assignmentId);
+            assignmentName = vo != null ? vo.getAssignmentName() : null;
+        } catch (Exception ignored) { }
+
+        String fileName;
+        if (className == null || className.isEmpty() || assignmentName == null || assignmentName.isEmpty()) {
+            fileName = String.format("行为数据记录_%d_%d.xlsx", classId, assignmentId);
+        } else {
+            fileName = String.format("行为数据记录_%s_%s.xlsx", className, assignmentName);
+        }
 
         headers.setContentDisposition(ContentDisposition.builder("attachment")
                 .filename(fileName, StandardCharsets.UTF_8)
@@ -238,4 +271,38 @@ public class ExportController {
                 .headers(headers)
                 .body(zipBytes);
     }
+
+    @GetMapping("/class_assignment/download")
+    public ResponseEntity<byte[]> downloadClassAssignment(@RequestParam Long classId, @RequestParam Long assignmentId) {
+        byte[] zipBytes = exportCompositionService.downloadClassAssignment(classId, assignmentId);
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
+        String className = null;
+        String assignmentName = null;
+        try {
+            com.njuzr.eaibackend.po.Class cls = classService.getClassById(classId);
+            className = cls != null ? cls.getClassName() : null;
+        } catch (Exception ignored) { }
+        try {
+            AssignmentVO vo = assignmentService.findAssignmentById(assignmentId);
+            assignmentName = vo != null ? vo.getAssignmentName() : null;
+        } catch (Exception ignored) { }
+
+        String fileName;
+        if (className == null || className.isEmpty() || assignmentName == null || assignmentName.isEmpty()) {
+            fileName = String.format("class_assignment_%d_%d_%s.zip", classId, assignmentId, new java.text.SimpleDateFormat("yyyyMMdd").format(new Date()));
+        } else {
+            fileName = String.format("%s_%s_%s.zip", className, assignmentName, new java.text.SimpleDateFormat("yyyyMMdd").format(new Date()));
+        }
+
+        ContentDisposition contentDisposition = ContentDisposition.builder("attachment")
+                .filename(fileName, StandardCharsets.UTF_8)
+                .build();
+        headers.setContentDisposition(contentDisposition);
+
+        return ResponseEntity.ok()
+                .headers(headers)
+                .body(zipBytes);
+    }
 }

src/main/java/com/njuzr/eaibackend/service/ExportBehaviorOverviewService.java

@@ -2,13 +2,20 @@ package com.njuzr.eaibackend.service;
 
 import com.njuzr.eaibackend.exception.MyException;
 import com.njuzr.eaibackend.mapper.BehaviorOverviewMapper;
+import com.njuzr.eaibackend.mapper.AssignmentMapper;
+import com.njuzr.eaibackend.mapper.ClassMapper;
 import com.njuzr.eaibackend.po.BehaviorOverview;
+import com.njuzr.eaibackend.po.Assignment;
+import com.njuzr.eaibackend.po.Class;
 import com.njuzr.eaibackend.service.ClassService;
 import com.njuzr.eaibackend.vo.BehaviorOverviewVO;
 import com.njuzr.eaibackend.vo.StudentInfoVO;
+import com.njuzr.eaibackend.utils.ZipExport;
 import java.util.stream.Collectors;
 import java.util.Set;
 import java.util.Map;
+import java.util.ArrayList;
+import java.util.List;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.ss.usermodel.Sheet;
@@ -20,7 +27,6 @@ import org.springframework.stereotype.Service;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.util.List;
 import com.njuzr.eaibackend.vo.PauseStatisticsVO;
 
 /**
@@ -33,13 +39,17 @@ public class ExportBehaviorOverviewService {
     private final BehaviorOverviewMapper behaviorOverviewMapper;
     private final UserService userService;
     private final ClassService classService;
+    private final AssignmentMapper assignmentMapper;
+    private final ClassMapper classMapper;
 
