java生成json无级菜单树

利用java生成json无级菜单树

最近做毕业设计时要用到前后端分离，利用json传递数据，而多级菜单数据需要以json形式返回给前端页面，因此记录一下相关的方法 ，废话不多说，直接上代码。

MenuTree是实现的主要方法

package cn.xyes.entity;

import java.util.ArrayList;
import java.util.List;

/**
* @author Tireless
*/
public class MenuTree {
private List

menuList = new ArrayList();
public MenuTree(List menuList) {
this.menuList=menuList;
}

//建立树形结构
public List

builTree(){
List treeMenus =new ArrayList();
for(Menu menuNode : getRootNode()) {
menuNode=buildChilTree(menuNode);
treeMenus.add(menuNode);
}
return treeMenus;
}

//递归，建立子树形结构
private Menu buildChilTree(Menu pNode){
List

chilMenus =new ArrayList();
for(Menu menuNode : menuList) {
if(menuNode.getParent_id().equals(pNode.getId())) {
chilMenus.add(buildChilTree(menuNode));
}
}
pNode.setChildren(chilMenus);
return pNode;
}

//获取根节点
private List

getRootNode() {
List rootMenuLists =new ArrayList();
for(Menu menuNode : menuList) {
if(menuNode.getParent_id().equals("0")) {
rootMenuLists.add(menuNode);
}
}
return rootMenuLists;
}
}

Menu是实体类可根据自身需要修改

package cn.xyes.entity;

import java.util.List;

/**
* @author Tireless
*/
public class Menu {
//菜单id
private String id;
//菜单名称
private String name;
//父菜单id
private String parent_id;
private List

children;

public Menu(String id, String name, String parent_id) {
this.id = id;
this.name = name;
this.parent_id = parent_id;
}

public String getId() {
return id;
}

public void setId(String id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getParent_id() {
return parent_id;
}

public void setParent_id(String parent_id) {
this.parent_id = parent_id;
}

public List

getChildren() {
return children;
}

public void setChildren(List

children) {
this.children = children;
}

@Override
public String toString() {
return "Menu{" +
"id='" + id + ''' +
", name='" + name + ''' +
", parent_id='" + parent_id + ''' +
", children=" + children +
'}';
}
}
测试代码
-

/**
*json返回数据
**/
@RequestMapping("/demo")
@ResponseBody
public JsonResult jsonResult(){
List

menu = new ArrayList<>();
//实际开发中可以使用数据库中查询到的数据替换下面数据
menu.add(new Menu("1","一级菜单1","0"));
menu.add(new Menu("2","一级菜单2","0"));
menu.add(new Menu("3","二级菜单1","1"));
menu.add(new Menu("4","二级菜单2","1"));
menu.add(new Menu("5","三级菜单1","3"));

// 先找到所有的一级菜单
MenuTree menuTree =new MenuTree(menu);
menu=menuTree.builTree();
return new JsonResult(menu,StatusCode.SUCCESS);
}
}

返回json数据样式

[
{
"id": "1",
"name": "一级菜单1",
"parent_id": "0",
"children": [
{
"id": "3",
"name": "二级菜单1",
"parent_id": "1",
"children": [
{
"id": "5",
"name": "三级菜单1",
"parent_id": "3",
"children": []
}
]
},
{
"id": "4",
"name": "二级菜单2",
"parent_id": "1",
"children": []
}
]
},
{
"id": "2",
"name": "一级菜单2",
"parent_id": "0",
"children": []
}
]
这里就不再贴效果图了，懂得都懂。