Try to add topic pages

src/main/java/site/easystartup/easystartupcore/config/AppConfig.java

@@ -11,7 +11,6 @@ import org.springframework.security.crypto.password.PasswordEncoder;
 @ComponentScan(basePackages = {"site.easystartup.easystartupcore"})
 public class AppConfig {
 
-
     @Bean
     public PasswordEncoder passwordEncoder() {
         return new BCryptPasswordEncoder();

src/main/java/site/easystartup/easystartupcore/forum/controller/ForumController.java

@@ -8,33 +8,75 @@ import org.springframework.security.core.userdetails.User;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
 import org.springframework.web.bind.annotation.GetMapping;
-import site.easystartup.easystartupcore.forum.filter.FilterService;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import site.easystartup.easystartupcore.forum.domain.Topic;
+import site.easystartup.easystartupcore.forum.filter.ForumFilterService;
 import site.easystartup.easystartupcore.forum.repo.TopicRepo;
 
+import java.util.Date;
+
 @Controller
 @RequiredArgsConstructor(onConstructor_ = @Autowired)
 public class ForumController {
     private final TopicRepo topicRepo;
 
-    private final FilterService filterService;
+    private final ForumFilterService forumFilterService;
 
     @GetMapping("/forum")
     public String forumMain(Model model) {
         val topic = topicRepo.findAll();
         model.addAttribute("topics", topic);
-        return "forum";
+        return "/forum";
     }
 
     @GetMapping("/forum/my")
     public String forumMy(Model model) {
         User user = (User) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
-        val discussions = filterService.getDiscussionsByAuthor(user.getUsername());
+        val discussions = forumFilterService.getDiscussionsByAuthor(user.getUsername());
         model.addAttribute("discussions", discussions);
-        return "my-discussions";
+        return "/my-discussions";
     }
 
     @GetMapping("/forum/new")
     public String forumNew() {
         return "topic-new";
     }
+
+    @PostMapping("/forum/new")
+    public String forumNewTopic(@RequestParam String title,
+                               @RequestParam String description) {
+        description = description == null ? "" : description;
+        User user = (User) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
+        Topic topic = new Topic();
+        topic.setTitle(title);
+        topic.setDescription(description);
+        topic.setAuthor(user.getUsername());
+        topic.setLast_update(new Date());
+        topic.setSize(0);
+        topicRepo.save(topic);
+        return "/forum";
+    }
+
+    @GetMapping("/forum/{topic_id}")
+    public String topicFirstPage(@PathVariable(value = "topic_id") long topic_id,
+                              Model model) {
+        val pinned_discussions = forumFilterService.getPinnedDiscussionsByTopicId(topic_id);
+        model.addAttribute("pinned_discussions", pinned_discussions);
+        val discussions = forumFilterService.getSortedDiscussionsByTopicId(topic_id).subList(0, 15);
+        model.addAttribute("discussions", discussions);
+        return "topic-first";
+    }
+
+    @GetMapping("/forum/{topic_id}/page/{page_index}")
+    public String topicPage(@PathVariable(value = "topic_id") long topic_id,
+                            @PathVariable(value = "topic_id") long page_index,
+                              Model model) {
+        val pinned_discussions = forumFilterService.getPinnedDiscussionsByTopicId(topic_id);
+        model.addAttribute("pinned_discussions", pinned_discussions);
+        val discussions = forumFilterService.getSortedDiscussionsByTopicId(topic_id).subList(0, 15);
+        model.addAttribute("discussions", discussions);
+        return "topic-first";
+    }
 }

src/main/java/site/easystartup/easystartupcore/forum/domain/Discussion.java

@@ -13,7 +13,7 @@ import java.util.Objects;
 @ToString
 @RequiredArgsConstructor
 @Entity
-public class Discussion {
+public class Discussion implements Comparable<Discussion>{
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
     private long id;
@@ -21,6 +21,9 @@ public class Discussion {
     private String author;
     private Date date;
     private Date last_update;
+    private boolean pinned;
+    private DiscussionStatus status;
+    private long topic;
 
     @ElementCollection(targetClass = Long.class, fetch = FetchType.EAGER)
     @CollectionTable(name = "discussion_messages", joinColumns = @JoinColumn(name = "discussion_id"))
@@ -38,4 +41,11 @@ public class Discussion {
     public int hashCode() {
         return getClass().hashCode();
     }
+
+    @Override
+    public int compareTo(Discussion o) {
+        if (getLast_update() == null || o.getLast_update() == null)
+            return 0;
+        return getLast_update().compareTo(o.getLast_update());
+    }
 }

src/main/java/site/easystartup/easystartupcore/forum/filter/ForumFilterService.java

@@ -9,11 +9,12 @@ import site.easystartup.easystartupcore.forum.domain.DiscussionMessage;
 import site.easystartup.easystartupcore.forum.repo.DiscussionMessageRepo;
 import site.easystartup.easystartupcore.forum.repo.DiscussionRepo;
 
+import java.util.Collections;
 import java.util.List;
 
 @Component
 @RequiredArgsConstructor(onConstructor_ = @Autowired)
-public class FilterService {
+public class ForumFilterService {
     private final DiscussionMessageRepo discussionMessageRepo;
 
     private final DiscussionRepo discussionRepo;
@@ -33,4 +34,18 @@ public class FilterService {
                 .filter(d -> getMessagesByDiscussionId(d.getId()).stream()
                         .anyMatch(m -> m.getSender().equals(member))).toList();
     }
+
+    public List<Discussion> getPinnedDiscussionsByTopicId(long topic_id) {
+        return Lists.newArrayList(discussionRepo.findAll()).stream()
+                .filter(Discussion::isPinned)
+                .filter(d -> d.getTopic() == topic_id).toList();
+    }
+
+    public List<Discussion> getSortedDiscussionsByTopicId(long topic_id) {
+        List<Discussion> result = Lists.newArrayList(discussionRepo.findAll()).stream()
+                .filter(d -> !d.isPinned())
+                .filter(d -> d.getTopic() == topic_id).toList();
+        Collections.sort(result, Discussion::compareTo);
+        return result;
+    }
 }