1.需求场景

数据库后台返回树形结构菜单，实现菜单排序。

2.项目环境

spring spring mvc mybatis  mysql

3.实现方法

对应的实体类

private int id;// '主键ID',

private String cname;// '菜单名称',

private int pid;// '父级ID',默认0

private String redirect;// '菜单地址',

private String creator;// '创建者',

private String updatedate;// '修改日期',

private String updator;// '修改者',

private String createdate;// '创建日期',

private double sortid;//菜单排序字段 默认0

private List children;//父菜单下的子菜单封装树形数据

public class TreeUtil {

private int count = 0;

private List nodes;

public TreeUtil(List nodes){

this.nodes = nodes;

}

public List buildTree(){

List list = new ArrayList();

for (AuthUser node : nodes) {

if (node.getPid() == 0) {

list.add(node);

}

}

list = getSortChildren(list);

for (AuthUser node : list) {

build(node);

}

return list;

}

/***

* 构建权限树

* @Title: build

* @Description: TODO

* @param node

*/

private void build(AuthUser node){

List children = getChildren(node);

if (!children.isEmpty()) {

node.setChildren(children);

if(count <3){

//children.get(0).setChecked("true");//设置默认选中

count ++;

}

for (AuthUser child : children) {

build(child);

}

}

}

/**

*

* @Title: getChildren

* @Description: TODO 获取子节点

* @param node

* @return

*/

private List getChildren(AuthUser node){

List children = new ArrayList();

Integer id = node.getId();

for (AuthUser child : nodes) {

if (id==child.getPid()) {

children.add(child);

}

}

return getSortChildren(children);

// return children;

}

/**

*

* @Title: getChildren

* @Description: TODO 获取排序子节点

* @param node

* @return

*/

private List getSortChildren(List children){

MyCompare my = new MyCompare();

Collections.sort(children,my) ;

return children;

}

}自定义比较器

public class MyCompare implements Comparator{

@Override

public int compare(AuthUser o1, AuthUser o2) {

if(o1.getSortid()

return -1;

}else{

return 1;

}

}

}

数据库返回

public void getauthinfo(Map param){

List authList =userRoleService.getUserAuthTree(param); //执行查询

TreeUtil tree = new TreeUtil(authList);

//返回按照sortid排好序的树形结构的菜单

List datalist = tree.buildTree();

}

} catch (Exception e) {

e.printStackTrace();

}

}