Java实现多级菜单(递归实现)

港控/mmm° 2022-12-22 08:47 514阅读 0赞

### Java实现多级菜单 ###

##### 菜单管理数据库设计 #####

pgsql表

CREATE TABLE "ads"."sys_menu_permission" (
    "menu_id" int4 DEFAULT nextval('"ads".sys_menu_permission_menu_id_seq'::regclass) NOT NULL,
    "menu_pid" int4 DEFAULT 0,
    "menu_name" varchar(100) COLLATE "default",
    "menu_type" varchar(20) COLLATE "default",
    "url" varchar(100) COLLATE "default",
    "active" varchar(1) COLLATE "default" DEFAULT 1,
    "visible" varchar(1) COLLATE "default" DEFAULT 1,
    "sort" int4 DEFAULT 0,
    "level" int4,
    "icon" varchar(100) COLLATE "default",
    "created_at" timestamp DEFAULT now(),
    CONSTRAINT "sys_menu_permission_pkey" PRIMARY KEY ("menu_id")
    )
    WITH (OIDS=FALSE)
    ;

##### 菜单管理实体类 #####

@Data
    public class SysMenuPermissionEntityParent extends BaseEntity { 
    	private static final long serialVersionUID = 1L;
    	
    	/** * ID */
    	private Integer menuId;
    	/** * 菜单父ID */
    	private Integer menuPid;
    	/** * 菜单名称 */
    	private String menuName;
    	/** * 菜单类型(menu, permission) */
    	private String menuType;
    
    	List<SysMenuPermissionEntity> children;
    	
    	/** * 路由地址 */
    	private String url;
    	/** * 是否可用(1:可用;0:不可用) */
    	private String active;
    	/** * 是否可见(1:可见;0:不可见) */
    	private String visible;
    	/** * 组内排序 */
    	private Integer sort;
    	/** * 菜单层级 */
    	private Integer level;
    	/** * 矢量图标 */
    	private String icon;
    	/** * 创建时间 */
    	private Date createdAt;
    }

##### Controller 层 #####

/** * 查询菜单列表(递归查询) * @return */
    @ApiOperation("递归查询菜单列表")
    @GetMapping("/findMenuList")
    @IgnoreServiceAuth
    public Map<String, Object> findMenuList() { 
    	return sysMenuPermissionService.findMenuList();
    }

##### Service 层 #####

@Override
    public Map<String, Object> findMenuList() { 
        Map<String, Object> data = new HashMap<>();
        try {  //查询所有菜单
            List<SysMenuPermissionEntity> allMenu = sysMenuPermissionMapper.queryList();
            //根节点集合
            List<SysMenuPermissionEntity> rootMenu = new ArrayList<>();
            for (SysMenuPermissionEntity entity : allMenu) { 
                if (entity.getMenuPid() == 0) {  //父节点是0的，为根节点。
                    rootMenu.add(entity);
                }
            }
            /* 根据Menu类的order排序 */
            //Collections.sort(rootMenu, order());
            //为根菜单设置子菜单，getClild是递归调用的
            for (SysMenuPermissionEntity entity : rootMenu) { 
                /* 获取根节点下的所有子节点 使用getChild方法*/
                List<SysMenuPermissionEntity> childList = getChild(entity.getMenuId().toString(), allMenu);
                entity.setChildren(childList);//给根节点设置子节点
            }
            /** * 输出构建好的菜单数据。 */
            data.put("code", "0");
            data.put("msg", "ok");
            data.put("result", rootMenu);
            return data;
        } catch (Exception e) { 
            data.put("code", "-1");
            data.put("result", new ArrayList());
            return data;
        }
    }
    
    /** * 获取子节点 * * @param id 父节点id * @param allMenu 所有菜单列表 * @return 每个根节点下，所有子菜单列表 */
    public List<SysMenuPermissionEntity> getChild(String id, List<SysMenuPermissionEntity> allMenu) { 
        //子菜单
        List<SysMenuPermissionEntity> childList = new ArrayList<>();
        for (SysMenuPermissionEntity entity : allMenu) { 
            // 遍历所有节点，将所有菜单的父id与传过来的根节点的id比较
            //相等说明：为该根节点的子节点。
            if (entity.getMenuPid().toString().equals(id)) { 
                childList.add(entity);
            }
        }
        //递归
        for (SysMenuPermissionEntity entity : childList) { 
            entity.setChildren(getChild(entity.getMenuId().toString(), allMenu));
        }
        //Collections.sort(childList,order()); //排序
        //如果节点下没有子节点，返回一个空List（递归退出）
        if (childList.size() == 0) { 
            return new ArrayList<>();
        }
        return childList;
    }

