课程分类

src/main/java/xyz/playedu/api/service/CourseCategoryService.java

@@ -0,0 +1,26 @@
+package xyz.playedu.api.service;
+
+import xyz.playedu.api.domain.CourseCategory;
+import com.baomidou.mybatisplus.extension.service.IService;
+import xyz.playedu.api.exception.NotFoundException;
+
+import java.util.List;
+
+/**
+ * @author tengteng
+ * @description 针对表【course_categories】的数据库操作Service
+ * @createDate 2023-02-24 13:55:19
+ */
+public interface CourseCategoryService extends IService<CourseCategory> {
+
+    List<CourseCategory> listByParentId(Integer id);
+
+    List<CourseCategory> all();
+
+    CourseCategory findOrFail(Integer id) throws NotFoundException;
+
+    void deleteById(Integer id) throws NotFoundException;
+
+    void update(CourseCategory category, String name, Integer parentId, Integer sort) throws NotFoundException;
+
+}

src/main/java/xyz/playedu/api/service/impl/CourseCategoryServiceImpl.java

@@ -0,0 +1,119 @@
+package xyz.playedu.api.service.impl;
+
+import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
+import org.springframework.transaction.annotation.Transactional;
+import xyz.playedu.api.bus.CourseCategoryBus;
+import xyz.playedu.api.domain.CourseCategory;
+import xyz.playedu.api.exception.NotFoundException;
+import xyz.playedu.api.service.CourseCategoryService;
+import xyz.playedu.api.mapper.CourseCategoryMapper;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author tengteng
+ * @description 针对表【course_categories】的数据库操作Service实现
+ * @createDate 2023-02-24 13:55:19
+ */
+@Service
+public class CourseCategoryServiceImpl extends ServiceImpl<CourseCategoryMapper, CourseCategory> implements CourseCategoryService {
+
+    @Override
+    public List<CourseCategory> listByParentId(Integer id) {
+        return list(query().getWrapper().eq("parent_id", id).orderByAsc("sort"));
+    }
+
+    @Override
+    public List<CourseCategory> all() {
+        return list(query().getWrapper().orderByAsc("sort"));
+    }
+
+    @Override
+    public CourseCategory findOrFail(Integer id) throws NotFoundException {
+        CourseCategory category = getById(id);
+        if (category == null) {
+            throw new NotFoundException("分类不存在");
+        }
+        return category;
+    }
+
+    @Override
+    @Transactional
+    public void deleteById(Integer id) throws NotFoundException {
+        CourseCategory category = findOrFail(id);
+        //更新parent_chain
+        updateParentChain(category.getParentChain(), CourseCategoryBus.childrenParentChain(category));
+        //删除记录
+        removeById(category.getId());
+    }
+
+    @Override
+    @Transactional
+    public void update(CourseCategory category, String name, Integer parentId, Integer sort) throws NotFoundException {
+        String childrenChainPrefix = CourseCategoryBus.childrenParentChain(category);
+
+        CourseCategory data = new CourseCategory();
+        data.setId(category.getId());
+
+        if (!category.getName().equals(name)) {
+            data.setName(name);
+        }
+
+        if (!category.getParentId().equals(parentId)) {
+            data.setParentId(parentId);
+            if (parentId.equals(0)) {
+                data.setParentChain("");
+            } else {
+                CourseCategory parentCourseCategory = findOrFail(parentId);
+                data.setParentChain(CourseCategoryBus.childrenParentChain(parentCourseCategory));
+            }
+        }
+        if (!category.getSort().equals(sort)) {
+            data.setSort(sort);
+        }
+
+        //提交更换
+        updateById(data);
+
+        category = getById(category.getId());
+        updateParentChain(CourseCategoryBus.childrenParentChain(category), childrenChainPrefix);
+    }
+
+    private void updateParentChain(String newChildrenPC, String oldChildrenPC) {
+        List<CourseCategory> children = list(query().getWrapper().like("parent_chain", oldChildrenPC + "%"));
+        if (children.size() == 0) {
+            return;
+        }
+
+        ArrayList<CourseCategory> updateRows = new ArrayList<>();
+        for (CourseCategory tmpCourseCategory : children) {
+            CourseCategory tmpUpdateCourseCategory = new CourseCategory();
+            tmpUpdateCourseCategory.setId(tmpCourseCategory.getId());
+
+            // parentChain计算
+            String pc = newChildrenPC;
+            if (!tmpCourseCategory.getParentChain().equals(oldChildrenPC)) {
+                pc = tmpCourseCategory.getParentChain().replaceFirst(oldChildrenPC + ",", newChildrenPC.length() == 0 ? newChildrenPC : newChildrenPC + ',');
+            }
+            tmpUpdateCourseCategory.setParentChain(pc);
+
+            // parentId计算
+            int parentId = 0;
+            if (pc != null && pc.length() > 0) {
+                String[] parentIds = pc.split(",");
+                parentId = Integer.parseInt(parentIds[parentIds.length - 1]);
+            }
+            tmpUpdateCourseCategory.setParentId(parentId);
+
+            updateRows.add(tmpUpdateCourseCategory);
+        }
+        updateBatchById(updateRows);
+    }
+
+}
+
+
+
+