     @Autowired
-    public ExportBehaviorOverviewService(BehaviorOverviewService behaviorOverviewService, BehaviorOverviewMapper behaviorOverviewMapper, UserService userService, ClassService classService) {
+    public ExportBehaviorOverviewService(BehaviorOverviewService behaviorOverviewService, BehaviorOverviewMapper behaviorOverviewMapper, UserService userService, ClassService classService, AssignmentMapper assignmentMapper, ClassMapper classMapper) {
         this.behaviorOverviewService = behaviorOverviewService;
         this.behaviorOverviewMapper = behaviorOverviewMapper;
         this.userService = userService;
         this.classService = classService;
+        this.assignmentMapper = assignmentMapper;
+        this.classMapper = classMapper;
     }
 
     /**
@@ -64,65 +74,6 @@ public class ExportBehaviorOverviewService {
         }
     }
 
-    /**
-     * 导出指定 assignmentId 下所有学生的数据到一个 Excel
-     * Sheet1: Summary（每行一个学生概览）
-     * Sheet2..N: 每个学生一个 Events 明细表（按 studentId 命名，避免超长或重复名冲突）
-     */
-    public byte[] exportAssignmentBehaviorOverviewExcel(Long assignmentId) {
-        try (Workbook workbook = new XSSFWorkbook(); ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
-            // Summary 汇总
-            Sheet summary = workbook.createSheet("Summary");
-            int rowIdx = 0;
-            Row header = summary.createRow(rowIdx++);
-            String[] headers = new String[]{
-                    "name", "studentId", "assignmentId", "insertCount", "deleteCount", "copyCount", "copyCharacterCount", "longPauseCount"
-            };
-            for (int i = 0; i < headers.length; i++) {
-                header.createCell(i).setCellValue(headers[i]);
-            }
-
-            // 查询该作业下所有概览
-            java.util.List<BehaviorOverview> overviews = behaviorOverviewMapper.findByAssignmentId(assignmentId);
-            if (overviews != null) {
-                // 先批量拉取 studentId -> name 映射，避免 N 次查询
-                Set<Long> studentIds = overviews.stream()
-                        .map(BehaviorOverview::getStudentId)
-                        .filter(java.util.Objects::nonNull)
-                        .collect(Collectors.toSet());
-                Map<Long, String> idToName = userService.getNamesByIds(studentIds);
-                for (BehaviorOverview ov : overviews) {
-                    BehaviorOverviewVO vo = behaviorOverviewService.getBehaviorOverview(ov.getStudentId(), assignmentId);
-                    Row row = summary.createRow(rowIdx++);
-                    int col = 0;
-                    String name = idToName != null ? idToName.get(vo.getStudentId()) : null;
-                    row.createCell(col++).setCellValue(name == null ? "" : name);
-                    row.createCell(col++).setCellValue(vo.getStudentId() == null ? 0 : vo.getStudentId());
-                    row.createCell(col++).setCellValue(vo.getAssignmentId() == null ? 0 : vo.getAssignmentId());
-                    row.createCell(col++).setCellValue(vo.getInsertCount() == null ? 0 : vo.getInsertCount());
-                    row.createCell(col++).setCellValue(vo.getDeleteCount() == null ? 0 : vo.getDeleteCount());
-                    row.createCell(col++).setCellValue(vo.getCopyCount() == null ? 0 : vo.getCopyCount());
-                    row.createCell(col++).setCellValue(vo.getCopyCharacterCount() == null ? 0 : vo.getCopyCharacterCount());
-                    row.createCell(col).setCellValue(vo.getLongPauseCount() == null ? 0 : vo.getLongPauseCount());
-
-                    // 为每个学生创建一个事件明细sheet
-                    String sheetName = safeSheetName("S-" + vo.getStudentId() + "-" + (name != null ? name : "Unknown"));
-                    Sheet eventsSheet = workbook.createSheet(sheetName);
-                    createEventsSheet(eventsSheet, vo.getStudentId(), assignmentId);
-                }
-            }
-
-            for (int i = 0; i < headers.length; i++) {
-                summary.autoSizeColumn(i);
-            }
-
-            workbook.write(baos);
-            return baos.toByteArray();
-        } catch (IOException e) {
-            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "导出Excel失败" + e.getMessage());
-        }
-    }
-
     /**
      * 导出指定 assignmentId 下所有学生的停顿行为统计数据为 Excel
      * Sheet1: PauseStatistics（每行一个学生的停顿统计）
@@ -185,18 +136,18 @@ public class ExportBehaviorOverviewService {
     }
 
