vue+ java 实现多级菜单递归效果

效果如图：

大概思路：树形视图使用的是vue官方事例代码，java负责封装数据，按照vue官方事例的数据结构封装数据即可。有两个需要关注的点：

1.官方事例的数据结构是一个对象里面包含着集合，而不是一个集合对象 2.递归算法

上代码：

前端：html+js

<html>
 <head>
 <meta charset="UTF-8">
 <title></title>
 <script src="https://cdn.jsdelivr.net/npm/vue@2.6.9/dist/vue.js"></script>
 <!-- 引入样式 -->
 <link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css" rel="external nofollow" >
 <!-- 引入组件库 -->
 <script src="https://unpkg.com/element-ui/lib/index.js"></script>
 <script src="https://unpkg.com/axios/dist/axios.min.js"></script>
 <script src="${ctx}/core-plugins/ew/depend/jquery/jquery.min.js" type="text/javascript"></script>
<style>
 body {
 font-family: Menlo, Consolas, monospace;
 color: #444;
}
.item {
 cursor: pointer;
}
.bold {
 font-weight: bold;
}
ul {
 padding-left: 1em;
 line-height: 1.5em;
 list-style-type: dot;
}
</style>
<script type="text/x-template" id="item-template">
 <li>
 <div :class="{bold: isFolder}" @click="toggle" @dblclick="makeFolder">
  {{ item.name }}
 
  <span v-if="isFolder">[{{ isOpen ? '-' : '+' }}]</span>
 </div>
 <ul v-show="isOpen" v-if="isFolder">
  <tree-item
  class="item"
  v-for="(child, index) in item.children"
  :key="index"
  :item="child"
  @make-folder="$emit('make-folder', $event)"
  @add-item="$emit('add-item', $event)"
  ></tree-item>
  <li class="add" @click="$emit('add-item', item)">+</li>
 </ul>
 </li>
</script>
</head>
<body>
 
 <div id="demo">
 <ul >
 <tree-item class="item" :item="treeData" @make-folder="makeFolder" @add-item="addItem"> </tree-item>
 </ul>
 </div>
</body>
</html>
<script>
 Vue.component('tree-item', {
 template: '#item-template',
 props: {
  item: Object 
 },
 data: function () {
  return {
  isOpen: false
  }
 },
 computed: {
  isFolder: function () {
  return this.item.children &&
   this.item.children.length
  }
 },
 methods: {
  toggle: function () {
  if (this.isFolder) {
   this.isOpen = !this.isOpen
  };
  },
  makeFolder: function () {
  if (!this.isFolder) {
   this.$emit('make-folder', this.item)
   this.isOpen = true
  }
  }
 }
 })
 var demo = new Vue({
 el: '#demo',
 data: {
  treeData: {}
 },
 methods: {
  makeFolder: function (item) {
  Vue.set(item, 'children', [])
  this.addItem(item)
  },
  addItem: function (item) {
  item.children.push({
   name: 'new stuff'
  })
  },
  searchData:function(){
  debugger;
 axios.get('menuRoleLimitBLH_searchMenus.do?pageType=1')
 .then(response => (
  this.treeData = response.data.json.menuMaps
  ))
 .catch(error => console.log(error));
 }
 },
 created() {
 this.searchData();
  },
 
 
 })
</script>

后台：java +mysql，一共三个方法，分别是：1.获取请求 2获取所有菜单 3递归菜单的父子关系

/**
 * Purpose:菜单列表页面
 * @author JaxWan
 * @param req
 * @return IZrarResponse
 */
 public IZrarResponse searchMenus(IZrarRequest req){
 IZrarResponse res = new ZrarResponse();
 String pageType = req.getParameter("pageType");
 if(StringUtil.isNotNull(pageType)){
 List<EwTreeVO> EwTreeVOs = dao.selectList("selectAllMenuTree");
 List<Map<String, Object>> menus = this.getMenusList(EwTreeVOs);
 Map<String, Object> map = new HashMap<String, Object>();
 map.put("id", 1);
 map.put("name", 2);
 map.put("children", menus);
 res.addJson("menuMaps", map);
 }else {
 res.addPage("pages/ewsys/dept/menu_role_limit.jsp").addJSTL("isExtForm", false).addJSTL("isEmptyForm", false);
 }
 return res;
 }
/**
 * Purpose:获取菜单集合
 * @author JaxWan
 * @param EwTreeVOs
 * @return List<Map<String,Object>>
 */
 public List<Map<String, Object>> getMenusList(List<EwTreeVO> EwTreeVOs){
 List<Map<String, Object>> menus = new ArrayList<Map<String,Object>>();
 for (int i = 0; i < EwTreeVOs.size(); i++) {
 EwTreeVO ewTreeVO = EwTreeVOs.get(i);
 String id = ewTreeVO.getId();
 String name = ewTreeVO.getName();
 String pId = ewTreeVO.getpId();
 Map<String, Object> map = new HashMap<String, Object>();
 map.put("id", id);
 map.put("name", name);
 map.put("pId", pId);
 Map<String, Object> map2 = this.digui(id, EwTreeVOs,map);
 menus.add(map2);
 }
 return menus;
 }
 
 /**
 * Purpose:递归父子关系
 * @author JaxWan
 * @param id 父节点id
 * @param EwTreeVOs2 菜单集合
 * @param mapResult 结果集
 * @param lists 孩子集合
 * @return Map<String,Object>
 */
 public Map<String, Object> digui(String id,List<EwTreeVO> EwTreeVOs2,Map<String, Object> mapResult){
 List<Map<String, Object>> lists = new ArrayList<Map<String,Object>>();
 for (int j = 0; j < EwTreeVOs2.size(); j++) {
 EwTreeVO ewTreeVO2 = EwTreeVOs2.get(j);
 String id2 = ewTreeVO2.getId();
 String name2 = ewTreeVO2.getName();
 String pId2 = ewTreeVO2.getpId();
 if(id.equals(pId2)){
 Map<String, Object> map2 = new HashMap<String, Object>();
 map2.put("id", id2);
 map2.put("name", name2);
 map2.put("pId", pId2);
 lists.add(map2);
 EwTreeVOs2.remove(j);
 j--;
 }
 }
 mapResult.put("children", lists);
 for (int i = 0; i < lists.size(); i++) {
 Map<String , Object> tempMap = lists.get(i);
 String id1 = (String) tempMap.get("id");
 this.digui(id1,EwTreeVOs2,tempMap);
 }
 return mapResult;
 }

总结

以上所述是小编给大家介绍的vue+ java 实现多级菜单递归效果，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对呐喊教程网站的支持！
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