fix:组合模式和访问者模式

src/main/java/com/study/design/MockDb.java → src/main/java/com/study/design/items/MockDb.java

-package com.study.design;
+package com.study.design.items;
 
 import com.study.design.items.node.ProductItem;
 
 import java.util.ArrayList;
 import java.util.List;
 
+
+/**
+ * 多级目录mock数据
+ *
+ * @author : qinyingjie
+ * @version : 2.2.0
+ * @date : 2023/7/30 19:46
+ */
 public class MockDb {
     public static ProductItem ProductItem = new ProductItem();
 

src/main/java/com/study/design/items/node/AbstractProductItem.java

 package com.study.design.items.node;
 
+
+/**
+ * 抽象节点
+ *
+ * @author : qinyingjie
+ * @version : 2.2.0
+ * @date : 2023/7/30 19:48
+ */
 public abstract class AbstractProductItem {
+    /**
+     * 删除子节点
+     *
+     * @param item
+     */
     public abstract void removeChild(AbstractProductItem item);
+
+    /**
+     * 新增子节点
+     *
+     * @param item
+     */
     public abstract void addChild(AbstractProductItem item);
 }

src/main/java/com/study/design/items/node/ProductItem.java

@@ -4,16 +4,36 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
-public class ProductItem extends AbstractProductItem{
+
+/**
+ * 数据节点
+ *
+ * @author : qinyingjie
+ * @version : 2.2.0
+ * @date : 2023/7/30 19:47
+ */
+public class ProductItem extends AbstractProductItem {
+    /**
+     * id
+     */
     private int id;
+    /**
+     * 父id
+     */
     private int pid;
+    /**
+     * 名称
+     */
     private String name;
+    /**
+     * 子节点集合
+     */
     private List<ProductItem> child = new ArrayList<>();
 
     @Override
     public void removeChild(AbstractProductItem item) {
         ProductItem removeItem = (ProductItem) item;
-        this.child = child.stream().filter(x->x.getId() != removeItem.getId()).collect(Collectors.toList());
+        this.child = child.stream().filter(x -> x.getId() != removeItem.getId()).collect(Collectors.toList());
     }
 
     @Override

src/main/java/com/study/design/items/visitor/AddItemVisitor.java

 package com.study.design.items.visitor;
 
-import com.study.design.MockDb;
+import com.study.design.items.MockDb;
 import com.study.design.items.node.ProductItem;
 import org.springframework.stereotype.Component;
 
+
+/**
+ * 添加节点访问者
+ *
+ * @author : qinyingjie
+ * @version : 2.2.0
+ * @date : 2023/7/30 19:46
+ */
 @Component
-public class AddItemVisitor implements ItemVisitor<ProductItem>{
-    // 入参是 id 2, pid为 1
+public class AddItemVisitor implements ItemVisitor<ProductItem> {
+
     @Override
     public ProductItem visitor(ProductItem productItem) {
         ProductItem currentItem = MockDb.ProductItem; //  从缓存来的 to do
-        if(productItem.getId() == currentItem.getId()) {
+        if (productItem.getId() == currentItem.getId()) {
             throw new UnsupportedOperationException("根节点是唯一的。");
         }
-        if(productItem.getPid() == currentItem.getId()) {
+        if (productItem.getPid() == currentItem.getId()) {
             currentItem.addChild(productItem);
             return currentItem;
         }
@@ -22,8 +30,8 @@ public class AddItemVisitor implements ItemVisitor<ProductItem>{
     }
 
     private void addChild(ProductItem productItem, ProductItem currentItem) {
-        for(ProductItem item : currentItem.getChild()) {
-            if(item.getId() == productItem.getPid()) {
+        for (ProductItem item : currentItem.getChild()) {
+            if (item.getId() == productItem.getPid()) {
                 item.addChild(productItem);
                 break;
             } else {

src/main/java/com/study/design/items/visitor/DelItemVisitor.java

 package com.study.design.items.visitor;
 
-import com.study.design.MockDb;
+import com.study.design.items.MockDb;
 import com.study.design.items.node.ProductItem;
 import org.springframework.stereotype.Component;
 
+
+/**
+ * 删除节点访问者
+ *
+ * @author : qinyingjie
+ * @version : 2.2.0
+ * @date : 2023/7/30 19:46
+ */
 @Component
-public class DelItemVisitor implements ItemVisitor<ProductItem>{
-    // 入参是 id 2, pid为 1
+public class DelItemVisitor implements ItemVisitor<ProductItem> {
+
     @Override
     public ProductItem visitor(ProductItem productItem) {
         ProductItem currentItem = MockDb.ProductItem; //  从缓存来的 to do
-        if(productItem.getId() == currentItem.getId()) {
+        if (productItem.getId() == currentItem.getId()) {
             throw new UnsupportedOperationException("根节点不能删。");
         }
-        if(productItem.getPid() == currentItem.getId()) {
+        if (productItem.getPid() == currentItem.getId()) {
             currentItem.removeChild(productItem);
             return currentItem;
         }
@@ -22,8 +30,8 @@ public class DelItemVisitor implements ItemVisitor<ProductItem>{
     }
 
     private void delChild(ProductItem productItem, ProductItem currentItem) {
-        for(ProductItem item : currentItem.getChild()) {
-            if(item.getId() == productItem.getPid()) {
+        for (ProductItem item : currentItem.getChild()) {
+            if (item.getId() == productItem.getPid()) {
                 item.removeChild(productItem);
                 break;
             } else {

src/main/java/com/study/design/items/visitor/ItemVisitor.java

@@ -2,6 +2,20 @@ package com.study.design.items.visitor;
 
 import com.study.design.items.node.ProductItem;
 
+
+/**
+ * 访问者接口
+ *
+ * @author : qinyingjie
+ * @version : 2.2.0
+ * @date : 2023/7/30 19:46
+ */
 public interface ItemVisitor<T> {
+    /**
+     * 访问行为
+     *
+     * @param productItem
+     * @return
+     */
     T visitor(ProductItem productItem);
 }

src/main/java/com/study/design/service/ItemService.java

 package com.study.design.service;
 
-import com.study.design.MockDb;
+import com.study.design.items.MockDb;
 import com.study.design.items.node.ProductItem;
 import com.study.design.items.visitor.AddItemVisitor;
 import com.study.design.items.visitor.DelItemVisitor;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
+/**
+ * 树结构节点service
+ *
+ * @author : qinyingjie
+ * @version : 2.2.0
+ * @date : 2023/7/30 19:49
+ */
 @Service
 public class ItemService {
+
     @Autowired
     private DelItemVisitor delItemVisitor;
-
     @Autowired
     private AddItemVisitor addItemVisitor;