##### Dao 层 #####

<select id="queryList" resultMap="ResultMap">
    	select
    	<include refid="Column_List" />
    	from ads.sys_menu_permission
    	<include refid="Example_Where_Clause" />
    	<if test="orderBy != null and orderBy != ''">
    		order by ${ orderBy}
    	</if>
    </select>

##### 模拟表数据 #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3OTg5OTgw_size_16_color_FFFFFF_t_70_pic_center]

##### 返回给前端的JSON数据 #####

{ 
      "msg": "ok",
      "result": [
        { 
          "menuId": 1,
          "menuPid": 0,
          "menuName": "test menu",
          "menuType": "menu",
          "active": "1",
          "visible": "1",
          "sort": 0,
          "level": 1,
          "createdAt": "2020-11-03 00:00:00",
          "children": [
            { 
              "menuId": 6,
              "menuPid": 1,
              "menuName": "ggg",
              "children": [
                { 
                  "menuId": 12,
                  "menuPid": 6,
                  "menuName": "sads2c",
                  "menuType": "22r32sac",
                  "url": "sfafa2s",
                  "active": "1",
                  "visible": "1",
                  "sort": 0,
                  "createdAt": "2020-11-18 18:05:14",
                  "children": []
                }
              ]
            },
            { 
              "menuId": 3,
              "menuPid": 1,
              "menuName": "string",
              "menuType": "string",
              "url": "string",
              "active": "1",
              "visible": "s",
              "sort": 0,
              "level": 0,
              "createdAt": "2020-11-16 17:00:00",
              "children": [
                { 
                  "menuId": 9,
                  "menuPid": 3,
                  "menuName": "dsdsaf",
                  "menuType": "sadfas",
                  "url": "sfas",
                  "active": "1",
                  "visible": "1",
                  "sort": 0,
                  "createdAt": "2020-11-18 18:04:42",
                  "children": []
                },
                { 
                  "menuId": 10,
                  "menuPid": 3,
                  "menuName": "dsaf2sdsc",
                  "menuType": "fasdf",
                  "url": "sdfasd",
                  "active": "1",
                  "visible": "1",
                  "sort": 0,
                  "createdAt": "2020-11-18 18:04:53",
                  "children": []
                }
              ]
            },
            { 
              "menuId": 4,
              "menuPid": 1,
              "menuName": "hhh",
              "menuType": "hhh",
              "url": "hhh",
              "active": "1",
              "visible": "0",
              "sort": 0,
              "level": 0,
              "icon": "hhh",
              "createdAt": "2020-11-16 17:00:00",
              "children": [
                { 
                  "menuId": 11,
                  "menuPid": 4,
                  "menuName": "2dsaf",
                  "menuType": "asf2dhg",
                  "url": "hgfgj",
                  "active": "1",
                  "visible": "1",
                  "sort": 0,
                  "createdAt": "2020-11-18 18:05:02",
                  "children": []
                }
              ]
            }
          ]
        },
        { 
          "menuId": 2,
          "menuPid": 0,
          "menuName": "test2",
          "menuType": "menu",
          "active": "1",
          "visible": "1",
          "sort": 0,
          "createdAt": "2020-11-03 15:31:20",
          "children": [
            { 
              "menuId": 7,
              "menuPid": 2,
              "menuName": "dfa",
              "menuType": "dfa",
              "url": "fadfa",
              "active": "1",
              "visible": "1",
              "sort": 0,
              "createdAt": "2020-11-18 17:43:11",
              "children": []
            },
            { 
              "menuId": 8,
              "menuPid": 2,
              "menuName": "2333",
              "menuType": "safa23",
              "url": "dfas3c",
              "active": "1",
              "visible": "1",
              "sort": 0,
              "icon": "",
              "createdAt": "2020-11-18 17:43:31",
              "children": []
            },
            { 
              "menuId": 5,
              "menuPid": 2,
              "menuName": "sfas",
              "menuType": "23",
              "url": "232fdsfa",
              "active": "1",
              "visible": "1",
              "sort": 0,
              "createdAt": "2020-11-18 17:46:11",
              "children": []
            }
          ]
        }
      ],
      "code": "0"
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3OTg5OTgw_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/0c04f60da6cb4d2bbacc95781a44da67.png