feat: use joda time for cursor process

src/main/java/io/spring/application/ArticleQueryService.java

@@ -16,6 +16,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import org.joda.time.DateTime;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
@@ -60,7 +61,11 @@ public class ArticleQueryService {
   }
 
   public CursorPager<ArticleData> findRecentArticlesWithCursor(
-      String tag, String author, String favoritedBy, CursorPageParameter page, User currentUser) {
+      String tag,
+      String author,
+      String favoritedBy,
+      CursorPageParameter<DateTime> page,
+      User currentUser) {
     List<String> articleIds =
         articleReadService.findArticlesWithCursor(tag, author, favoritedBy, page);
     if (articleIds.size() == 0) {
@@ -81,7 +86,8 @@ public class ArticleQueryService {
     }
   }
 
-  public CursorPager<ArticleData> findUserFeedWithCursor(User user, CursorPageParameter page) {
+  public CursorPager<ArticleData> findUserFeedWithCursor(
+      User user, CursorPageParameter<DateTime> page) {
     List<String> followdUsers = userRelationshipQueryService.followedUsers(user.getId());
     if (followdUsers.size() == 0) {
       return new CursorPager<>(new ArrayList<>(), page.getDirection(), false);

src/main/java/io/spring/application/CommentQueryService.java

@@ -10,6 +10,7 @@ import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
+import org.joda.time.DateTime;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -58,7 +59,7 @@ public class CommentQueryService {
   }
 
   public CursorPager<CommentData> findByArticleIdWithCursor(
-      String articleId, User user, CursorPageParameter page) {
+      String articleId, User user, CursorPageParameter<DateTime> page) {
     List<CommentData> comments = commentReadService.findByArticleIdWithCursor(articleId, page);
     if (comments.isEmpty()) {
       return new CursorPager<>(new ArrayList<>(), page.getDirection(), false);

src/main/java/io/spring/application/CursorPageParameter.java

@@ -6,13 +6,13 @@ import lombok.NoArgsConstructor;
 
 @Data
 @NoArgsConstructor
-public class CursorPageParameter {
+public class CursorPageParameter<T> {
   private static final int MAX_LIMIT = 1000;
   private int limit = 20;
-  private String cursor;
+  private T cursor;
   private Direction direction;
 
-  public CursorPageParameter(String cursor, int limit, Direction direction) {
+  public CursorPageParameter(T cursor, int limit, Direction direction) {
     setLimit(limit);
     setCursor(cursor);
     setDirection(direction);
@@ -26,13 +26,9 @@ public class CursorPageParameter {
     return limit + 1;
   }
 
-  private void setCursor(String cursor) {
+  private void setCursor(T cursor) {
-    if (cursor == null) {
-      this.cursor = "";
-    } else {
     this.cursor = cursor;
   }
-  }
 
   private void setLimit(int limit) {
     if (limit > MAX_LIMIT) {

src/main/java/io/spring/application/CursorPager.java

@@ -29,12 +29,12 @@ public class CursorPager<T extends Node> {
     return previous;
   }
 
-  public String getStartCursor() {
+  public PageCursor getStartCursor() {
-    return data.isEmpty() ? "" : data.get(0).getCursor();
+    return data.isEmpty() ? null : data.get(0).getCursor();
   }
 
-  public String getEndCursor() {
+  public PageCursor getEndCursor() {
-    return data.isEmpty() ? "" : data.get(data.size() - 1).getCursor();
+    return data.isEmpty() ? null : data.get(data.size() - 1).getCursor();
   }
 
   public enum Direction {

src/main/java/io/spring/application/DateTimeCursor.java

@@ -0,0 +1,23 @@
+package io.spring.application;
+
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
+
+public class DateTimeCursor extends PageCursor<DateTime> {
+
+  public DateTimeCursor(DateTime data) {
+    super(data);
+  }
+
+  @Override
+  public String toString() {
+    return String.valueOf(getData().getMillis());
+  }
+
+  public static DateTime parse(String cursor) {
+    if (cursor == null) {
+      return null;
+    }
+    return new DateTime().withMillis(Long.parseLong(cursor)).withZone(DateTimeZone.UTC);
+  }
+}

