Refactor category remove service

src/main/java/run/halo/app/service/CategoryService.java

@@ -1,10 +1,10 @@
 package run.halo.app.service;
 
-import run.halo.app.model.entity.Category;
-import run.halo.app.model.vo.CategoryVO;
-import run.halo.app.service.base.CrudService;
 import org.springframework.data.domain.Sort;
 import org.springframework.lang.NonNull;
+import org.springframework.transaction.annotation.Transactional;
+import run.halo.app.model.entity.Category;
+import run.halo.app.model.vo.CategoryVO;
 import run.halo.app.service.base.CrudService;
 
 import java.util.List;
@@ -40,4 +40,12 @@ public interface CategoryService extends CrudService<Category, Integer> {
      * @return Category
      */
     Category getBySlugName(@NonNull String slugName);
+
+    /**
+     * Removes category and post categories.
+     *
+     * @param categoryId category id must not be null
+     */
+    @Transactional
+    void removeCategoryAndPostCategoryBy(Integer categoryId);
 }

src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java

@@ -6,6 +6,7 @@ import run.halo.app.model.entity.Category;
 import run.halo.app.model.vo.CategoryVO;
 import run.halo.app.repository.CategoryRepository;
 import run.halo.app.service.CategoryService;
+import run.halo.app.service.PostCategoryService;
 import run.halo.app.service.base.AbstractCrudService;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.data.domain.Sort;
@@ -13,10 +14,6 @@ import org.springframework.lang.NonNull;
 import org.springframework.stereotype.Service;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
-import run.halo.app.exception.AlreadyExistsException;
-import run.halo.app.exception.NotFoundException;
-import run.halo.app.repository.CategoryRepository;
-import run.halo.app.service.base.AbstractCrudService;
 
 import java.util.Collections;
 import java.util.LinkedList;
@@ -34,9 +31,13 @@ public class CategoryServiceImpl extends AbstractCrudService<Category, Integer>
 
     private final CategoryRepository categoryRepository;
 
-    public CategoryServiceImpl(CategoryRepository categoryRepository) {
+    private final PostCategoryService postCategoryService;
+
+    public CategoryServiceImpl(CategoryRepository categoryRepository,
+                               PostCategoryService postCategoryService) {
         super(categoryRepository);
         this.categoryRepository = categoryRepository;
+        this.postCategoryService = postCategoryService;
     }
 
     /**
@@ -162,4 +163,12 @@ public class CategoryServiceImpl extends AbstractCrudService<Category, Integer>
     public Category getBySlugName(String slugName) {
         return categoryRepository.getBySlugName(slugName).orElseThrow(() -> new NotFoundException("The Category does not exist").setErrorData(slugName));
     }
+
+    @Override
+    public void removeCategoryAndPostCategoryBy(Integer categoryId) {
+        // Remove category
+        removeById(categoryId);
+        // Remove post categories
+        postCategoryService.removeByCategoryId(categoryId);
+    }
 }

src/main/java/run/halo/app/service/impl/PostServiceImpl.java

@@ -405,6 +405,7 @@ public class PostServiceImpl extends AbstractCrudService<Post, Integer> implemen
             postListVO.setCategories(Optional.ofNullable(categoryListMap.get(post.getId()))
                     .orElseGet(LinkedList::new)
                     .stream()
+                    .filter(Objects::nonNull)
                     .map(category -> new CategoryOutputDTO().<CategoryOutputDTO>convertFrom(category))
                     .collect(Collectors.toList()));
 

src/main/java/run/halo/app/utils/ValidationUtils.java

@@ -15,7 +15,7 @@ import java.util.*;
  * Object validation utilities.
  *
  * @author johnniang
- * @data 03/29/19
+ * @date 03/29/19
  */
 public class ValidationUtils {
 

src/main/java/run/halo/app/web/controller/admin/api/CategoryController.java

@@ -9,7 +9,6 @@ import run.halo.app.model.entity.Category;
 import run.halo.app.model.params.CategoryParam;
 import run.halo.app.model.vo.CategoryVO;
 import run.halo.app.service.CategoryService;
-import run.halo.app.service.PostCategoryService;
 
 import javax.validation.Valid;
 import java.util.List;
@@ -28,11 +27,8 @@ public class CategoryController {
 
     private final CategoryService categoryService;
 
-    private final PostCategoryService postCategoryService;
+    public CategoryController(CategoryService categoryService) {
-
-    public CategoryController(CategoryService categoryService, PostCategoryService postCategoryService) {
         this.categoryService = categoryService;
-        this.postCategoryService = postCategoryService;
     }
 
     @GetMapping
@@ -76,7 +72,6 @@ public class CategoryController {
     @DeleteMapping("{id:\\d+}")
     @ApiOperation("Delete category by id")
     public void deletePermanently(@PathVariable("id") Integer id) {
-        categoryService.removeById(id);
+        categoryService.removeCategoryAndPostCategoryBy(id);
-        postCategoryService.removeByCategoryId(id);
     }
 }