Service层：
@Service
public class ItemCatServiceImpl implements ItemCatService {

	@Autowired
	private TbItemCatMapper itemCatMapper;
	
	@Override
	public List<EasyUITreeNode> getItemCatList(long parentId) {
		// 根据parentId查询分类列表
		TbItemCatExample example = new TbItemCatExample();
		//设置查询条件
		Criteria criteria = example.createCriteria();
		criteria.andParentIdEqualTo(parentId);
		//执行查询
		List<TbItemCat> list = itemCatMapper.selectByExample(example);
		//转换成EasyUITreeNode列表
		List<EasyUITreeNode> resultList = new ArrayList<>();
		for (TbItemCat tbItemCat : list) {
			//创建一个节点对象
			EasyUITreeNode node = new EasyUITreeNode();
			node.setId(tbItemCat.getId());
			node.setText(tbItemCat.getName());
			node.setState(tbItemCat.getIsParent()?"closed":"open");
			//添加到列表中
			resultList.add(node);
		}
		return resultList;
	}

}


Controller层：
@Controller
@RequestMapping("/item/cat")
public class ItemCatController {

	@Autowired
	private ItemCatService itemCatService;
	
	@RequestMapping("/list")
	@ResponseBody
	public List<EasyUITreeNode> getItemCatList(@RequestParam(value="id", defaultValue="0")Long parentId) {
		List<EasyUITreeNode> list = itemCatService.getItemCatList(parentId);
		return list;
	}
	
}

JS：显示异步tree：
  initItemCat : function(data){
    	$(".selectItemCat").each(function(i,e){
    		var _ele = $(e);
    		if(data && data.cid){
    			_ele.after("<span style='margin-left:10px;'>"+data.cid+"</span>");
    		}else{
    			_ele.after("<span style='margin-left:10px;'></span>");
    		}
    		_ele.unbind('click').click(function(){
    			$("<div>").css({padding:"5px"}).html("<ul>")
    			.window({
    				width:'500',
    			    height:"450",
    			    modal:true,
    			    closed:true,
    			    iconCls:'icon-save',
    			    title:'选择类目',
    			    onOpen : function(){
    			    	var _win = this;
    			    	$("ul",_win).tree({
    			    		url:'/item/cat/list',
    			    		animate:true,
    			    		onClick : function(node){
    			    			if($(this).tree("isLeaf",node.target)){
    			    				// 填写到cid中
    			    				_ele.parent().find("[name=cid]").val(node.id);
    			    				_ele.next().text(node.text).attr("cid",node.id);
    			    				$(_win).window('close');
    			    				if(data && data.fun){
    			    					data.fun.call(this,node);
    			    				}
    			    			}
    			    		}
    			    	});
    			    },
    			    onClose : function(){
    			    	$(this).window("destroy");
    			    }
    			}).window('open');
    		});
    	});
    },

jsp:
<a href="javascript:void(0)" class="easyui-linkbutton selectItemCat">选择类目</a>