src/main/java/io/spring/application/Node.java

@@ -1,5 +1,5 @@
 package io.spring.application;
 
 public interface Node {
-  String getCursor();
+  PageCursor getCursor();
 }

src/main/java/io/spring/application/PageCursor.java

@@ -0,0 +1,18 @@
+package io.spring.application;
+
+public abstract class PageCursor<T> {
+  private T data;
+
+  public PageCursor(T data) {
+    this.data = data;
+  }
+
+  public T getData() {
+    return data;
+  }
+
+  @Override
+  public String toString() {
+    return data.toString();
+  }
+}

src/main/java/io/spring/application/data/ArticleData.java

@@ -1,6 +1,7 @@
 package io.spring.application.data;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import io.spring.application.DateTimeCursor;
 import java.util.List;
 import lombok.AllArgsConstructor;
 import lombok.Data;
@@ -26,7 +27,7 @@ public class ArticleData implements io.spring.application.Node {
   private ProfileData profileData;
 
   @Override
-  public String getCursor() {
+  public DateTimeCursor getCursor() {
-    return String.valueOf(getUpdatedAt().getMillis());
+    return new DateTimeCursor(updatedAt);
   }
 }

src/main/java/io/spring/application/data/CommentData.java

@@ -2,6 +2,7 @@ package io.spring.application.data;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import io.spring.application.DateTimeCursor;
 import io.spring.application.Node;
 import lombok.AllArgsConstructor;
 import lombok.Data;
@@ -22,7 +23,7 @@ public class CommentData implements Node {
   private ProfileData profileData;
 
   @Override
-  public String getCursor() {
+  public DateTimeCursor getCursor() {
-    return String.valueOf(createdAt.getMillis());
+    return new DateTimeCursor(createdAt);
   }
 }

