fix(ci): 构建容器名唯一化 + npm 走国内镜像源（避免并发互踩 exit 137）

.gitea/workflows/build.yml

@@ -25,7 +25,10 @@ jobs:
       options: --network infra-infra-net
     steps:
       - name: 安装 git / curl（alpine）
-        run: apk add --no-cache git curl
+        run: |
+          # 统一走 aliyun 源：dl-cdn 时段性被拦会卡满 60s×2（2026-10-20 事故）
+          sed -i 's#dl-cdn.alpinelinux.org#mirrors.aliyun.com#g' /etc/apk/repositories
+          apk add --no-cache git curl
 
       # 内网 Gitea 无法访问 GitHub 拉 actions/checkout，手动 clone 本仓库
       - name: 拉取源码（内网无 GitHub，手动 clone 本仓库）
@@ -55,18 +58,24 @@ jobs:
       - name: 构建 jar（maven 容器，复用宿主 m2 缓存）
         run: |
           set -e
-          docker rm -f mavenbuild 2>/dev/null || true
+          # 构建容器名必须全局唯一：runner 挂的是宿主 docker.sock，容器名在整个 daemon 上共享
-          docker run -d --name mavenbuild \
+          # 命名空间。固定名会在多仓/多条 workflow 并发时互相 docker rm -f 掉对方正在构建的
+          # 容器，表现为无编译报错的 exit 137（SIGKILL，2026-10-21 实测复现）。
+          # GITHUB_RUN_ID 实例级唯一，再拼时间戳兜底。
+          BUILD_CONTAINER="mavenbuild-${GITHUB_RUN_ID:-0}-$(date +%s)"
+          echo "BUILD_CONTAINER=${BUILD_CONTAINER}"
+          docker rm -f "$BUILD_CONTAINER" 2>/dev/null || true
+          docker run -d --name "$BUILD_CONTAINER" \
             --network infra-infra-net \
             -v /opt/docker/projman-m2:/root/.m2 \
             -w /build maven:3.6.3-jdk-8 sleep 3600
-          docker cp "${PWD}/." mavenbuild:/build/
+          docker cp "${PWD}/." "$BUILD_CONTAINER":/build/
-          docker exec mavenbuild sh -c "printf '%s' '<settings><profiles><profile><id>nexus-repo</id><repositories><repository><id>nexus-internal</id><url>http://nexus:8081/repository/maven-public/</url><releases><enabled>true</enabled></releases><snapshots><enabled>true</enabled><updatePolicy>always</updatePolicy></snapshots></repository></repositories></profile></profiles><activeProfiles><activeProfile>nexus-repo</activeProfile></activeProfiles></settings>' > /root/.m2/settings.xml"
+          docker exec "$BUILD_CONTAINER" sh -c "printf '%s' '<settings><profiles><profile><id>nexus-repo</id><repositories><repository><id>nexus-internal</id><url>http://nexus:8081/repository/maven-public/</url><releases><enabled>true</enabled></releases><snapshots><enabled>true</enabled><updatePolicy>always</updatePolicy></snapshots></repository></repositories></profile></profiles><activeProfiles><activeProfile>nexus-repo</activeProfile></activeProfiles></settings>' > /root/.m2/settings.xml"
-          docker exec mavenbuild sh -c 'cd /build && mvn -B -DskipTests clean package'
+          docker exec "$BUILD_CONTAINER" sh -c 'cd /build && mvn -B -DskipTests clean package'
-          docker exec mavenbuild sh -c 'cd /build/target && cp *.jar app.jar'
+          docker exec "$BUILD_CONTAINER" sh -c 'cd /build/target && cp *.jar app.jar'
           mkdir -p "${PWD}/target"
-          docker cp mavenbuild:/build/target/app.jar "${PWD}/target/app.jar"
+          docker cp "$BUILD_CONTAINER":/build/target/app.jar "${PWD}/target/app.jar"
-          docker rm -f mavenbuild
+          docker rm -f "$BUILD_CONTAINER"
 
       - name: 构建并推送镜像
         run: |

src/main/java/com/yunhai/homework/model/homework/HomeworkQuery.java

@@ -20,6 +20,16 @@ public class HomeworkQuery extends BasePageQuery {
     /** 状态过滤：null 不过滤；1 已发布 */
     private Integer status;
 
