修改重考和导出的bug

examcloud-core-oe-admin-service/src/main/java/cn/com/qmth/examcloud/core/oe/admin/service/bean/examrecord/ExamRecordEntityConvert.java

@@ -31,6 +31,7 @@ import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Component;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -156,6 +157,9 @@ public class ExamRecordEntityConvert {
 
     
     public List<ExamRecordInfo> of(List<ExamRecordDataEntity> entities) {
+        if (entities==null || entities.isEmpty()){
+            return new ArrayList<ExamRecordInfo>();
+        }
     	//缓存
         Map<String,Object> cahcheMap = new HashMap<String, Object>();
         List<ExamRecordInfo> list = entities.stream().map(entity -> of(entity,cahcheMap)).collect(Collectors.toList());