DJ-73: Migrate backend off Joda-Time to java.time + relative frontend timestamps

build.gradle

@@ -66,7 +66,6 @@ dependencies {
     implementation 'io.jsonwebtoken:jjwt-api:0.11.2'
     runtimeOnly 'io.jsonwebtoken:jjwt-impl:0.11.2',
                 'io.jsonwebtoken:jjwt-jackson:0.11.2'
-    implementation 'joda-time:joda-time:2.10.13'
     implementation 'org.xerial:sqlite-jdbc:3.36.0.3'
 
     compileOnly 'org.projectlombok:lombok'

frontend/components/article/ArticleMeta.tsx

@@ -3,6 +3,7 @@ import React from "react";
 import ArticleActions from "./ArticleActions";
 import CustomImage from "../common/CustomImage";
 import CustomLink from "../common/CustomLink";
+import relativeTime from "../../lib/utils/relativeTime";
 
 const ArticleMeta = ({ article }) => {
   if (!article) return;
@@ -24,8 +25,11 @@ const ArticleMeta = ({ article }) => {
         >
           {article.author?.username}
         </CustomLink>
-        <span className="date">
-          {new Date(article.createdAt).toDateString()}
+        <span
+          className="date"
+          title={new Date(article.createdAt).toLocaleString()}
+        >
+          {relativeTime(article.createdAt)}
         </span>
       </div>
 

frontend/components/article/ArticlePreview.tsx

@@ -9,6 +9,7 @@ import CustomImage from "../common/CustomImage";
 import { usePageDispatch } from "../../lib/context/PageContext";
 import checkLogin from "../../lib/utils/checkLogin";
 import { SERVER_BASE_URL } from "../../lib/utils/constant";
+import relativeTime from "../../lib/utils/relativeTime";
 import storage from "../../lib/utils/storage";
 
 const FAVORITED_CLASS = "btn btn-sm btn-primary";
@@ -90,8 +91,11 @@ const ArticlePreview = ({ article }) => {
           >
             <span onClick={() => setPage(0)}>{preview.author.username}</span>
           </CustomLink>
-          <span className="date">
-            {new Date(preview.createdAt).toDateString()}
+          <span
+            className="date"
+            title={new Date(preview.createdAt).toLocaleString()}
+          >
+            {relativeTime(preview.createdAt)}
           </span>
         </div>
 

frontend/components/comment/Comment.tsx

@@ -6,6 +6,7 @@ import CustomImage from "../common/CustomImage";
 import Maybe from "../common/Maybe";
 import DeleteButton from "./DeleteButton";
 import checkLogin from "../../lib/utils/checkLogin";
+import relativeTime from "../../lib/utils/relativeTime";
 import storage from "../../lib/utils/storage";
 
 const Comment = ({ comment }) => {
@@ -39,8 +40,11 @@ const Comment = ({ comment }) => {
         >
           {comment.author.username}
         </CustomLink>
-        <span className="date-posted">
-          {new Date(comment.createdAt).toDateString()}
+        <span
+          className="date-posted"
+          title={new Date(comment.createdAt).toLocaleString()}
+        >
+          {relativeTime(comment.createdAt)}
         </span>
         <Maybe test={canModify}>
           <DeleteButton commentId={comment.id} />

frontend/lib/utils/relativeTime.ts

@@ -0,0 +1,29 @@
+const units = [
+  { name: "year", seconds: 31536000 },
+  { name: "month", seconds: 2592000 },
+  { name: "week", seconds: 604800 },
+  { name: "day", seconds: 86400 },
+  { name: "hour", seconds: 3600 },
+  { name: "minute", seconds: 60 },
+  { name: "second", seconds: 1 },
+];
+
+export default function relativeTime(value: string): string {
+  const date = new Date(value);
+
+  if (Number.isNaN(date.getTime())) return "";
+
+  const difference = date.getTime() - Date.now();
+  const seconds = Math.abs(difference) / 1000;
+
+  if (seconds < 45) return "just now";
+
+  const unit = units.find(({ seconds: unitSeconds }) => seconds >= unitSeconds);
+  const amount = Math.round(difference / 1000 / unit.seconds);
+
+  const formatter = new (Intl as any).RelativeTimeFormat("en", {
+    numeric: "always",
+  });
+
+  return formatter.format(amount, unit.name);
+}