+    /**
+     * 状态过滤（前端 Tab，旧四态派生值）：all 全部 / collecting 收集中 / closed 已截止 /
+     * done 已完成 / draft 草稿。口径与列表返回的 hwStatus 派生规则一致，
+     * null/空/未知值不过滤。
+     */
+    private String hwStatus;
+
+    /** 学科过滤（字典编码，与 homework.subject 精确匹配） */
+    private String subject;
+
     /** 类型过滤：1 普通 / 2 重要 */
     private Integer type;
 

src/main/java/com/yunhai/homework/model/homework/HomeworkVo.java

@@ -48,6 +48,9 @@ public class HomeworkVo {
     /** 接收人列表（JSON） */
     private String receiveList;
 
+    /** 班级展示文本（年级名前缀，如「高一1班、高一2班」；前端「班级」列直接展示） */
+    private String receiveText;
+
     /** 附件ID串（"1,2,3"，列表页下载入口使用；对齐旧 .NET UpFile 字段） */
     private String UpFile;
 

src/main/java/com/yunhai/homework/service/impl/HomeworkService.java

@@ -95,6 +95,9 @@ public class HomeworkService implements IHomeworkService {
     @Autowired
     private SubjectDictService subjectDictService;
 
+    @Autowired
+    private RosterService rosterService;
+
     private static final int PUBLISHED = HomeworkStatusEnum.PUBLISHED.getCode();
 
     // ============================ 发作业 ============================
@@ -338,11 +341,43 @@ public class HomeworkService implements IHomeworkService {
                 List<Integer> fids = fileMap.getOrDefault(vo.getId(), Collections.emptyList());
                 vo.setUpFile(fids.stream().map(String::valueOf).collect(Collectors.joining(",")));
             }
+            fillReceiveText(content);
             fillProgress(content);
         }
         return PageUtils.toResult(new PageImpl<>(content, pageable, page.getTotalElements()));
     }
 
+    /**
+     * 批量回填列表页「班级」列展示文本（年级名前缀，如「高一1班、高一2班」）：
+     * receiveList 为 ALL/空 → 「全部班级」；其余按 homework_class 关联实时解析
+     * （RosterService 映射含年级前缀），班级名快照兜底、再退班级ID；一次批量查询 + 一次 bschclass 外呼。
+     * 无班级关联的行保持 null（前端回退「-」）。
+     */
+    private void fillReceiveText(List<HomeworkVo> content) {
+        List<Integer> homeworkIds = content.stream().map(HomeworkVo::getId).collect(Collectors.toList());
+        Map<Integer, List<HomeworkClass>> byHw = homeworkClassRepository.findByHomeworkIds(homeworkIds).stream()
+                .collect(Collectors.groupingBy(HomeworkClass::getHomeworkId));
+        Map<Integer, String> classNames = rosterService.classNames(byHw.values().stream()
+                .flatMap(List::stream)
+                .map(HomeworkClass::getClassId)
+                .distinct()
+                .collect(Collectors.toList()));
+        for (HomeworkVo vo : content) {
+            String rl = vo.getReceiveList();
+            if (rl == null || rl.trim().isEmpty() || "ALL".equalsIgnoreCase(rl.trim())) {
+                vo.setReceiveText("全部班级");
+                continue;
+            }
+            List<HomeworkClass> classes = byHw.getOrDefault(vo.getId(), Collections.emptyList());
+            if (classes.isEmpty()) {
+                continue;
+            }
+            vo.setReceiveText(classes.stream()
+                    .map(c -> RosterService.displayOr(classNames.get(c.getClassId()), c.getClassName(), c.getClassId()))
+                    .collect(Collectors.joining("、")));
+        }
+    }
+
     /**
      * 批量回填列表页提交/批改进度（「全部作业」页的 提交进度 / 未读未交 / 批改 列）。
      * <p>口径与 V2 一致：草稿两态与仅查阅型作业不计（progress 保持 null，前端显示「—」）；
@@ -413,12 +448,16 @@ public class HomeworkService implements IHomeworkService {
         if (StringUtils.hasText(query.getKeyword())) {
             predicates.add(cb.like(root.get("title"), "%" + query.getKeyword() + "%"));
         }
+        if (StringUtils.hasText(query.getSubject())) {
+            predicates.add(cb.equal(root.get("subject"), query.getSubject()));
+        }
         if (query.getType() != null) {
             predicates.add(cb.equal(root.get("type"), query.getType()));
         }
         if (StringUtils.hasText(query.getDeptId())) {
             predicates.add(cb.equal(root.get("deptId"), query.getDeptId()));
         }
+        appendLegacyHwStatus(query.getHwStatus(), root, cb, predicates);
         // 前端传 yyyy-MM-dd 短日期：startTime 当天 00:00:00 起，endTime 补全到当天 23:59:59
         if (query.getStartTime() != null) {
             predicates.add(cb.greaterThanOrEqualTo(root.get("createTime"), query.getStartTime().atStartOfDay()));
@@ -428,6 +467,46 @@ public class HomeworkService implements IHomeworkService {
         }
     }
 