     /**
-     * 导出指定 classId 下所有学生的行为概览数据为 Excel
+     * 导出指定班级和作业的所有学生行为概览数据为 Excel
      * Sheet1: Summary（每行一个学生概览）
      * Sheet2..N: 每个学生一个 Events 明细表（按 studentId 命名，避免超长或重复名冲突）
      */
-    public byte[] exportClassBehaviorOverviewExcel(Long classId) {
+    public byte[] exportClassAssignmentBehaviorOverviewExcel(Long classId, Long assignmentId) {
         try (Workbook workbook = new XSSFWorkbook(); ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
             // Summary 汇总
             Sheet summary = workbook.createSheet("Summary");
             int rowIdx = 0;
             Row header = summary.createRow(rowIdx++);
             String[] headers = new String[]{
-                    "name", "studentId", "insertCount", "deleteCount", "copyCount", "copyCharacterCount", "longPauseCount"
+                    "name", "studentId", "assignmentId", "insertCount", "deleteCount", "copyCount", "copyCharacterCount", "longPauseCount"
             };
             for (int i = 0; i < headers.length; i++) {
                 header.createCell(i).setCellValue(headers[i]);
@@ -216,27 +167,25 @@ public class ExportBehaviorOverviewService {
                     Long studentId = student.getStudentId();
                     if (studentId == null) continue;
                     
