目录
一,分析左侧菜单栏及子类的数据表
二,实现左侧菜单栏及子类的具体步骤
2.1实体类(与数据库中的字段对应一一!!!)
2.2dao方法
dao类代码:
TreeOv工具类代码:
2.3action类
2.4BuildTree(将不具有父子格式的数据转成具有父子格式的数据)
2.5配置mvc文件
2.6jsp页面遍历数据
三,总结
前言:我们实现左侧菜单栏功能,我们分析所用到的技术:json,treeov(将没有父子关系的数据转成具有父子关系的数据的方法),each遍历。
看效果:
分析思路:我们首先得获取到具有父子关系的数据,将得到的数据在页面进行遍历。
一,分析左侧菜单栏及子类的数据表
通过表的分析,此表有四个父类,每个父类对应的子类有几个,但是我们通过后台将数据传到前台必须是json格式的数据,才可以完成对应的效果。
二,实现左侧菜单栏及子类的具体步骤
2.1实体类(与数据库中的字段对应一一!!!)
/**
*
*/
package com.zking.entity;
/**
* 实体类
*
* @author 李永安
*
* @date:2023年7月11日 下午7:00:50
*
*/
public class Permission {
private long id;
private String name;
private String description;
private String url;
private long pid;
private int ismenu;
private long displayno;
/**
*
*/
public Permission() {
// TODO Auto-generated constructor stub
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public long getPid() {
return pid;
}
public void setPid(long pid) {
this.pid = pid;
}
public int getIsmenu() {
return ismenu;
}
public void setIsmenu(int ismenu) {
this.ismenu = ismenu;
}
public long getDisplayno() {
return displayno;
}
public void setDisplayno(long displayno) {
this.displayno = displayno;
}
public Permission(long id, String name, String description, String url, long pid, int ismenu, long displayno) {
super();
this.id = id;
this.name = name;
this.description = description;
this.url = url;
this.pid = pid;
this.ismenu = ismenu;
this.displayno = displayno;
}
@Override
public String toString() {
return "Permission [id=" + id + ", name=" + name + ", description=" + description + ", url=" + url + ", pid="
+ pid + ", ismenu=" + ismenu + ", displayno=" + displayno + "]";
}
}
2.2dao方法
我们同过json数据在线解析发现,并不是我们想要的数据!!!
这时我们得去调用框架中的TreeOv工具类 ,build工类去转化
dao类代码:
/**
*
*/
package com.zking.dao;
import java.util.ArrayList;
import java.util.List;
import com.zking.entity.Permission;
import com.zking.util.BaseDao;
import com.zking.util.BuildTree;
import com.zking.util.PageBean;
import com.zking.util.TreeVo;
/**
* 后台左侧数据显示方法
* @author 李永安
*
* @date:2023年7月11日 下午7:05:31
*
*/
public class PermissionDao extends BaseDao<Permission>{
//获取数据库中的数据
public List<Permission> list(Permission Permission, PageBean pageBean) throws Exception {
String sql = "select * from t_easyui_permission where 1=1";
return super.executeQuery(sql, Permission.class, pageBean);
}
public static void main(String[] args) throws Exception {
System.out.println(new PermissionDao().list(new Permission(), null));
}
/**
* 通过Treeov将查询的数据转成具有父子级的数据
* @param Permission
* @return
* @throws Exception
*/
public List<TreeVo<Permission>> menu(Permission Permission ) throws Exception {
List<TreeVo<Permission>> treeov = new ArrayList<TreeVo<Permission>>();
//数据库中的数据
List<com.zking.entity.Permission> list = this.list(Permission, null);
//循环外层
for (Permission p : list) {
TreeVo<Permission> treeVo = new TreeVo<>();//实例TreeVo
treeVo.setId(p.getId()+"");//将p中的属性添加到TreeVo中
treeVo.setText(p.getName());//文本
treeVo.setParentId(p.getPid()+"");
treeov.add(treeVo);
}
//调用工具类build
return BuildTree.buildList(treeov, "0");
}
}
TreeOv工具类代码:
package com.zking.util;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
public class TreeVo<T> {
/**
* 节点ID
*/
private String id;
/**
* 显示节点文本
*/
private String text;
/**
* 节点状态,open closed
*/
private Map<String, Object> state;
/**
* 节点是否被选中 true false
*/
private boolean checked = false;
/**
* 节点属性
*/
private Map<String, Object> attributes;
/**
* 节点的子节点
*/
private List<TreeVo<T>> children = new ArrayList<TreeVo<T>>();
/**
* 父ID
*/
private String parentId;
/**
* 是否有父节点
*/
private boolean hasParent = false;
/**
* 是否有子节点
*/
private boolean hasChildren = false;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getText() {
return text;
}
public void setText(String text) {
this.text = text;
}
public Map<String, Object> getState() {
return state;
}
public void setState(Map<String, Object> state) {
this.state = state;