+    /**
+     * 状态过滤（前端 Tab 的旧四态值 all/collecting/closed/done/draft），口径与
+     * {@link #legacyHwStatus(Homework)} 派生规则一致，保证「展示什么状态就筛出什么状态」：
+     * draft/collecting 兼容存量 hw_status 为空的行（按定时发送时间是否到点判定），
+     * closed/done 直接等值；null/空/all/未知值不过滤。
+     */
+    private static void appendLegacyHwStatus(String hwStatus, Root<Homework> root, CriteriaBuilder cb,
+                                             List<Predicate> predicates) {
+        if (!StringUtils.hasText(hwStatus) || "all".equalsIgnoreCase(hwStatus.trim())) {
+            return;
+        }
+        LocalDateTime now = LocalDateTime.now();
+        switch (hwStatus.trim()) {
+            case "draft":
+                predicates.add(cb.or(
+                        root.get("hwStatus").in(Arrays.asList(
+                                HwStatusEnum.DRAFT_UNPUBLISHED.getCode(), HwStatusEnum.DRAFT_SCHEDULED.getCode())),
+                        cb.and(cb.isNull(root.get("hwStatus")),
+                                cb.isNotNull(root.get("timingSendTime")),
+                                cb.greaterThan(root.get("timingSendTime"), now))));
+                break;
+            case "collecting":
+                predicates.add(cb.or(
+                        cb.equal(root.get("hwStatus"), HwStatusEnum.PUBLISHED.getCode()),
+                        cb.and(cb.isNull(root.get("hwStatus")),
+                                cb.or(cb.isNull(root.get("timingSendTime")),
+                                        cb.lessThanOrEqualTo(root.get("timingSendTime"), now)))));
+                break;
+            case "closed":
+                predicates.add(cb.equal(root.get("hwStatus"), HwStatusEnum.CLOSED.getCode()));
+                break;
+            case "done":
+                predicates.add(cb.equal(root.get("hwStatus"), HwStatusEnum.ARCHIVED.getCode()));
+                break;
+            default:
+                // 未知值按不过滤处理（同 all），避免前后端值不一致时列表误清空
+                break;
+        }
+    }
+
     // ============================ 详情（顺带标记已读） ============================
 
     @Override
@@ -889,23 +968,19 @@ public class HomeworkService implements IHomeworkService {
     }
 
     /**
-     * 接收对象可读文本：优先用 homework_class 的班级名快照（"高一(1)班、高一(2)班"）。
+     * 接收对象可读文本（年级名前缀，如「高一(1)班、高一(2)班」）：实时解析
-     * 快照缺失时退回 id 串，保证「接收班级」标签不显示空白。
+     * （RosterService 映射含年级前缀），班级名快照兜底、再退 id 串，保证「接收班级」标签不显示空白。
      */
     private String receiveText(Integer homeworkId) {
         List<HomeworkClass> classes = homeworkClassRepository.findByHomeworkId(homeworkId);
         if (classes.isEmpty()) {
             return null;
         }
-        String names = classes.stream()
+        Map<Integer, String> classNames = rosterService.classNames(classes.stream()
-                .map(HomeworkClass::getClassName)
+                .map(HomeworkClass::getClassId)
-                .filter(StringUtils::hasText)
+                .collect(Collectors.toList()));
-                .collect(Collectors.joining("、"));
-        if (StringUtils.hasText(names)) {
-            return names;
-        }
         return classes.stream()
-                .map(c -> String.valueOf(c.getClassId()))
+                .map(c -> RosterService.displayOr(classNames.get(c.getClassId()), c.getClassName(), c.getClassId()))
                 .collect(Collectors.joining("、"));
     }
 

src/main/java/com/yunhai/homework/service/impl/RosterService.java

@@ -1,6 +1,7 @@
 package com.yunhai.homework.service.impl;
 
 import com.yunhai.homework.model.bsch.SchClassDto;
+import com.yunhai.homework.model.bsch.SchGradeDto;
 import com.yunhai.homework.model.bsch.SchInfoDto;
 import com.yunhai.homework.model.bsch.SchStudentDto;
 import com.yunhai.homework.service.IClassService;
@@ -88,7 +89,8 @@ public class RosterService {
     }
 
