diff --git a/src/main/java/run/halo/app/controller/content/ContentArchiveController.java b/src/main/java/run/halo/app/controller/content/ContentArchiveController.java
index 5da4b1554..f54db97a5 100644
--- a/src/main/java/run/halo/app/controller/content/ContentArchiveController.java
+++ b/src/main/java/run/halo/app/controller/content/ContentArchiveController.java
@@ -163,15 +163,15 @@ public class ContentArchiveController {
 
         List<Category> categories = postCategoryService.listCategoriesBy(post.getId());
         List<Tag> tags = postTagService.listTagsBy(post.getId());
-        List<PostMeta> postMetas = postMetaService.listPostMetasBy(post.getId());
+        List<PostMeta> metas = postMetaService.listPostMetasBy(post.getId());
 
         Page<BaseCommentVO> comments = postCommentService.pageVosBy(post.getId(), PageRequest.of(cp, optionService.getCommentPageSize(), sort));
 
         model.addAttribute("is_post", true);
         model.addAttribute("post", postService.convertToDetailVo(post));
         model.addAttribute("categories", categories);
-        model.addAttribute("postMetas", postMetas);
         model.addAttribute("tags", tags);
+        model.addAttribute("metas", postMetaService.convertToMap(metas));
         model.addAttribute("comments", comments);
 
         if (preview) {
diff --git a/src/main/java/run/halo/app/service/PostMetaService.java b/src/main/java/run/halo/app/service/PostMetaService.java
index 14632514d..c66607db0 100644
--- a/src/main/java/run/halo/app/service/PostMetaService.java
+++ b/src/main/java/run/halo/app/service/PostMetaService.java
@@ -1,7 +1,6 @@
 package run.halo.app.service;
 
 import org.springframework.lang.NonNull;
-import org.springframework.lang.Nullable;
 import run.halo.app.model.dto.PostMetaDTO;
 import run.halo.app.model.entity.PostMeta;
 import run.halo.app.service.base.BaseMetaService;
@@ -19,17 +18,55 @@ import java.util.Set;
  * @date 2019-08-04
  */
 public interface PostMetaService extends BaseMetaService<PostMeta> {
-    List<PostMeta> createOrUpdateByPostId(Integer id, Set<PostMeta> postMetas);
 
-    List<PostMeta> listPostMetasBy(Integer id);
+    /**
+     * Creates by post metas and post id.
+     *
+     * @param postId    post id must not be null
+     * @param postMetas post metas must not be null
+     * @return a list of post meta
+     */
+    List<PostMeta> createOrUpdateByPostId(@NonNull Integer postId, @NonNull Set<PostMeta> postMetas);
 
-    List<PostMeta> removeByPostId(Integer postId);
+    /**
+     * Lists post metas by post id.
+     *
+     * @param postId post id must not be null
+     * @return a list of post meta
+     */
+    List<PostMeta> listPostMetasBy(@NonNull Integer postId);
 
-    Map<Integer, List<PostMeta>> listPostMetaListMap(Set<Integer> postIds);
+    /**
+     * Remove post metas by post id.
+     *
+     * @param postId post id must not be null
+     * @return a list of post meta
+     */
+    List<PostMeta> removeByPostId(@NonNull Integer postId);
 
+    /**
+     * Lists post metas as map.
+     *
+     * @param postIds post ids must not be null
+     * @return a map of post meta
+     */
+    Map<Integer, List<PostMeta>> listPostMetaAsMap(@NonNull Set<Integer> postIds);
+
+    /**
+     * Convert PostMeta to PostMetaDTO.
+     *
+     * @param postMeta post meta must not be null
+     * @return post meta vo
+     */
     @NonNull
     PostMetaDTO convertTo(@NonNull PostMeta postMeta);
 
+    /**
+     * Convert list of PostMeta to list of PostMetaDTO.
+     *
+     * @param postMetaList post meta list must not be null
+     * @return a list of post meta dto
+     */
     @NonNull
-    List<PostMetaDTO> convertTo(@Nullable List<PostMeta> postMetaList);
+    List<PostMetaDTO> convertTo(@NonNull List<PostMeta> postMetaList);
 }
diff --git a/src/main/java/run/halo/app/service/impl/PostMetaServiceImpl.java b/src/main/java/run/halo/app/service/impl/PostMetaServiceImpl.java
index 8b6d41cf9..7480f2c1b 100644
--- a/src/main/java/run/halo/app/service/impl/PostMetaServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/PostMetaServiceImpl.java
@@ -47,6 +47,7 @@ public class PostMetaServiceImpl extends BaseMetaServiceImpl<PostMeta> implement
     @Override
     public List<PostMeta> createOrUpdateByPostId(Integer postId, Set<PostMeta> postMetas) {
         Assert.notNull(postId, "Post id must not be null");
+        Assert.notNull(postMetas, "Post metas must not be null");
         if (CollectionUtils.isEmpty(postMetas)) {
             return Collections.emptyList();
         }
@@ -75,7 +76,8 @@ public class PostMetaServiceImpl extends BaseMetaServiceImpl<PostMeta> implement
     }
 
     @Override
-    public Map<Integer, List<PostMeta>> listPostMetaListMap(Set<Integer> postIds) {
+    public Map<Integer, List<PostMeta>> listPostMetaAsMap(Set<Integer> postIds) {
+        Assert.notNull(postIds, "Post ids must not be null");
         if (CollectionUtils.isEmpty(postIds)) {
             return Collections.emptyMap();
         }
diff --git a/src/main/java/run/halo/app/service/impl/PostServiceImpl.java b/src/main/java/run/halo/app/service/impl/PostServiceImpl.java
index 0ef975127..fdbb1bac9 100644
--- a/src/main/java/run/halo/app/service/impl/PostServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/PostServiceImpl.java
@@ -428,7 +428,7 @@ public class PostServiceImpl extends BasePostServiceImpl<Post> implements PostSe
         Map<Integer, Long> commentCountMap = postCommentService.countByPostIds(postIds);
 
         // Get post meta list map
-        Map<Integer, List<PostMeta>> postMetaListMap = postMetaService.listPostMetaListMap(postIds);
+        Map<Integer, List<PostMeta>> postMetaListMap = postMetaService.listPostMetaAsMap(postIds);
 
         return postPage.map(post -> {
             PostListVO postListVO = new PostListVO().convertFrom(post);