java实现递归菜单树
作者：男人要霸气
这篇文章主要为大家详细介绍了java实现递归菜单树，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下
本文实例为大家分享了java实现递归菜单树的具体代码，供大家参考，具体内容如下
1.表结构
SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for menu
-- ----------------------------
DROP TABLE IF EXISTS `menu`;
CREATE TABLE `menu` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`menu_name` varchar(64) NOT NULL COMMENT '菜单名称',
`order_num` int(11) DEFAULT NULL COMMENT '菜单顺序',
`url` varchar(64) DEFAULT NULL COMMENT '菜单路径',
`pid` varchar(11) DEFAULT NULL COMMENT '上级Id',
`icon` varchar(255) DEFAULT NULL COMMENT '菜单图标',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of menu
-- ----------------------------
INSERT INTO `menu` VALUES ('1', '系统管理', '1', '', '0', null);
INSERT INTO `menu` VALUES ('2', '轨迹查询', '2', '', '0', null);
INSERT INTO `menu` VALUES ('3', '设备信息', '3', '', '0', null);
INSERT INTO `menu` VALUES ('4', '用户信息', '1', '', '1', null);
INSERT INTO `menu` VALUES ('5', '客户信息', '2', null, '1', null);
INSERT INTO `menu` VALUES ('6', '用户资料', '1', null, '4', null);
INSERT INTO `menu` VALUES ('7', '客户资料', '1', null, '5', null);
INSERT INTO `menu` VALUES ('8', '切割机', '1', null, '3', null);
INSERT INTO `menu` VALUES ('9', '铲车', '2', null, '3', null);
INSERT INTO `menu` VALUES ('10', '割片', '1', null, '8', null);
2.菜单实体类
import lombok.Data;
import java.io.Serializable;
import java.util.List;
import javax.persistence.*;
/**
*
* @author m
* @email 123456789@qq.com
* @date 2019-12-13 16:54:59
*/
@Data
@Table(name = "menu")
public class Menu implements Serializable {
private static final long serialVersionUID = 1L;
//
@Id
private Integer id;
//菜单名称
@Column(name = "menu_name")
private String menuName;
//菜单顺序
@Column(name = "order_num")
private Integer orderNum;
//菜单路径
@Column(name = "url")
private String url;
//上级Id
@Column(name = "pid")
private String pid;
//菜单图标
@Column(name = "icon")
private String icon;
//子菜单
@Transient
private List<Menu> children;
}
3.菜单树
/**
* 获取菜单树
* @return
*/
public List<Menu> menuTree() {
//查询所有菜单
List<Menu> menus = mapper.selectAll();
//返回的菜单树
List<Menu> rootMenus = new ArrayList<>();
for (Menu menu : menus) {
//pid（上级Id）为0的是根菜单
if ("0".equals(menu.getPid())) {
rootMenus.add(menu);
}
}
//遍历，找到二级菜单（根菜单的id和所有菜单中的pid比较）
for (Menu rootMenu : rootMenus) {
List<Menu> child = getChild(String.valueOf(rootMenu.getId()), menus);
rootMenu.setChildren(child);
}
return rootMenus;
}
/**
* 递归获取下级菜单
* @param pid 上级Id
* @param menus 所有菜单
* @return
*/
public List<Menu> getChild(String pid, List<Menu> menus) {
//子菜单列表
List<Menu> childList = new ArrayList<>();
for (Menu menu : menus) {
if (pid.equals(menu.getPid())) {
childList.add(menu);
}
}
//遍历 获取子菜单的子菜单
for (Menu menu : childList) {
List<Menu> child = getChild(String.valueOf(menu.getId()), menus);
menu.setChildren(child);
}
//递归出口 childList长度为0
if (childList.size() == 0) {
return new ArrayList<>();
}
return childList;
}
4.测试
{
"status": 200,
"message": "操作成功",
"data": [
{
"id": 1,
"menuName": "系统管理",
"orderNum": 1,
"url": "",
"pid": "0",
"icon": null,
"children": [
{
"id": 4,
"menuName": "用户信息",
"orderNum": 1,
"url": "",
"pid": "1",
"icon": null,
"children": [
{
"id": 6,
"menuName": "用户资料",
"orderNum": 1,
"url": null,
"pid": "4",
"icon": null,
"children": []
}
]
},
{
"id": 5,
"menuName": "客户信息",
"orderNum": 2,
"url": null,
"pid": "1",
"icon": null,
"children": [
{
"id": 7,
"menuName": "客户资料",
"orderNum": 1,
"url": null,
"pid": "5",
"icon": null,
"children": []
}
]
}
]
},
{
"id": 2,
"menuName": "轨迹查询",
"orderNum": 2,
"url": "",
"pid": "0",
"icon": null,
"children": []
},
{
"id": 3,
"menuName": "设备信息",
"orderNum": 3,
"url": "",
"pid": "0",
"icon": null,
"children": [
{
"id": 8,
"menuName": "切割机",
"orderNum": 1,
"url": null,
"pid": "3",
"icon": null,
"children": [
{
"id": 10,
"menuName": "割片",
"orderNum": 1,
"url": null,
"pid": "8",
"icon": null,
"children": []
}
]
},
{
"id": 9,
"menuName": "铲车",
"orderNum": 2,
"url": null,
"pid": "3",
"icon": null,
"children": []
}
]
}
]
}
5.菜单树工具类
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。