LayUI之树形菜单的实现

package com.junlinyi.entity;
/**
 * 菜单权限实体类
 * 
 * @author 君临沂
 */
public class Permission {
  private long id;
  private String name;
  private String description;
  private String url;
  private long pid;
  private int ismenu;//控制当前系统的权限是菜单还是按钮
  private long displayno;//菜单排序字段
  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 + "]";
  }
}

package com.zking.util;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
 * 权限工具类
 * 
 * @author 君临沂
 */
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();
  }
}

package com.zking.util;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
 * 权限工具类
 * @author： 君临沂
 *
 */
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;
  }
}

package com.junlinyi.dao;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import com.junlinyi.entity.Permission;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.zking.util.BaseDao;
import com.zking.util.BuildTree;
import com.zking.util.PageBean;
import com.zking.util.TreeVo;
public class PermissionDao extends BaseDao<Permission>{
  //查询
  public List<Permission> list(Permission permission, PageBean pageBean) throws Exception {
    String sql="select * from t_easyui_permission";
    return super.executeQuery(sql, Permission.class, pageBean);
  }
  //将平级数据转成有父子关系的数据
//  public List<TreeVo<Permission>> menus(Permission permission, PageBean pageBean) throws Exception {
//    List<TreeVo<Permission>> lst=new ArrayList<TreeVo<Permission>>();
//    List<Permission> list = this.list(permission, pageBean);
//    for (Permission p : list) {
//      TreeVo<Permission> treevo=new TreeVo<Permission>();
//      treevo.setId(p.getId()+"");
//      treevo.setText(p.getName());
//      treevo.setParentId(p.getPid()+"");
//      lst.add(treevo);
//    }
//    return BuildTree.buildList(lst, "0");
//    
//  }
  //分好的二级节点和三级节点
    public List<TreeVo<Permission>>  menus(Permission permission, PageBean pageBean) throws Exception {
      List<TreeVo<Permission>> trees = new ArrayList<TreeVo<Permission>>();
      List<Permission> list = this.list(permission, pageBean);
      for (Permission p : list) {
        TreeVo<Permission> vo = new TreeVo<>();
        vo.setId(p.getId()+"");
        vo.setText(p.getName());//节点名称
        vo.setParentId(p.getPid()+"");
        trees.add(vo);
      }
      return BuildTree.buildList(trees,"0");
    }
    public TreeVo<Permission> menu(Permission permission,PageBean pageBean) throws Exception {
      List<TreeVo<Permission>> trees = new ArrayList<TreeVo<Permission>>();
      List<Permission> list = this.list(permission, pageBean);
      for (Permission p : list) {
        TreeVo<Permission> vo = new TreeVo<>();
        vo.setId(p.getId()+"");
        vo.setText(p.getName());//节点名称
        vo.setParentId(p.getPid()+"");
        vo.setChildren(menus(null, null));//将分好的二级节点和三级节点加到顶级节点里
        trees.add(vo);
      }
      return BuildTree.build(trees);
    }
public static void main(String[] args) throws Exception {
   List<TreeVo<Permission>> menus = new PermissionDao().menus(null, null);
  ObjectMapper om = new ObjectMapper();
  System.out.println(om.writeValueAsString(menus));
}
}

package com.junlinyi.web;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.junlinyi.dao.PermissionDao;
import com.junlinyi.entity.Permission;
import com.zking.framework.ActionSupport;
import com.zking.framework.ModelDriver;
import com.zking.util.ResponseUtil;
import com.zking.util.TreeVo;
public class PermissionAction extends ActionSupport implements ModelDriver<Permission>{
  private Permission p=new Permission();
  private PermissionDao pd=new PermissionDao();
  public void menu(HttpServletRequest req, HttpServletResponse resp) throws Exception {
//    List<TreeVo<Permission>> menus = pd.menus(null, null);
//    ResponseUtil.writeJson(resp, menus);
    TreeVo<Permission> menu2 = pd.menu(null, null);//调用顶级节点方法
    //向前端响应树形结构的数据
    ResponseUtil.writeJson(resp, menu2);//转为json格式
  }
  @Override
  public Permission getModel() {
    return p;
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<config>
  <!-- <action path="/blog" type="com.zking.web.BlogAction">
    <forward name="list" path="/blogList.jsp" redirect="false" />
    <forward name="toList" path="/blog.action?methodName=list"
      redirect="true" />
    <forward name="toEdit" path="/blogEdit.jsp" redirect="false" />
  </action> -->
  <action path="/user" type="com.junlinyi.web.UserAction">
  </action>
    <action path="/permission" type="com.junlinyi.web.PermissionAction">
  </action>
</config>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@ include file="common/header.jsp" %>
<!DOCTYPE html >
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</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="static/images/bg.jpg" class="layui-nav-img">
          个人中心
        </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">
      </ul>
    </div>
  </div>
  <div class="layui-body">
    <!-- 内容主体区域 -->
    <div style="padding: 15px;">内容主体区域。</div>
  </div>
  <div class="layui-footer">
    <!-- 底部固定区域 -->
            底部固定区域
  </div>
</div>
<script type="text/javascript">
/* 三级菜单 */
 layui.use(['jquery'], function(){
  let $ = layui.jquery;
  $.ajax({
    url:'${pageContext.request.contextPath }/permission.action?methodName=menu',
    dataType:'json',
    success:function(data){
      console.log(data);
      let str='';
      str +='<li class="layui-nav-item layui-nav-itemed">';
      str +='<a class="" href="javascript:;">'+data.text+'</a>';//顶级节点
      //判断节点是否存在子节点
      if(!data.hasChildren){
        str +='<dl class="layui-nav-child">';
          let children = data.children;
          $.each(children,function(index,node){//二级节点
            str +='<dd><a href="javascript:;">'+children[index].text+'</a></dd>';
            if(!data.hasChildren){
              str +='<dl class="layui-nav-child">';
              let children2 =children[index].children;
              $.each(children2,function(index,node){//三级节点
                str +='<dd><a href="javascript:;">'+children2[index].text+'</a></dd>';
              });
              str +='</dl>';
            }
          });
          str +='</dl>';
      }
      str +='</li>';
    $("#menu").html(str);//渲染
    }
  });
 });
</script>
</body>
</html>