src/main/java/io/spring/graphql/users/ArticleDatafetcher.java

@@ -8,12 +8,12 @@ import graphql.execution.DataFetcherResult;
 import graphql.relay.DefaultConnectionCursor;
 import graphql.relay.DefaultPageInfo;
 import graphql.schema.DataFetchingEnvironment;
-import io.spring.Util;
 import io.spring.api.exception.ResourceNotFoundException;
 import io.spring.application.ArticleQueryService;
 import io.spring.application.CursorPageParameter;
 import io.spring.application.CursorPager;
 import io.spring.application.CursorPager.Direction;
+import io.spring.application.DateTimeCursor;
 import io.spring.application.data.ArticleData;
 import io.spring.application.data.CommentData;
 import io.spring.core.user.User;
@@ -62,11 +62,13 @@ public class ArticleDatafetcher {
     if (first != null) {
       articles =
           articleQueryService.findUserFeedWithCursor(
-              current, new CursorPageParameter(after, first, Direction.NEXT));
+              current,
+              new CursorPageParameter<>(DateTimeCursor.parse(after), first, Direction.NEXT));
     } else {
       articles =
           articleQueryService.findUserFeedWithCursor(
-              current, new CursorPageParameter(before, last, Direction.PREV));
+              current,
+              new CursorPageParameter<>(DateTimeCursor.parse(before), last, Direction.PREV));
     }
     graphql.relay.PageInfo pageInfo = buildArticlePageInfo(articles);
     ArticlesConnection articlesConnection =
@@ -77,7 +79,7 @@ public class ArticleDatafetcher {
                     .map(
                         a ->
                             ArticleEdge.newBuilder()
-                                .cursor(a.getCursor())
+                                .cursor(a.getCursor().toString())
                                 .node(buildArticleResult(a))
                                 .build())
                     .collect(Collectors.toList()))
@@ -110,11 +112,13 @@ public class ArticleDatafetcher {
     if (first != null) {
       articles =
           articleQueryService.findUserFeedWithCursor(
-              target, new CursorPageParameter(after, first, Direction.NEXT));
+              target,
+              new CursorPageParameter<>(DateTimeCursor.parse(after), first, Direction.NEXT));
     } else {
       articles =
           articleQueryService.findUserFeedWithCursor(
-              target, new CursorPageParameter(before, last, Direction.PREV));
+              target,
+              new CursorPageParameter<>(DateTimeCursor.parse(before), last, Direction.PREV));
     }
     graphql.relay.PageInfo pageInfo = buildArticlePageInfo(articles);
     ArticlesConnection articlesConnection =
@@ -125,7 +129,7 @@ public class ArticleDatafetcher {
                     .map(
                         a ->
                             ArticleEdge.newBuilder()
-                                .cursor(a.getCursor())
+                                .cursor(a.getCursor().toString())
                                 .node(buildArticleResult(a))
                                 .build())
                     .collect(Collectors.toList()))
@@ -158,7 +162,7 @@ public class ArticleDatafetcher {
               null,
               null,
               profile.getUsername(),
-              new CursorPageParameter(after, first, Direction.NEXT),
+              new CursorPageParameter<>(DateTimeCursor.parse(after), first, Direction.NEXT),
               current);
     } else {
       articles =
@@ -166,7 +170,7 @@ public class ArticleDatafetcher {
               null,
               null,
               profile.getUsername(),
-              new CursorPageParameter(before, last, Direction.PREV),
+              new CursorPageParameter<>(DateTimeCursor.parse(before), last, Direction.PREV),
               current);
     }
     graphql.relay.PageInfo pageInfo = buildArticlePageInfo(articles);
@@ -179,7 +183,7 @@ public class ArticleDatafetcher {
                     .map(
                         a ->
                             ArticleEdge.newBuilder()
-                                .cursor(a.getCursor())
+                                .cursor(a.getCursor().toString())
                                 .node(buildArticleResult(a))
                                 .build())
                     .collect(Collectors.toList()))
@@ -212,7 +216,7 @@ public class ArticleDatafetcher {
               null,
               profile.getUsername(),
               null,
-              new CursorPageParameter(after, first, Direction.NEXT),
+              new CursorPageParameter<>(DateTimeCursor.parse(after), first, Direction.NEXT),
               current);
     } else {
       articles =
@@ -220,7 +224,7 @@ public class ArticleDatafetcher {
               null,
               profile.getUsername(),
               null,
-              new CursorPageParameter(before, last, Direction.PREV),
+              new CursorPageParameter<>(DateTimeCursor.parse(before), last, Direction.PREV),
               current);
     }
     graphql.relay.PageInfo pageInfo = buildArticlePageInfo(articles);
@@ -232,7 +236,7 @@ public class ArticleDatafetcher {
                     .map(
                         a ->
                             ArticleEdge.newBuilder()
-                                .cursor(a.getCursor())
+                                .cursor(a.getCursor().toString())
                                 .node(buildArticleResult(a))
                                 .build())
                     .collect(Collectors.toList()))
@@ -267,7 +271,7 @@ public class ArticleDatafetcher {
               withTag,
               authoredBy,
               favoritedBy,
-              new CursorPageParameter(after, first, Direction.NEXT),
+              new CursorPageParameter<>(DateTimeCursor.parse(after), first, Direction.NEXT),
               current);
     } else {
       articles =
@@ -275,7 +279,7 @@ public class ArticleDatafetcher {
               withTag,
               authoredBy,
               favoritedBy,
-              new CursorPageParameter(before, last, Direction.PREV),
+              new CursorPageParameter<>(DateTimeCursor.parse(before), last, Direction.PREV),
               current);
     }
     graphql.relay.PageInfo pageInfo = buildArticlePageInfo(articles);
@@ -287,7 +291,7 @@ public class ArticleDatafetcher {
                     .map(
                         a ->
                             ArticleEdge.newBuilder()
-                                .cursor(a.getCursor())
+                                .cursor(a.getCursor().toString())
                                 .node(buildArticleResult(a))
                                 .build())
                     .collect(Collectors.toList()))
@@ -360,12 +364,12 @@ public class ArticleDatafetcher {
 