src/main/java/io/spring/JacksonCustomizations.java

@@ -6,13 +6,16 @@
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.fasterxml.jackson.databind.ser.std.StdSerializer;
 import java.io.IOException;
-import org.joda.time.DateTime;
-import org.joda.time.format.ISODateTimeFormat;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
 @Configuration
 public class JacksonCustomizations {
+  private static final DateTimeFormatter DATE_TIME_FORMATTER =
+      DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'").withZone(ZoneOffset.UTC);
 
   @Bean
   public Module realWorldModules() {
@@ -21,23 +24,23 @@ public Module realWorldModules() {
 
   public static class RealWorldModules extends SimpleModule {
     public RealWorldModules() {
-      addSerializer(DateTime.class, new DateTimeSerializer());
+      addSerializer(Instant.class, new InstantSerializer());
     }
   }
 
-  public static class DateTimeSerializer extends StdSerializer<DateTime> {
+  public static class InstantSerializer extends StdSerializer<Instant> {
 
-    protected DateTimeSerializer() {
-      super(DateTime.class);
+    protected InstantSerializer() {
+      super(Instant.class);
     }
 
     @Override
-    public void serialize(DateTime value, JsonGenerator gen, SerializerProvider provider)
+    public void serialize(Instant value, JsonGenerator gen, SerializerProvider provider)
         throws IOException {
       if (value == null) {
         gen.writeNull();
       } else {
-        gen.writeString(ISODateTimeFormat.dateTime().withZoneUTC().print(value));
+        gen.writeString(DATE_TIME_FORMATTER.format(value));
       }
     }
   }

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

@@ -9,6 +9,7 @@
 import io.spring.infrastructure.mybatis.readservice.ArticleFavoritesReadService;
 import io.spring.infrastructure.mybatis.readservice.ArticleReadService;
 import io.spring.infrastructure.mybatis.readservice.UserRelationshipQueryService;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -17,7 +18,6 @@
 import java.util.Optional;
 import java.util.Set;
 import lombok.AllArgsConstructor;
-import org.joda.time.DateTime;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -55,7 +55,7 @@ public CursorPager<ArticleData> findRecentArticlesWithCursor(
       String tag,
       String author,
       String favoritedBy,
-      CursorPageParameter<DateTime> page,
+      CursorPageParameter<Instant> page,
       User currentUser) {
     List<String> articleIds =
         articleReadService.findArticlesWithCursor(tag, author, favoritedBy, page);
@@ -78,7 +78,7 @@ public CursorPager<ArticleData> findRecentArticlesWithCursor(
   }
 
   public CursorPager<ArticleData> findUserFeedWithCursor(
-      User user, CursorPageParameter<DateTime> page) {
+      User user, CursorPageParameter<Instant> 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

@@ -4,14 +4,14 @@
 import io.spring.core.user.User;
 import io.spring.infrastructure.mybatis.readservice.CommentReadService;
 import io.spring.infrastructure.mybatis.readservice.UserRelationshipQueryService;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import lombok.AllArgsConstructor;
-import org.joda.time.DateTime;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -54,7 +54,7 @@ public List<CommentData> findByArticleId(String articleId, User user) {
   }
 
   public CursorPager<CommentData> findByArticleIdWithCursor(
-      String articleId, User user, CursorPageParameter<DateTime> page) {
+      String articleId, User user, CursorPageParameter<Instant> 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/DateTimeCursor.java

@@ -1,23 +1,22 @@
 package io.spring.application;
 
-import org.joda.time.DateTime;
-import org.joda.time.DateTimeZone;
+import java.time.Instant;
 
-public class DateTimeCursor extends PageCursor<DateTime> {
+public class DateTimeCursor extends PageCursor<Instant> {
 
-  public DateTimeCursor(DateTime data) {
+  public DateTimeCursor(Instant data) {
     super(data);
   }
 
   @Override
   public String toString() {
-    return String.valueOf(getData().getMillis());
+    return String.valueOf(getData().toEpochMilli());
   }
 