-                    // 查询该学生的所有行为概览
-                    java.util.List<BehaviorOverview> overviews = behaviorOverviewMapper.findByStudentId(studentId);
-                    if (overviews != null && !overviews.isEmpty()) {
-                        for (BehaviorOverview ov : overviews) {
-                            BehaviorOverviewVO vo = behaviorOverviewService.getBehaviorOverview(studentId, ov.getAssignmentId());
-                            Row row = summary.createRow(rowIdx++);
-                            int col = 0;
-                            String name = idToName != null ? idToName.get(studentId) : student.getStuName();
-                            row.createCell(col++).setCellValue(name == null ? "" : name);
-                            row.createCell(col++).setCellValue(vo.getStudentId() == null ? 0 : vo.getStudentId());
-                            row.createCell(col++).setCellValue(vo.getInsertCount() == null ? 0 : vo.getInsertCount());
-                            row.createCell(col++).setCellValue(vo.getDeleteCount() == null ? 0 : vo.getDeleteCount());
-                            row.createCell(col++).setCellValue(vo.getCopyCount() == null ? 0 : vo.getCopyCount());
-                            row.createCell(col++).setCellValue(vo.getCopyCharacterCount() == null ? 0 : vo.getCopyCharacterCount());
-                            row.createCell(col).setCellValue(vo.getLongPauseCount() == null ? 0 : vo.getLongPauseCount());
-
-                            // 为每个学生的每个作业创建一个事件明细sheet，添加作业ID确保名称唯一
-                            String sheetName = safeSheetName("S-" + vo.getStudentId() + "-" + (name != null ? name : "Unknown") + "-A" + vo.getAssignmentId());
-                            Sheet eventsSheet = workbook.createSheet(sheetName);
-                            createEventsSheet(eventsSheet, vo.getStudentId(), vo.getAssignmentId());
-                        }
+                    // 查询该学生在指定作业的行为概览
+                    BehaviorOverviewVO vo = behaviorOverviewService.getBehaviorOverview(studentId, assignmentId);
+                    if (vo != null) {
+                        Row row = summary.createRow(rowIdx++);
+                        int col = 0;
+                        String name = idToName != null ? idToName.get(studentId) : student.getStuName();
+                        row.createCell(col++).setCellValue(name == null ? "" : name);
+                        row.createCell(col++).setCellValue(vo.getStudentId() == null ? 0 : vo.getStudentId());
+                        row.createCell(col++).setCellValue(vo.getAssignmentId() == null ? 0 : vo.getAssignmentId());
+                        row.createCell(col++).setCellValue(vo.getInsertCount() == null ? 0 : vo.getInsertCount());
+                        row.createCell(col++).setCellValue(vo.getDeleteCount() == null ? 0 : vo.getDeleteCount());
+                        row.createCell(col++).setCellValue(vo.getCopyCount() == null ? 0 : vo.getCopyCount());
+                        row.createCell(col++).setCellValue(vo.getCopyCharacterCount() == null ? 0 : vo.getCopyCharacterCount());
+                        row.createCell(col).setCellValue(vo.getLongPauseCount() == null ? 0 : vo.getLongPauseCount());
+
+                        // 为每个学生创建一个事件明细sheet
+                        String sheetName = safeSheetName(name != null ? name : "Unknown");
+                        Sheet eventsSheet = workbook.createSheet(sheetName);
+                        createEventsSheet(eventsSheet, vo.getStudentId(), assignmentId);
                     } else {
                         // 没有行为概览数据的学生
                         Row row = summary.createRow(rowIdx++);
@@ -244,6 +193,7 @@ public class ExportBehaviorOverviewService {
                         String name = idToName != null ? idToName.get(studentId) : student.getStuName();
                         row.createCell(col++).setCellValue(name == null ? "" : name);
                         row.createCell(col++).setCellValue(studentId);
+                        row.createCell(col++).setCellValue(assignmentId);
                         row.createCell(col++).setCellValue(0);
                         row.createCell(col++).setCellValue(0);
                         row.createCell(col++).setCellValue(0);
@@ -260,7 +210,95 @@ public class ExportBehaviorOverviewService {
             workbook.write(baos);
             return baos.toByteArray();
         } catch (IOException e) {
-            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "导出班级行为概览Excel失败" + e.getMessage());
+            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "导出班级作业行为概览Excel失败" + e.getMessage());
+        }
+    }
+
+    /**
+     * 导出指定班级的所有作业数据为 ZIP
+     * 每个作业一个 Excel 文件，打包成 ZIP
+     */
+    public byte[] exportClassBehaviorOverviewZip(Long classId) {
+        try {
+            // 获取班级信息
+            Class cls = classMapper.selectById(classId);
+            if (cls == null) {
+                throw MyException.create(HttpStatus.NOT_FOUND, "班级不存在");
+            }
+
+            // 获取该班级对应课程的所有作业
+            List<Assignment> assignments = assignmentMapper.selectByCourseId(cls.getCourseId());
+            if (assignments == null || assignments.isEmpty()) {
+                throw MyException.create(HttpStatus.NOT_FOUND, "该班级没有作业数据");
+            }
+
+            // 为每个作业生成 Excel 文件
+            List<ZipExport.ZipItem> zipItems = new ArrayList<>();
+            for (Assignment assignment : assignments) {
+                try {
+                    byte[] excelBytes = exportClassAssignmentBehaviorOverviewExcel(classId, assignment.getAssignmentId());
+                    String fileName = safeFileName(assignment.getAssignmentName()) + ".xlsx";
+                    zipItems.add(new ZipExport.ZipItem(fileName, excelBytes));
+                } catch (Exception e) {
+                    // 跳过生成失败的作业，继续处理其他作业
+                    continue;
+                }
+            }
+
+            if (zipItems.isEmpty()) {
+                throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "没有可导出的作业数据");
+            }
+
+            // 打包成 ZIP
+            return ZipExport.packToZip(zipItems);
+        } catch (IOException e) {
+            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "导出班级行为概览ZIP失败" + e.getMessage());
+        }
+    }
+
+    /**
+     * 导出指定作业的所有班级数据为 ZIP
+     * 每个班级一个 Excel 文件，打包成 ZIP
+     */
+    public byte[] exportAssignmentBehaviorOverviewZip(Long assignmentId) {
+        try {
+            // 获取作业信息
+            Assignment assignment = assignmentMapper.selectById(assignmentId);
+            if (assignment == null) {
+                throw MyException.create(HttpStatus.NOT_FOUND, "作业不存在");
+            }
+
+            // 获取该作业对应课程的所有班级
+            List<Class> classes = classMapper.selectList(
+                new com.baomidou.mybatisplus.core.conditions.query.QueryWrapper<Class>()
+                    .eq("course_id", assignment.getCourseId())
+            );
+            
+            if (classes == null || classes.isEmpty()) {
+                throw MyException.create(HttpStatus.NOT_FOUND, "该作业没有班级数据");
+            }
+
+            // 为每个班级生成 Excel 文件
+            List<ZipExport.ZipItem> zipItems = new ArrayList<>();
+            for (Class cls : classes) {
+                try {
+                    byte[] excelBytes = exportClassAssignmentBehaviorOverviewExcel(cls.getClassId(), assignmentId);
+                    String fileName = safeFileName(cls.getClassName()) + ".xlsx";
+                    zipItems.add(new ZipExport.ZipItem(fileName, excelBytes));
+                } catch (Exception e) {
+                    // 跳过生成失败的班级，继续处理其他班级
+                    continue;
+                }
+            }
+
+            if (zipItems.isEmpty()) {
+                throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "没有可导出的班级数据");
+            }
+
+            // 打包成 ZIP
+            return ZipExport.packToZip(zipItems);
+        } catch (IOException e) {
+            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "导出作业行为概览ZIP失败" + e.getMessage());
         }
     }
 
