fix 学生列表翻页错误问题

mec-biz/src/main/java/com/ym/mec/biz/service/impl/StudentManageServiceImpl.java

@@ -447,7 +447,7 @@ public class StudentManageServiceImpl implements StudentManageService {
         PageInfo<MusicGroupStudentsDto> pageInfo = new PageInfo<>(queryInfo.getPage(), queryInfo.getRows());
         Map<String, Object> params = new HashMap<>();
         MapUtil.populateMap(params, queryInfo);
-        List<MusicGroupStudentsDto> dataList = null;
+        List<MusicGroupStudentsDto> dataList = new ArrayList<>();
         List<StudentRegistration> studentRegistrations = studentRegistrationDao.getMusicGroupStu(queryInfo.getMusicGroupId());
         if(studentRegistrations.size() == 0){
             return pageInfo;
@@ -478,8 +478,8 @@ public class StudentManageServiceImpl implements StudentManageService {
         if (queryInfo.getIsExport() && count > 50000) {
             throw new BizException("数据集太大，不能导出.最大数据集不能超过50000");
         }
-        if (count > 0) {
-            pageInfo.setTotal(count);
+        pageInfo.setTotal(count);
+        if (queryInfo.getPage() <= pageInfo.getTotalPage()) {
             params.put("offset", pageInfo.getOffset());
             dataList = studentManageDao.queryMusicGroupStudent(params);
             //获取乐团学员欠费金额
@@ -502,9 +502,6 @@ public class StudentManageServiceImpl implements StudentManageService {
                 e.setNoPaymentAmount(totalAmountMap.get(e.getUserId()));
             });
         }
-        if (count == 0) {
-            dataList = new ArrayList<>();
-        }
         pageInfo.setRows(dataList);
         return pageInfo;
     }