     /**
-     * 班级ID → 班级名（bschclass GetVClassList 映射）。
+     * 班级ID → 班级展示名（bschclass GetVClassList 映射，前缀年级名，如「高一1班」；
+     * 班级名已含年级前缀时不重复拼接）。年级列表拉取失败时退化为原班级名，
      * 远端不可用或无学校身份时降级为空映射，由调用方回退班级ID展示，不阻断名单本身。
      */
     public Map<Integer, String> classNames(Collection<Integer> classIds) {
@@ -102,19 +104,25 @@ public class RosterService {
                 return names;
             }
             Set<Integer> pending = new LinkedHashSet<>(classIds);
+            Map<Integer, SchClassDto> matched = new LinkedHashMap<>();
             for (SchClassDto c : classService.getSchClassList(schSerId)) {
                 if (c != null && c.getClassId() != null && pending.remove(c.getClassId())
                         && StringUtils.hasText(c.getClassName())) {
-                    names.put(c.getClassId(), c.getClassName());
+                    matched.put(c.getClassId(), c);
                 }
             }
+            Map<Integer, String> grades = matched.isEmpty() ? Collections.emptyMap() : gradeNames(schSerId);
+            for (Map.Entry<Integer, SchClassDto> e : matched.entrySet()) {
+                SchClassDto c = e.getValue();
+                names.put(e.getKey(), displayName(c.getClassName(), c.getGradeId(), grades));
+            }
         } catch (BizException e) {
             log.warn("[roster] 班级名称映射失败, 回退班级ID展示: {}", e.getMessage());
         }
         return names;
     }
 
-    /** 班级ID → 班级名（单班便捷方法，缺失回退班级ID） */
+    /** 班级ID → 班级展示名（单班便捷方法，缺失回退班级ID） */
     public String className(Integer classId) {
         if (classId == null) {
             return null;
@@ -123,6 +131,45 @@ public class RosterService {
         return StringUtils.hasText(name) ? name : String.valueOf(classId);
     }
 
+    /**
+     * 班级展示名合成：年级名 + 班级名（如「高一」+「1班」=「高一1班」），
+     * 班级名已以年级名开头时不重复拼接；缺年级或无班级名时原样返回。
+     */
+    public static String displayName(String className, Integer gradeId, Map<Integer, String> gradeNames) {
+        if (!StringUtils.hasText(className) || gradeId == null
+                || gradeNames == null || gradeNames.isEmpty()) {
+            return className;
+        }
+        String gradeName = gradeNames.get(gradeId);
+        if (!StringUtils.hasText(gradeName) || className.startsWith(gradeName)) {
+            return className;
+        }
+        return gradeName + className;
+    }
+
+    /** 列表展示名兜底：实时名（含年级前缀）优先，其次班级名快照，最后班级ID */
+    public static String displayOr(String liveName, String snapshotName, Integer classId) {
+        if (StringUtils.hasText(liveName)) {
+            return liveName;
+        }
+        return StringUtils.hasText(snapshotName) ? snapshotName : String.valueOf(classId);
+    }
+
+    /** 年级ID → 年级名（bschclass GetSchLenLevellist；失败降级空映射，仅退化为不带年级前缀） */
+    private Map<Integer, String> gradeNames(String schSerId) {
+        Map<Integer, String> names = new LinkedHashMap<>();
+        try {
+            for (SchGradeDto g : classService.getSchGradeList(schSerId)) {
+                if (g != null && g.getId() != null && StringUtils.hasText(g.getName())) {
+                    names.put(g.getId(), g.getName());
+                }
+            }
+        } catch (BizException e) {
+            log.warn("[roster] 年级列表拉取失败, 班级名退化为不带年级前缀: {}", e.getMessage());
+        }
+        return names;
+    }
+
     /**
      * 当前登录学生所在班级条目（实时 bschclass 全校学生按登录人用户ID过滤）。
      * 学生ID = 登录人用户中心数字ID；一人多班各一条。

src/main/java/com/yunhai/homework/service/impl/StudentHomeworkService.java

@@ -158,9 +158,7 @@ public class StudentHomeworkService {
         vo.setDescription(homework.getContent());
         vo.setAttachments(homeworkAttachmentRepository.findByHomeworkIdOrderBySortAscIdAsc(id).stream()
                 .map(this::toAttachmentItem).collect(Collectors.toList()));
-        vo.setClasses(homeworkClassRepository.findByHomeworkId(id).stream()
+        vo.setClasses(classDisplayItems(homeworkClassRepository.findByHomeworkId(id)));
-                .map(c -> new ClassItem(c.getClassId(), c.getClassName()))
-                .collect(Collectors.toList()));
         if (latest != null) {
             vo.setMyText(latest.getText());
             vo.setMyAttachments(submissionAttachmentRepository
@@ -408,6 +406,19 @@ public class StudentHomeworkService {
         return vo;
     }
 