@@ -276,6 +314,14 @@ public class ExportBehaviorOverviewService {
         return n;
     }
 
+    private String safeFileName(String name) {
+        // 文件名不允许某些字符
+        if (name == null || name.isEmpty()) {
+            return "file";
+        }
+        return name.replaceAll("[\\/:*?\"<>|]", "-");
+    }
+
     private void createSummarySheet(Sheet sheet, BehaviorOverviewVO overview) {
         int rowIdx = 0;
         Row header = sheet.createRow(rowIdx++);
@@ -363,6 +409,4 @@ public class ExportBehaviorOverviewService {
     }
 
     // 已改为批量映射方式，不再需要单查姓名方法
-}
-
-
+}

src/main/java/com/njuzr/eaibackend/service/ExportCompositionService.java

@@ -163,23 +163,20 @@ public class ExportCompositionService {
         try {
             List<ZipExport.ZipItem> zipItems = new ArrayList<>();
             for (StudentInfoVO student : students) {
-                // 获取学生ID
                 String officialNumber = student.getOfficialNumber();
                 User user = userMapper.selectOne(new QueryWrapper<User>().eq("official_number", officialNumber));
                 if (user == null) {
                     continue;
                 }
                 Long studentId = user.getId();
-                String studentDir = user.getOfficialNumber() + "_" + user.getName() + "/";
                 
-                // 对每个作业，获取学生的提交历史
                 for (Assignment assignment : courseAssignments) {
                     Long assignmentId = assignment.getAssignmentId();
+                    String assignmentDir = assignment.getAssignmentName() + "/";
+                    String studentDir = assignmentDir + user.getOfficialNumber() + "_" + user.getName() + "/";
                     try {
-                        // 获取作业历史记录
                         List<EngagementHistoryVO> historyList = assignmentService.getEngagementHistory(studentId, assignmentId);
                         for (EngagementHistoryVO history : historyList) {
-                            // 生成Word文档
                             Map<String, Object> model = new HashMap<>();
                             model.put("title", assignment.getAssignmentName());
                             model.put("studentName", user.getName());
@@ -193,7 +190,6 @@ public class ExportCompositionService {
                             zipItems.add(new ZipExport.ZipItem(fileName, wordBytes));
                         }
                     } catch (Exception e) {
-                        // 学生可能未提交该作业，跳过
                         log.warn("学生 {} 未提交作业 {}，跳过", studentId, assignmentId);
                     }
                 }
@@ -205,31 +201,87 @@ public class ExportCompositionService {
     }
 
     public byte[] downloadAssignmentSubmissions(Long assignmentId) {
-        // 获取作业信息
         AssignmentVO assignment = assignmentService.findAssignmentById(assignmentId);
         if (assignment == null) {
             throw MyException.create(HttpStatus.BAD_REQUEST, "作业不存在");
         }
 
-        // 获取所有提交该作业的学生
-        List<Engagement> engagements = engagementMapperServiceImpl.getEngagementByAssignmentId(assignmentId);
-        if (engagements.isEmpty()) {
-            throw MyException.create(HttpStatus.BAD_REQUEST, "无学生提交该作业");
+        Long courseId = assignment.getCourseId();
+        List<com.njuzr.eaibackend.po.Class> courseClasses = classService.select(courseId);
+        if (courseClasses.isEmpty()) {
+            throw MyException.create(HttpStatus.BAD_REQUEST, "课程无班级");
         }
 
