Add category module and require post category

src/main/java/com/openisle/config/SecurityConfig.java

@@ -68,6 +68,9 @@ public class SecurityConfig {
                     .requestMatchers(HttpMethod.POST, "/api/auth/**").permitAll()
                     .requestMatchers(HttpMethod.GET, "/api/posts/**").permitAll()
                     .requestMatchers(HttpMethod.GET, "/api/comments/**").permitAll()
+                    .requestMatchers(HttpMethod.GET, "/api/categories/**").permitAll()
+                    .requestMatchers(HttpMethod.POST, "/api/categories/**").hasAuthority("ADMIN")
+                    .requestMatchers(HttpMethod.DELETE, "/api/categories/**").hasAuthority("ADMIN")
                     .requestMatchers("/api/admin/**").hasAuthority("ADMIN")
                     .anyRequest().authenticated()
             )
@@ -84,7 +87,7 @@ public class SecurityConfig {
                 String uri = request.getRequestURI();
 
                 boolean publicGet = "GET".equalsIgnoreCase(request.getMethod()) &&
-                        (uri.startsWith("/api/posts") || uri.startsWith("/api/comments"));
+                        (uri.startsWith("/api/posts") || uri.startsWith("/api/comments") || uri.startsWith("/api/categories"));
 
                 if (authHeader != null && authHeader.startsWith("Bearer ")) {
                     String token = authHeader.substring(7);

src/main/java/com/openisle/controller/CategoryController.java

@@ -0,0 +1,58 @@
+package com.openisle.controller;
+
+import com.openisle.model.Category;
+import com.openisle.service.CategoryService;
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@RestController
+@RequestMapping("/api/categories")
+@RequiredArgsConstructor
+public class CategoryController {
+    private final CategoryService categoryService;
+
+    @PostMapping
+    public CategoryDto create(@RequestBody CategoryRequest req) {
+        Category c = categoryService.createCategory(req.getName());
+        return toDto(c);
+    }
+
+    @DeleteMapping("/{id}")
+    public void delete(@PathVariable Long id) {
+        categoryService.deleteCategory(id);
+    }
+
+    @GetMapping
+    public List<CategoryDto> list() {
+        return categoryService.listCategories().stream()
+                .map(this::toDto)
+                .collect(Collectors.toList());
+    }
+
+    @GetMapping("/{id}")
+    public CategoryDto get(@PathVariable Long id) {
+        return toDto(categoryService.getCategory(id));
+    }
+
+    private CategoryDto toDto(Category c) {
+        CategoryDto dto = new CategoryDto();
+        dto.setId(c.getId());
+        dto.setName(c.getName());
+        return dto;
+    }
+
+    @Data
+    private static class CategoryRequest {
+        private String name;
+    }
+
+    @Data
+    private static class CategoryDto {
+        private Long id;
+        private String name;
+    }
+}

src/main/java/com/openisle/controller/PostController.java

@@ -39,7 +39,7 @@ public class PostController {
 
     @PostMapping
     public ResponseEntity<PostDto> createPost(@RequestBody PostRequest req, Authentication auth) {
-        Post post = postService.createPost(auth.getName(), req.getTitle(), req.getContent());
+        Post post = postService.createPost(auth.getName(), req.getCategoryId(), req.getTitle(), req.getContent());
         return ResponseEntity.ok(toDto(post));
     }
 
@@ -61,6 +61,7 @@ public class PostController {
         dto.setContent(post.getContent());
         dto.setCreatedAt(post.getCreatedAt());
         dto.setAuthor(post.getAuthor().getUsername());
+        dto.setCategory(post.getCategory().getName());
         dto.setViews(post.getViews());
 
         List<ReactionDto> reactions = reactionService.getReactionsForPost(post.getId())
@@ -119,6 +120,7 @@ public class PostController {
 
     @Data
     private static class PostRequest {
+        private Long categoryId;
         private String title;
         private String content;
     }
@@ -130,6 +132,7 @@ public class PostController {
         private String content;
         private LocalDateTime createdAt;
         private String author;
+        private String category;
         private long views;
         private List<CommentDto> comments;
         private List<ReactionDto> reactions;

src/main/java/com/openisle/model/Category.java

@@ -0,0 +1,20 @@
+package com.openisle.model;
+
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+@NoArgsConstructor
+@Table(name = "categories")
+public class Category {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(nullable = false, unique = true)
+    private String name;
+}

src/main/java/com/openisle/model/Post.java

@@ -30,6 +30,10 @@ public class Post {
     @JoinColumn(name = "author_id")
     private User author;
 
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "category_id")
+    private Category category;
+
     @Column(nullable = false)
     private long views = 0;
 

src/main/java/com/openisle/repository/CategoryRepository.java

@@ -0,0 +1,7 @@
+package com.openisle.repository;
+
+import com.openisle.model.Category;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface CategoryRepository extends JpaRepository<Category, Long> {
+}

src/main/java/com/openisle/service/CategoryService.java

@@ -0,0 +1,33 @@
+package com.openisle.service;
+
+import com.openisle.model.Category;
+import com.openisle.repository.CategoryRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class CategoryService {
+    private final CategoryRepository categoryRepository;
+
+    public Category createCategory(String name) {
+        Category category = new Category();
+        category.setName(name);
+        return categoryRepository.save(category);
+    }
+
+    public void deleteCategory(Long id) {
+        categoryRepository.deleteById(id);
+    }
+
+    public Category getCategory(Long id) {
+        return categoryRepository.findById(id)
+                .orElseThrow(() -> new IllegalArgumentException("Category not found"));
+    }
+
+    public List<Category> listCategories() {
+        return categoryRepository.findAll();
+    }
+}

src/main/java/com/openisle/service/PostService.java

@@ -2,8 +2,10 @@ package com.openisle.service;
 
 import com.openisle.model.Post;
 import com.openisle.model.User;
+import com.openisle.model.Category;
 import com.openisle.repository.PostRepository;
 import com.openisle.repository.UserRepository;
+import com.openisle.repository.CategoryRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
@@ -14,14 +16,18 @@ import java.util.List;
 public class PostService {
     private final PostRepository postRepository;
     private final UserRepository userRepository;
+    private final CategoryRepository categoryRepository;
 
-    public Post createPost(String username, String title, String content) {
+    public Post createPost(String username, Long categoryId, String title, String content) {
         User author = userRepository.findByUsername(username)
                 .orElseThrow(() -> new IllegalArgumentException("User not found"));
+        Category category = categoryRepository.findById(categoryId)
+                .orElseThrow(() -> new IllegalArgumentException("Category not found"));
         Post post = new Post();
         post.setTitle(title);
         post.setContent(content);
         post.setAuthor(author);
+        post.setCategory(category);
         return postRepository.save(post);
     }