}
public boolean isChecked() {
return checked;
}
public void setChecked(boolean checked) {
this.checked = checked;
}
public Map<String, Object> getAttributes() {
return attributes;
}
public void setAttributes(Map<String, Object> attributes) {
this.attributes = attributes;
}
public List<TreeVo<T>> getChildren() {
return children;
}
public void setChildren(List<TreeVo<T>> children) {
this.children = children;
}
public boolean isHasParent() {
return hasParent;
}
public void setHasParent(boolean isParent) {
this.hasParent = isParent;
}
public boolean isHasChildren() {
return hasChildren;
}
public void setChildren(boolean isChildren) {
this.hasChildren = isChildren;
}
public String getParentId() {
return parentId;
}
public void setParentId(String parentId) {
this.parentId = parentId;
}
public TreeVo(String id, String text, Map<String, Object> state, boolean checked, Map<String, Object> attributes,
List<TreeVo<T>> children, boolean isParent, boolean isChildren, String parentID) {
super();
this.id = id;
this.text = text;
this.state = state;
this.checked = checked;
this.attributes = attributes;
this.children = children;
this.hasParent = isParent;
this.hasChildren = isChildren;
this.parentId = parentID;
}
public TreeVo() {
super();
}
}
备注:TreeOv工具类:
2.3action类
/**
*
*/
package com.zking.web;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.zking.dao.PermissionDao;
import com.zking.entity.Permission;
import com.zking.framework.ActionSupport;
import com.zking.framework.ModelDriver;
import com.zking.util.ResponseUtil;
import com.zking.util.TreeVo;
/**
* @author 李永安
*
* @date:2023年7月11日 下午8:35:18
*
*/
public class PermissionAction extends ActionSupport implements ModelDriver<Permission> {
private Permission permission ;
private PermissionDao pd = new PermissionDao();
public String menu(HttpServletRequest req, HttpServletResponse resp) throws Exception {
//调用pd中的具有父子关系的数据
List<TreeVo<Permission>> menu = pd.menu(permission);
ResponseUtil.writeJson(resp, menu);//用于传到jsp(data)
return super.execute(req, resp);
}
@Override
public Permission getModel() {
// TODO Auto-generated method stub
return permission;
}
}
2.4BuildTree(将不具有父子格式的数据转成具有父子格式的数据)
package com.zking.util;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class BuildTree {
/**
* 默认-1为顶级节点
* @param nodes
* @param <T>
* @return
*/
public static <T> TreeVo<T> build(List<TreeVo<T>> nodes) {
if (nodes == null) {
return null;
}
List<TreeVo<T>> topNodes = new ArrayList<TreeVo<T>>();
for (TreeVo<T> children : nodes) {
String pid = children.getParentId();
if (pid == null || "-1".equals(pid)) {
topNodes.add(children);
continue;
}
for (TreeVo<T> parent : nodes) {
String id = parent.getId();
if (id != null && id.equals(pid)) {
parent.getChildren().add(children);
children.setHasParent(true);
parent.setChildren(true);
continue;
}
}
}
TreeVo<T> root = new TreeVo<T>();
if (topNodes.size() == 1) {
root = topNodes.get(0);
} else {
root.setId("000");
root.setParentId("-1");
root.setHasParent(false);
root.setChildren(true);
root.setChecked(true);
root.setChildren(topNodes);
root.setText("顶级节点");
Map<String, Object> state = new HashMap<>(16);
state.put("opened", true);
root.setState(state);
}
return root;
}
/**
* 指定idparam为顶级节点
* @param nodes
* @param idParam
* @param <T>
* @return
*/
public static <T> List<TreeVo<T>> buildList(List<TreeVo<T>> nodes, String idParam) {
if (nodes == null) {
return null;
}
List<TreeVo<T>> topNodes = new ArrayList<TreeVo<T>>();
for (TreeVo<T> children : nodes) {
String pid = children.getParentId();
if (pid == null || idParam.equals(pid)) {
topNodes.add(children);
continue;
}
for (TreeVo<T> parent : nodes) {
String id = parent.getId();
if (id != null && id.equals(pid)) {
parent.getChildren().add(children);
children.setHasParent(true);
parent.setChildren(true);
continue;
}
}
}
return topNodes;
}
}
2.5配置mvc文件