   private DefaultPageInfo buildArticlePageInfo(CursorPager<ArticleData> articles) {
     return new DefaultPageInfo(
-        Util.isEmpty(articles.getStartCursor())
+        articles.getStartCursor() == null
             ? null
-            : new DefaultConnectionCursor(articles.getStartCursor()),
+            : new DefaultConnectionCursor(articles.getStartCursor().toString()),
-        Util.isEmpty(articles.getEndCursor())
+        articles.getEndCursor() == null
             ? null
-            : new DefaultConnectionCursor(articles.getEndCursor()),
+            : new DefaultConnectionCursor(articles.getEndCursor().toString()),
         articles.hasPrevious(),
         articles.hasNext());
   }

src/main/java/io/spring/graphql/users/CommentDatafetcher.java

@@ -7,11 +7,11 @@ import com.netflix.graphql.dgs.InputArgument;
 import graphql.execution.DataFetcherResult;
 import graphql.relay.DefaultConnectionCursor;
 import graphql.relay.DefaultPageInfo;
-import io.spring.Util;
 import io.spring.application.CommentQueryService;
 import io.spring.application.CursorPageParameter;
 import io.spring.application.CursorPager;
 import io.spring.application.CursorPager.Direction;
+import io.spring.application.DateTimeCursor;
 import io.spring.application.data.ArticleData;
 import io.spring.application.data.CommentData;
 import io.spring.core.user.User;
@@ -72,11 +72,15 @@ public class CommentDatafetcher {
     if (first != null) {
       comments =
           commentQueryService.findByArticleIdWithCursor(
-              articleData.getId(), current, new CursorPageParameter(after, first, Direction.NEXT));
+              articleData.getId(),
+              current,
+              new CursorPageParameter<>(DateTimeCursor.parse(after), first, Direction.NEXT));
     } else {
       comments =
           commentQueryService.findByArticleIdWithCursor(
-              articleData.getId(), current, new CursorPageParameter(before, last, Direction.PREV));
+              articleData.getId(),
+              current,
+              new CursorPageParameter<>(DateTimeCursor.parse(before), last, Direction.PREV));
     }
     graphql.relay.PageInfo pageInfo = buildCommentPageInfo(comments);
     CommentsConnection result =
@@ -87,7 +91,7 @@ public class CommentDatafetcher {
                     .map(
                         a ->
                             CommentEdge.newBuilder()
-                                .cursor(a.getCursor())
+                                .cursor(a.getCursor().toString())
                                 .node(buildCommentResult(a))
                                 .build())
                     .collect(Collectors.toList()))
@@ -101,12 +105,12 @@ public class CommentDatafetcher {
 
   private DefaultPageInfo buildCommentPageInfo(CursorPager<CommentData> comments) {
     return new DefaultPageInfo(
-        Util.isEmpty(comments.getStartCursor())
+        comments.getStartCursor() == null
             ? null
-            : new DefaultConnectionCursor(comments.getStartCursor()),
+            : new DefaultConnectionCursor(comments.getStartCursor().toString()),
-        Util.isEmpty(comments.getEndCursor())
+        comments.getEndCursor() == null
             ? null
-            : new DefaultConnectionCursor(comments.getEndCursor()),
+            : new DefaultConnectionCursor(comments.getEndCursor().toString()),
         comments.hasPrevious(),
         comments.hasNext());
   }

src/main/java/io/spring/infrastructure/mybatis/readservice/CommentReadService.java

@@ -5,6 +5,7 @@ import io.spring.application.data.CommentData;
 import java.util.List;
 import org.apache.ibatis.annotations.Mapper;
 import org.apache.ibatis.annotations.Param;
+import org.joda.time.DateTime;
 
 @Mapper
 public interface CommentReadService {
@@ -13,5 +14,5 @@ public interface CommentReadService {
   List<CommentData> findByArticleId(@Param("articleId") String articleId);
 
