java easyui 树型结构查询封装

ゝ一纸荒年。 2022-04-06 02:50 214阅读 0赞

一次数据库查询，封装成树型结构数据 List<TreeNodeVo>

/**
     * 查询所有，返回菜单树
     * @return	List<TreeNodeVo>
     */
    public List<TreeNodeVo> getTreeListAll() {
    	List<Menu> menuList = menuDao.getListAll();
    	List<TreeNodeVo> tempTreeNodeVos = new ArrayList();
    	TreeNodeVo tempTreeNode;
    	for (Menu menu : menuList) {
    		tempTreeNode = new TreeNodeVo();
    		tempTreeNode.setId(menu.getId());
    		tempTreeNode.setParentId(menu.getParentId());
    		tempTreeNode.setText(menu.getName());
    		if ("1".equals(menu.getLeaf())) {
    			tempTreeNode.setState("open");
    		} else {
    			tempTreeNode.setState("closed");
    		}
    		tempTreeNode.setUrl(menu.getUrl());
    		tempTreeNodeVos.add(tempTreeNode);
    	}
    
    	if (tempTreeNodeVos != null) {
    		List<TreeNodeVo> treeNodeVos = new ArrayList();
    		Map<String, TreeNodeVo> map = new LinkedHashMap<String, TreeNodeVo>();
    		for (TreeNodeVo tn : tempTreeNodeVos) {
    			map.put(tn.getId(), tn);
    		}
    
    		TreeNodeVo treeNodeVo;
    		TreeNodeVo pTreeNodeVo;
    		for (String id : map.keySet()) {
    			treeNodeVo = map.get(id);
    			if (treeNodeVo.getParentId() == null) {
    				treeNodeVos.add(treeNodeVo);
    			} else {
    				pTreeNodeVo = map.get(treeNodeVo.getParentId());
    				List<TreeNodeVo> children = pTreeNodeVo.getChildren();
    				if(children!=null){
    					children.add(treeNodeVo);
    				} else {
    					children = new ArrayList();
    					children.add(treeNodeVo);
    					pTreeNodeVo.setChildren(children);
    				}
    			}
    		}
    		return treeNodeVos;
    	}
    	return null;
    }

参考：

easyui tree 树 **TreeNodeVo**

http://happyqing.iteye.com/blog/2371178

将数据封装成树形结构，无限级深，

http://www.oschina.net/code/snippet\_915857\_22297

/**
     *  包装成树形结构 (全部属性)
     *  将数据封装成树形结构，无限级深，只需遍历两次 @param tree为List类型存放的初始VO对象。该vo类必须有id,parentId，children字段。children为List类型
     * @param tree
     * @return
     * @throws Exception
     */
    public static List factorTree(List tree) throws Exception{
    	if (tree != null) {
    		List t_list = new ArrayList();
    		Map map = new HashMap();
    		for (Object o : tree) {
    			Class clazz = o.getClass();
    			Field id = clazz.getDeclaredField("id");
    			if (!id.isAccessible()) {
    				id.setAccessible(true);
    			}
    			Long lId = (Long) id.get(o);
    			map.put(lId, o);
    		}
    
    		for (Object o : map.keySet()) {
    			Long cId = (Long) o;
    			Object obj = map.get(cId);
    			Class clazz = obj.getClass();
    			Field pId = clazz.getDeclaredField("parentId");
    			if (!pId.isAccessible()) {
    				pId.setAccessible(true);
    			}
    			Long id = (Long) pId.get(obj);
    			if (id == null) {
    				t_list.add(obj);
    			} else {
    				Object object = map.get(id);
    				Class clazz1 = object.getClass();
    				Field children = clazz1.getDeclaredField("children");
    				if (!children.isAccessible()) {
    					children.setAccessible(true);
    				}
    				List list = (List) children.get(object);
    				if (CollectionUtils.isEmpty(list)) {
    					list = new ArrayList();
    				}
    				list.add(obj);
    				children.set(object, list);
    			}
    		}
    		return t_list;
    	}
    	return null;
    }