递归加载菜单树

1.创建数据库表

create table system_resource
(
id bigint(11) not null primary key auto_increment comment ‘id‘,
resource_name varchar(20) not null comment ‘资源名称‘,
resource_name_cn varchar(20) not null comment ‘资源中文名‘,
resource_parent_name varchar(20) null comment ‘父级资源名称‘,
resource_url varchar(100) null comment ‘资源路径‘,
resource_icon varchar(100) comment ‘资源图标‘,
create_time timestamp not null default ‘0000-00-00 00:00:00‘ comment ‘创建时间‘,
update_time timestamp not null default current_timestamp on update current_timestamp comment ‘修改时间‘
) charset = utf8mb4 comment ‘角色资源表‘;
create trigger resource_insert
before insert
on system_resource
for each row set new.create_time = now();

插入测试数据：

然后java代码加载菜单树：

新建一个菜单的bean对象，用来存放加载出来的菜单：

package com.whx.gxrsms.bean;

import lombok.Data;
import lombok.experimental.Accessors;

import java.io.Serializable;
import java.util.List;

/**

/span>@author</span ZhaoShuai
@company lihfinance.com
@date Create in 2020/3/3
/
@Data
@Accessors(chain = true)
public class MenuTree implements Serializable {

private static final long serialVersionUID = 1L;

private Long id;

private String name;

private String title;

private String icon;

private String href;

private List list;
}

使用mybatis和通用mapper来写dao层，这一块就不写出来了，直接写主要方法：

@Override
public List getMenuTree() {
/加载出所有的菜单/
List resources = resourceMapper.select(new SystemResource());
/筛选出所有的第一级菜单/
List menuTrees = resources.parallelStream().filter(r -> StringUtils.isEmpty(r.getResourceParentName()))
.map(this::convertResource)
.collect(Collectors.toList());
/加载出所有的子菜单/
List childResource = resources.parallelStream()
.filter(f -> !StringUtils.isEmpty(f.getResourceParentName()))
.collect(Collectors.toList());
/生成菜单树/
menuTrees = menuTrees.parallelStream().map(m -> recursiveMenu(m, childResource)).collect(Collectors.toList());
```
return menuTrees;
```
}
/**
- @company lihfinance.com
- /span>@author@param@return menuTree.getName().equals(r.getResourceParentName()))
 .map(this::convertResource).collect(Collectors.toList());
 if (!childMenu.isEmpty()) {
 childMenu = childMenu.parallelStream().map(m -> recursiveMenu(m, resources)).collect(Collectors.toList());
 }
 menuTree.setList(childMenu);
 return menuTree;
 }
/**
- @company lihfinance.com
- /span>@author@param@return</span
 /
 private MenuTree convertResource(SystemResource resource) {
 MenuTree tree = new MenuTree();
 tree.setId(resource.getId());
 tree.setName(resource.getResourceName());
 tree.setTitle(resource.getResourceNameCn());
 tree.setHref(resource.getResourceUrl());
 tree.setIcon(resource.getResourceIcon());
 return tree;
 }
 
 然后配置controller,访问调用该方法：
 
 @RequestMapping("/getMenuTree")
 @ResponseBody
 public Result getMenuTree() {
 Result result = Result.success();
 
 List menuTrees = loginService.getMenuTree();
 result.setData(menuTrees);
 return result;
 }
 
 页面展示结果为：
 
 {"code":200,"msg":"操作成功","data":[{"id":1,"name":"system.manager","title":"系统管理","icon":"aaa","href":null,"list":[{"id":2,"name":"save.resource","title":"添加资源","icon":"bbb","href":"/gxrsms/resource.html","list":[]},{"id":3,"name":"role.manager","title":"角色管理","icon":null,"href":null,"list":[{"id":5,"name":"role.add","title":"添加角色","icon":"","href":"/gxrsms/role/insert","list":[]}]},{"id":4,"name":"user.manager","title":"用户管理","icon":null,"href":null,"list":[{"id":6,"name":"user.add","title":"添加用户","icon":"","href":"/gxrsms/user/insert","list":[]}]}]},{"id":7,"name":"dept.manager","title":"部门管理","icon":"ccc","href":null,"list":[{"id":8,"name":"dept.add","title":"添加部门","icon":"","href":"/gxrsms/dept/insert","list":[]}]}]}
 
 这就是我们要加载的菜单树了，json格式化后可以清楚的看出层级结构。