+    /**
+     * 参与班级条目：展示名实时解析（bschclass 映射，含年级前缀），
+     * 实时名缺失回退作业上的班级名快照，再退班级ID。
+     */
+    private List<ClassItem> classDisplayItems(List<HomeworkClass> classes) {
+        Map<Integer, String> classNames = rosterService.classNames(
+                classes.stream().map(HomeworkClass::getClassId).collect(Collectors.toList()));
+        return classes.stream()
+                .map(c -> new ClassItem(c.getClassId(),
+                        RosterService.displayOr(classNames.get(c.getClassId()), c.getClassName(), c.getClassId())))
+                .collect(Collectors.toList());
+    }
+
     private void copyBase(StudentHomeworkVo vo, Homework h, HomeworkSubmission latest,
                           Map<String, String> subjectNames) {
         vo.setId(h.getId());

src/main/java/com/yunhai/homework/service/impl/TeacherHomeworkV2Service.java

@@ -258,7 +258,10 @@ public class TeacherHomeworkV2Service {
                         query),
                 PageUtils.toPageable(query, sort == null ? Sort.by(Sort.Direction.DESC, "updateTime") : sort));
         Map<String, String> subjectNames = subjectDictService.nameMap();
-        return PageUtils.toResult(page.map(h -> toVo(h, false, false, subjectNames)));
+        Map<Integer, List<HomeworkClass>> classesByHw = classesByHomework(page.getContent());
+        Map<Integer, String> classNames = rosterService.classNames(allClassIds(classesByHw));
+        return PageUtils.toResult(page.map(h -> toVo(h, false, false, subjectNames,
+                classesByHw.getOrDefault(h.getId(), Collections.emptyList()), classNames)));
     }
 
     // ============================ 页 3：已发布列表 ============================
@@ -276,7 +279,10 @@ public class TeacherHomeworkV2Service {
                 ownedStatusSpec(UserContext.getUserId(), statuses, query),
                 PageUtils.toPageable(query, sort == null ? Sort.by(Sort.Direction.DESC, "publishedAt") : sort));
         Map<String, String> subjectNames = subjectDictService.nameMap();
-        return PageUtils.toResult(page.map(h -> toVo(h, false, true, subjectNames)));
+        Map<Integer, List<HomeworkClass>> classesByHw = classesByHomework(page.getContent());
+        Map<Integer, String> classNames = rosterService.classNames(allClassIds(classesByHw));
+        return PageUtils.toResult(page.map(h -> toVo(h, false, true, subjectNames,
+                classesByHw.getOrDefault(h.getId(), Collections.emptyList()), classNames)));
     }
 
     private Specification<Homework> ownedStatusSpec(Integer publisherId, List<String> statuses, TeacherHomeworkQuery query) {
@@ -396,7 +402,10 @@ public class TeacherHomeworkV2Service {
     @Transactional(readOnly = true)
     public HomeworkV2Vo detail(Integer id) {
         Homework homework = stateService.requireOwned(id, UserContext.getUserId());
-        return toVo(homework, true, !HwStatusEnum.of(homework.getHwStatus()).isDraft(), subjectDictService.nameMap());
+        List<HomeworkClass> classes = homeworkClassRepository.findByHomeworkId(id);
+        Map<Integer, String> classNames = rosterService.classNames(classIds(classes));
+        return toVo(homework, true, !HwStatusEnum.of(homework.getHwStatus()).isDraft(),
+                subjectDictService.nameMap(), classes, classNames);
     }
 
     /**
@@ -934,7 +943,7 @@ public class TeacherHomeworkV2Service {
         return ids;
     }
 
