1.fix empty list in cache

luoo_music/src/main/java/com/luoo/music/service/JournalService.java

@@ -1,6 +1,7 @@
 package com.luoo.music.service;
 
 import java.util.*;
+import java.util.function.Function;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import javax.persistence.criteria.CriteriaBuilder;
@@ -14,6 +15,8 @@ import constants.Constants;
 import enums.JournalPublishEnum;
 import enums.JournalStatusEnum;
 import net.oschina.j2cache.CacheChannel;
+import net.oschina.j2cache.CacheObject;
+
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang3.tuple.Pair;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -354,18 +357,33 @@ public class JournalService {
 		return journalSongDao.orderByJournalIdField(jouranlIds);
 	}
 	
-	@SuppressWarnings("unchecked")
 	public List<JournalRespDTO> queryJournalByPage(JournalQueryReq queryReq) {
 		if(StringTools.isEmpty(queryReq.getCategoryId())&&StringTools.isEmpty(queryReq.getJournalNoRange())) { 
-		    return (List<JournalRespDTO>) this.cacheChannel.get(Constants.J2CACHE_REGION_JOURNAL_QUERY_PAGE, queryReq.toString(), key -> getJournalRespDTOWithComment(queryReq) , false).getValue() ;
+			return queryJournalByPage(queryReq, key -> getJournalRespDTOWithComment(queryReq));
 		}
-		List<JournalRespDTO> list= (List<JournalRespDTO>) this.cacheChannel.get(Constants.J2CACHE_REGION_JOURNAL_QUERY_PAGE, queryReq.toString(), key -> getJournalRespDTO(queryReq) , false).getValue() ;
+		List<JournalRespDTO> list= queryJournalByPage(queryReq,key -> getJournalRespDTO(queryReq)) ;
 		list.parallelStream().forEach(j->{
 			updateComment(j);
 		});
 		return list;
 	}
 
+	@SuppressWarnings("unchecked")
+	private List<JournalRespDTO> queryJournalByPage(JournalQueryReq queryReq,
+			Function<JournalQueryReq, List<JournalRespDTO>> function) {
+		CacheObject cacheObject=this.cacheChannel.get(Constants.J2CACHE_REGION_JOURNAL_QUERY_PAGE, queryReq.toString());
+		if(null==cacheObject||null==cacheObject.getValue()) {
+			List<JournalRespDTO> result = function.apply(queryReq);
+			if(CollectionUtils.isEmpty(result)) {
+				return Collections.emptyList();
+			}
+			this.cacheChannel.set(Constants.J2CACHE_REGION_JOURNAL_QUERY_PAGE, queryReq.toString(), result);
+			return result;
+		}
+		return (List<JournalRespDTO>) cacheObject.getValue();
+	}
+
+
 	private void updateComment(JournalRespDTO journalRespDTO) {
 		CommentDTO commentDTO = CommentMapper.getCommentDTO(journalRespDTO.getId(), mongoTemplate, commentDao,
 				redisTemplate,userClient,cacheChannel);