Java 使用递归构建树

public class MenuTree1 {
    /**
     * 构建结束的树
     */
    private static List<Menu> menuList ;

/**
 * 构建树
 * @param menuId 树的根节点id  0：代表顶级节点
 * @param nodeList 要构建的数据
 * @return
 */
    public static List<Menu> tree3(Integer menuId, List<MyMenu> nodeList){
        menuList = new ArrayList<Menu>();
        Menu menu1=new Menu();
        menu1.setMenuId(menuId);
        getNode3(menu1,nodeList);
        return menuList;
    }

    /**
     * 使用递归构建树
     * @param menu1
     * @param nodeList
     */
    public static void  getNode3(Menu menu1, List<MyMenu> nodeList){
        Integer menuId =menu1.getMenuId();
        for (MyMenu layer : nodeList) {
            if(menuId.toString().equals(layer.getParentId().toString())){
                Integer menuId1=layer.getMenuId();
                Menu menu=new Menu();
                menu.setMenuId(menuId1);
                menu.setMenuName(layer.getMenuName());
                menu.setParentId(layer.getParentId());
                if (menuId.toString().equals("0")){
                    menuList.add(menu);
                }else {
                    menu1.getChildren().add(menu);
                }
                getNode3(menu,nodeList);
            }
        }

    }
}


@Data
public class MyMenu extends BaseEntity{

    private static final long serialVersionUID = -6525908145032868815L;
@TableId
    private Integer menuId;

    private Integer parentId;

    private String menuName;

    private String icon;

    private Integer type;

    private String url;

    private String permission;

    private Integer sort;
}
@Data
public class Menu {
    private List<Menu> children=new ArrayList<>();
    private Integer parentId;
    private Integer menuId;
    private String menuName;
    private Integer value;
    private String label;

}