-    /** 学校年级ID → 年级名（bschclass GetSchLenLevellist；远端失败降级空映射，班级归入「未分组」） */
+    /** 学校年级ID → 年级名（bschclass GetSchLenLevellist；远端失败降级空映射，班级归入「未分组」/不带前缀） */
     private Map<Integer, String> gradeNames(String schSerId) {
         Map<Integer, String> names = new java.util.LinkedHashMap<>();
         try {
@@ -944,7 +953,7 @@ public class TeacherHomeworkV2Service {
                 }
             }
         } catch (BizException e) {
-            log.warn("[classTree] 年级列表拉取失败, 降级「未分组」展示: {}", e.getMessage());
+            log.warn("[gradeNames] 年级列表拉取失败, 降级不带年级前缀展示: {}", e.getMessage());
         }
         return names;
     }
@@ -1011,12 +1020,14 @@ public class TeacherHomeworkV2Service {
         if (classIds.isEmpty()) {
             return new ArrayList<>();
         }
+        Map<Integer, String> gradeNames = gradeNames(schSerId);
         List<TeachingClassVo> result = new ArrayList<>();
         try {
             for (SchClassDto schClass : classService.getSchClassList(schSerId)) {
                 Integer classId = schClass.getClassId();
                 if (classId != null && classIds.remove(classId)) {
-                    result.add(teachingClassVo(classId, schClass.getClassName()));
+                    result.add(teachingClassVo(classId, RosterService.displayName(
+                            schClass.getClassName(), schClass.getGradeId(), gradeNames)));
                 }
             }
         } catch (BizException e) {
@@ -1113,7 +1124,8 @@ public class TeacherHomeworkV2Service {
     // ============================ VO 组装 ============================
 
     private HomeworkV2Vo toVo(Homework h, boolean withAttachments, boolean withProgress,
-                              Map<String, String> subjectNames) {
+                              Map<String, String> subjectNames, List<HomeworkClass> classes,
+                              Map<Integer, String> classNames) {
         HomeworkV2Vo vo = new HomeworkV2Vo();
         vo.setId(h.getId());
         vo.setTitle(h.getTitle());
@@ -1130,8 +1142,10 @@ public class TeacherHomeworkV2Service {
         vo.setAllowLate(h.getAllowLate());
         vo.setRemind1d(h.getRemind1d());
         vo.setRemind1h(h.getRemind1h());
-        vo.setClasses(homeworkClassRepository.findByHomeworkId(h.getId()).stream()
+        // 班级展示名实时解析（含年级前缀），存量快照仅作兜底
-                .map(c -> new ClassItem(c.getClassId(), c.getClassName()))
+        vo.setClasses(classes.stream()
+                .map(c -> new ClassItem(c.getClassId(),
+                        RosterService.displayOr(classNames.get(c.getClassId()), c.getClassName(), c.getClassId())))
                 .collect(Collectors.toList()));
         if (withAttachments) {
             vo.setAttachments(homeworkAttachmentRepository.findByHomeworkIdOrderBySortAscIdAsc(h.getId()).stream()
@@ -1150,11 +1164,31 @@ public class TeacherHomeworkV2Service {
         vo.setCreateTime(h.getCreateTime());
         vo.setUpdateTime(h.getUpdateTime());
         if (withProgress && !HwStatusEnum.of(h.getHwStatus()).isDraft()) {
-            vo.setProgress(progressCalculator.compute(h.getId(), classIds(homeworkClassRepository.findByHomeworkId(h.getId()))).total);
+            vo.setProgress(progressCalculator.compute(h.getId(), classIds(classes)).total);
         }
         return vo;
     }
 
+    /**
+     * 页内作业的班级关联分组（findByHomeworkIds 批量一次查询，避免逐行 N+1）。
+     */
+    private Map<Integer, List<HomeworkClass>> classesByHomework(List<Homework> homeworks) {
+        List<Integer> ids = homeworks.stream().map(Homework::getId).collect(Collectors.toList());
+        if (ids.isEmpty()) {
+            return Collections.emptyMap();
+        }
+        return homeworkClassRepository.findByHomeworkIds(ids).stream()
+                .collect(Collectors.groupingBy(HomeworkClass::getHomeworkId));
+    }
+
+    private static List<Integer> allClassIds(Map<Integer, List<HomeworkClass>> classesByHw) {
+        return classesByHw.values().stream()
+                .flatMap(List::stream)
+                .map(HomeworkClass::getClassId)
+                .distinct()
+                .collect(Collectors.toList());
+    }
+
     // ============================ 名册辅助 ============================
 
     /** 参与班级在班学生 id 集合（实时 bschclass 名册） */