-  public static DateTime parse(String cursor) {
+  public static Instant parse(String cursor) {
     if (cursor == null) {
       return null;
     }
-    return new DateTime().withMillis(Long.parseLong(cursor)).withZone(DateTimeZone.UTC);
+    return Instant.ofEpochMilli(Long.parseLong(cursor));
   }
 }

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

@@ -2,11 +2,11 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import io.spring.application.DateTimeCursor;
+import java.time.Instant;
 import java.util.List;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
-import org.joda.time.DateTime;
 
 @Data
 @NoArgsConstructor
@@ -19,8 +19,8 @@ public class ArticleData implements io.spring.application.Node {
   private String body;
   private boolean favorited;
   private int favoritesCount;
-  private DateTime createdAt;
-  private DateTime updatedAt;
+  private Instant createdAt;
+  private Instant updatedAt;
   private List<String> tagList;
 
   @JsonProperty("author")

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

@@ -4,10 +4,10 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import io.spring.application.DateTimeCursor;
 import io.spring.application.Node;
+import java.time.Instant;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
-import org.joda.time.DateTime;
 
 @Data
 @NoArgsConstructor
@@ -16,8 +16,8 @@ public class CommentData implements Node {
   private String id;
   private String body;
   @JsonIgnore private String articleId;
-  private DateTime createdAt;
-  private DateTime updatedAt;
+  private Instant createdAt;
+  private Instant updatedAt;
 
   @JsonProperty("author")
   private ProfileData profileData;

src/main/java/io/spring/core/article/Article.java

@@ -3,13 +3,14 @@
 import static java.util.stream.Collectors.toList;
 
 import io.spring.Util;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.HashSet;
 import java.util.List;
 import java.util.UUID;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
-import org.joda.time.DateTime;
 
 @Getter
 @NoArgsConstructor
@@ -22,12 +23,12 @@ public class Article {
   private String description;
   private String body;
   private List<Tag> tags;
-  private DateTime createdAt;
-  private DateTime updatedAt;
+  private Instant createdAt;
+  private Instant updatedAt;
 
   public Article(
       String title, String description, String body, List<String> tagList, String userId) {
-    this(title, description, body, tagList, userId, new DateTime());
+    this(title, description, body, tagList, userId, Instant.now().truncatedTo(ChronoUnit.MILLIS));
   }
 
   public Article(
@@ -36,7 +37,7 @@ public Article(
       String body,
       List<String> tagList,
       String userId,
-      DateTime createdAt) {
+      Instant createdAt) {
     this.id = UUID.randomUUID().toString();
     this.slug = toSlug(title);
     this.title = title;
@@ -52,15 +53,15 @@ public void update(String title, String description, String body) {
     if (!Util.isEmpty(title)) {
       this.title = title;
       this.slug = toSlug(title);
-      this.updatedAt = new DateTime();
+      this.updatedAt = Instant.now().truncatedTo(ChronoUnit.MILLIS);
     }
     if (!Util.isEmpty(description)) {
       this.description = description;
-      this.updatedAt = new DateTime();
+      this.updatedAt = Instant.now().truncatedTo(ChronoUnit.MILLIS);
     }
     if (!Util.isEmpty(body)) {
       this.body = body;
-      this.updatedAt = new DateTime();
+      this.updatedAt = Instant.now().truncatedTo(ChronoUnit.MILLIS);
     }
   }
 

src/main/java/io/spring/core/comment/Comment.java

@@ -1,10 +1,11 @@
 package io.spring.core.comment;
 
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.UUID;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
-import org.joda.time.DateTime;
 
 @Getter
 @NoArgsConstructor
@@ -14,13 +15,13 @@ public class Comment {
   private String body;
   private String userId;
   private String articleId;
-  private DateTime createdAt;
+  private Instant createdAt;
 
   public Comment(String body, String userId, String articleId) {
     this.id = UUID.randomUUID().toString();
     this.body = body;
     this.userId = userId;
     this.articleId = articleId;
-    this.createdAt = new DateTime();
+    this.createdAt = Instant.now().truncatedTo(ChronoUnit.MILLIS);
   }
 }