-        // 生成ZIP文件
         try {
             List<ZipExport.ZipItem> zipItems = new ArrayList<>();
-            for (Engagement engagement : engagements) {
-                Long studentId = engagement.getStudentId();
-                // 获取学生信息
-                UserVO user = userService.searchUsers(new Page<>(1, 1), studentId, null, null, null).getRecords().get(0);
-                String studentDir = user.getOfficialNumber() + "_" + user.getName() + "/";
+            
+            for (com.njuzr.eaibackend.po.Class cls : courseClasses) {
+                String className = cls.getClassName();
+                String classDir = className + "/";
+                
+                List<StudentInfoVO> students = classService.getStudentsByClassId(cls.getClassId());
+                for (StudentInfoVO student : students) {
+                    String officialNumber = student.getOfficialNumber();
+                    User user = userMapper.selectOne(new QueryWrapper<User>().eq("official_number", officialNumber));
+                    if (user == null) continue;
+                    
+                    Long studentId = user.getId();
+                    String studentDir = classDir + user.getOfficialNumber() + "_" + user.getName() + "/";
+                    
+                    List<EngagementHistoryVO> historyList = assignmentService.getEngagementHistory(studentId, assignmentId);
+                    for (EngagementHistoryVO history : historyList) {
+                        Map<String, Object> model = new HashMap<>();
+                        model.put("title", assignment.getAssignmentName());
+                        model.put("studentName", user.getName());
+                        model.put("officialNumber", user.getOfficialNumber());
+                        model.put("assignmentName", assignment.getAssignmentName());
+                        model.put("date", history.getSubmitTime());
+                        model.put("content", processContent(history.getTextContent()));
+                        
+                        byte[] wordBytes = wordExporter.exportCompositionWord(model);
+                        String fileName = studentDir + user.getOfficialNumber() + "_" + user.getName() + "_版本" + history.getVersion() + ".docx";
+                        zipItems.add(new ZipExport.ZipItem(fileName, wordBytes));
+                    }
+                }
+            }
+            return ZipExport.packToZip(zipItems);
+        } catch (IOException e) {
+            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "ZIP打包失败" + e.getMessage());
+        }
+    }
+
+    public byte[] downloadClassAssignment(Long classId, Long assignmentId) {
+        com.njuzr.eaibackend.po.Class cls = classService.getClassById(classId);
+        if (cls == null) {
+            throw MyException.create(HttpStatus.BAD_REQUEST, "班级不存在");
+        }
+        
+        AssignmentVO assignment = assignmentService.findAssignmentById(assignmentId);
+        if (assignment == null) {
+            throw MyException.create(HttpStatus.BAD_REQUEST, "作业不存在");
+        }
+        
+        String folderName = cls.getClassName() + "_" + assignment.getAssignmentName();
+        String folderDir = folderName + "/";
+        
+        List<StudentInfoVO> students = classService.getStudentsByClassId(classId);
+        if (students.isEmpty()) {
+            throw MyException.create(HttpStatus.BAD_REQUEST, "班级无学生");
+        }
+        
+        try {
+            List<ZipExport.ZipItem> zipItems = new ArrayList<>();
+            
+            for (StudentInfoVO student : students) {
+                String officialNumber = student.getOfficialNumber();
+                User user = userMapper.selectOne(new QueryWrapper<User>().eq("official_number", officialNumber));
+                if (user == null) continue;
+                
+                Long studentId = user.getId();
+                String studentDir = folderDir + user.getOfficialNumber() + "_" + user.getName() + "/";
                 
-                // 获取作业历史记录
                 List<EngagementHistoryVO> historyList = assignmentService.getEngagementHistory(studentId, assignmentId);
                 for (EngagementHistoryVO history : historyList) {
-                    // 生成Word文档
                     Map<String, Object> model = new HashMap<>();
                     model.put("title", assignment.getAssignmentName());
                     model.put("studentName", user.getName());