<action path="/permission" type="com.zking.web.PermissionAction">
</action>
2.6jsp页面遍历数据
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@include file="/common/public.jsp"%>
<!DOCTYPE>
<html>
<head>
<script type="text/javascript"></script>
</head>
<body>
<div class="layui-layout layui-layout-admin">
<div class="layui-header">
<div class="layui-logo layui-hide-xs layui-bg-black">layout
demo</div>
<!-- 头部区域(可配合layui 已有的水平导航) -->
<ul class="layui-nav layui-layout-left">
<!-- 移动端显示 -->
<li class="layui-nav-item layui-show-xs-inline-block layui-hide-sm"
lay-header-event="menuLeft"><i
class="layui-icon layui-icon-spread-left"></i></li>
<!-- Top导航栏 -->
<li class="layui-nav-item layui-hide-xs"><a href="">nav 1</a></li>
<li class="layui-nav-item layui-hide-xs"><a href="">nav 2</a></li>
<li class="layui-nav-item layui-hide-xs"><a href="">nav 3</a></li>
<li class="layui-nav-item"><a href="javascript:;">nav
groups</a>
<dl class="layui-nav-child">
<dd>
<a href="">menu 11</a>
</dd>
<dd>
<a href="">menu 22</a>
</dd>
<dd>
<a href="">menu 33</a>
</dd>
</dl></li>
</ul>
<!-- 个人头像及账号操作 -->
<ul class="layui-nav layui-layout-right">
<li class="layui-nav-item layui-hide layui-show-md-inline-block">
<a href="javascript:;"> <img
src="//tva1.sinaimg.cn/crop.0.0.118.118.180/5db11ff4gw1e77d3nqrv8j203b03cweg.jpg"
class="layui-nav-img"> tester
</a>
<dl class="layui-nav-child">
<dd>
<a href="">Your Profile</a>
</dd>
<dd>
<a href="">Settings</a>
</dd>
<dd>
<a href="login.jsp">Sign out</a>
</dd>
</dl>
</li>
<li class="layui-nav-item" lay-header-event="menuRight" lay-unselect>
<a href="javascript:;"> <i
class="layui-icon layui-icon-more-vertical"></i>
</a>
</li>
</ul>
</div>
<div class="layui-side layui-bg-black">
<div class="layui-side-scroll">
<!-- 左侧导航区域(可配合layui已有的垂直导航) -->
<ul id="menu" class="layui-nav layui-nav-tree" lay-filter="menu">
<li class="layui-nav-item layui-nav-itemed"><a class=""
href="javascript:;">menu group 1</a>
<dl class="layui-nav-child">
<dd>
<a href="javascript:;">menu 1</a>
</dd>
<dd>
<a href="javascript:;">menu 2</a>
</dd>
<dd>
<a href="javascript:;">menu 3</a>
</dd>
<dd>
<a href="">the links</a>
</dd>
</dl></li>
<li class="layui-nav-item"><a href="javascript:;">menu
group 2</a>
<dl class="layui-nav-child">
<dd>
<a href="javascript:;">list 1</a>
</dd>
<dd>
<a href="javascript:;">list 2</a>
</dd>
<dd>
<a href="">超链接</a>
</dd>
</dl></li>
<li class="layui-nav-item"><a href="javascript:;">click
menu item</a></li>
<li class="layui-nav-item"><a href="">the links</a></li>
</ul>
</div>
</div>
<div class="layui-body">
<!-- 内容主体区域 -->
<div style="padding: 15px;">内容主体区域。记得修改 layui.css 和 js 的路径</div>
</div>
<div class="layui-footer">
<!-- 底部固定区域 -->
底部固定区域
</div>
</div>
<script>
//JS
layui.use(['jquery'], function(){
let $ = layui.jquery;
$.ajax({
url:'${pageContext.request.contextPath }/permission.action?methodName=menu',
dataType:'json',
method:'post',
success:function(data){//数据回显
console.log(data);
let htmlstr = '';
//通过each遍历
$.each(data,function(i,n){
htmlstr += '<li class="layui-nav-item layui-nav-itemed">';
htmlstr += '<a class="" href="javascript:;">'+data[i].text+'</a>';
//是否存在下一级,如果有就继续遍历
if(data[i].hasChildren){
htmlstr += '<dl class="layui-nav-child">';
let children =data[i].children;
$.each(children,function(ind,nod){
htmlstr += '<dd><a href="javascript:;">'+children[ind].text+'</a></dd>';
})
htmlstr += '</dl>';
}
htmlstr += '</li>';
})
//将htmlstr加入ul的id中
$("#menu").html(htmlstr);
element.render('menu');
}
});
});
</script>
</body>
</html>
注:千万不要忘了加载 element模块。
element.render('menu');
运行就可以达到效果了!!!
三,总结
学习 Layui 需要从基础的概念和用法入手,通过文档、示例和社区资源来掌握和运用 Layui 的各种功能和技巧。坚持实践和持续学习,可以帮助您逐步成为 Layui 的熟练开发者。加油!!!
好了,就讲到这里了希望这篇博客能够帮助到您!!!文章来源:https://www.toymoban.com/news/detail-550347.html
文章来源地址https://www.toymoban.com/news/detail-550347.html
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