   List<CommentData> findByArticleIdWithCursor(
-      @Param("articleId") String articleId, @Param("page") CursorPageParameter page);
+      @Param("articleId") String articleId, @Param("page") CursorPageParameter<DateTime> page);
 }

src/main/resources/mapper/ArticleReadService.xml

@@ -116,10 +116,10 @@
             <if test="favoritedBy != null">
                 AND AFU.username = #{favoritedBy}
             </if>
-            <if test='page.cursor != "" and page.direction.name() == "NEXT"'>
+            <if test='page.cursor != null and page.direction.name() == "NEXT"'>
                 AND A.created_at &lt; #{page.cursor}
             </if>
-            <if test='page.cursor != "" and page.direction.name() == "PREV"'>
+            <if test='page.cursor != null and page.direction.name() == "PREV"'>
                 AND A.created_at > #{page.cursor}
             </if>
         </where>
@@ -138,10 +138,10 @@
         <foreach index="index" collection="authors" item="id" open="(" separator="," close=")">
             #{id}
         </foreach>
-        <if test='page.cursor != "" and page.direction.name() == "NEXT"'>
+        <if test='page.cursor != null and page.direction.name() == "NEXT"'>
             AND A.created_at &lt; #{page.cursor}
         </if>
-        <if test='page.cursor != "" and page.direction.name() == "PREV"'>
+        <if test='page.cursor != null and page.direction.name() == "PREV"'>
             AND A.created_at > #{page.cursor}
         </if>
         <if test='page.direction.name() == "NEXT"'>

src/main/resources/mapper/CommentReadService.xml

@@ -25,10 +25,10 @@
         <include refid="selectCommentData"/>
         <where>
         C.article_id = #{articleId}
-        <if test='page.cursor != "" and page.direction.name() == "NEXT"'>
+        <if test='page.cursor != null and page.direction.name() == "NEXT"'>
             AND C.created_at &lt; #{page.cursor}
         </if>
-        <if test='page.cursor != "" and page.direction.name() == "PREV"'>
+        <if test='page.cursor != null and page.direction.name() == "PREV"'>
             AND C.created_at > #{page.cursor}
         </if>
         </where>

src/test/java/io/spring/application/article/ArticleQueryServiceTest.java

@@ -9,6 +9,7 @@ import io.spring.application.ArticleQueryService;
 import io.spring.application.CursorPageParameter;
 import io.spring.application.CursorPager;
 import io.spring.application.CursorPager.Direction;
+import io.spring.application.DateTimeCursor;
 import io.spring.application.Page;
 import io.spring.application.data.ArticleData;
 import io.spring.application.data.ArticleDataList;
@@ -124,7 +125,7 @@ public class ArticleQueryServiceTest extends DbTestBase {
 
     CursorPager<ArticleData> recentArticles =
         queryService.findRecentArticlesWithCursor(
-            null, null, null, new CursorPageParameter("", 20, Direction.NEXT), user);
+            null, null, null, new CursorPageParameter<>(null, 20, Direction.NEXT), user);
     assertEquals(recentArticles.getData().size(), 2);
     assertEquals(recentArticles.getData().get(0).getId(), article.getId());
 
@@ -133,14 +134,15 @@ public class ArticleQueryServiceTest extends DbTestBase {
             null,
             null,
             null,
-            new CursorPageParameter(recentArticles.getEndCursor(), 20, Direction.NEXT),
+            new CursorPageParameter<DateTime>(
+                DateTimeCursor.parse(recentArticles.getEndCursor().toString()), 20, Direction.NEXT),
             user);
     assertEquals(nodata.getData().size(), 0);
-    assertEquals(nodata.getStartCursor(), "");
+    assertEquals(nodata.getStartCursor(), null);
 
     CursorPager<ArticleData> prevArticles =
         queryService.findRecentArticlesWithCursor(
-            null, null, null, new CursorPageParameter("", 20, Direction.PREV), user);
+            null, null, null, new CursorPageParameter<>(null, 20, Direction.PREV), user);
     assertEquals(prevArticles.getData().size(), 2);
   }