递归无限级树下拉菜单

Java代码  

1. /**  
2.   *树形菜单VO  
3.   */  
4.  public class SelectTree implements Serializable{   
5.     private int id;   
6.     private String name;   
7.     private List<SelectTree> child = new ArrayList<SelectTree>();   
8.                //getter & setter ....略   
9. }  

	/**
	  *树形菜单VO
	  */
	public class SelectTree implements Serializable{
		private int id;
		private String name;
		private List<SelectTree> child = new ArrayList<SelectTree>();
                //getter & setter ....略
	}

代码片段：

Java代码  

1. /**  
2.  * 构建树型菜单数据  
3.  */  
4. public List<SelectTree> buildNode(int pid,List<YcChannel> channels){   
5.     List<SelectTree> result = new ArrayList<SelectTree>();   
6.     for(YcChannel chl:channels){   
7.         SelectTree node = new SelectTree();   
8.         if(null != chl.getParentId() && chl.getParentId().equals(pid)){   
9.             node.setId(chl.getChannelId());   
10.             node.setName(chl.getName());   
11.             List<SelectTree> children = buildNode(chl.getChannelId(),channels);   
12.             if(null != children && 0 < children.size()){   
13.                 node.setChild(children);   
14.             }   
15.             result.add(node);    
16.         }   
17.     }   
18.     return result;   
19. }   
20.   
21. public String queryChannelList() {   
22.     ycChannelList = this.channelSer.queryChannelList();   
23.     List<SelectTree> trees = new ArrayList<SelectTree>();   
24.     for(YcChannel yc:ycChannelList){   
25.         if(null == yc.getParentId()){   
26.             SelectTree t = new SelectTree();   
27.             t.setId(yc.getChannelId());   
28.             t.setName(yc.getName());   
29.             t.setChild(buildNode(t.getId(),ycChannelList));   
30.             trees.add(t);   
31.         }   
32.     }   
33.     this.setAjaxData(trees);   
34.     return AJAX_DATA;   
35. }  

	/**
	 * 构建树型菜单数据
	 */
	public List<SelectTree> buildNode(int pid,List<YcChannel> channels){
		List<SelectTree> result = new ArrayList<SelectTree>();
		for(YcChannel chl:channels){
			SelectTree node = new SelectTree();
			if(null != chl.getParentId() && chl.getParentId().equals(pid)){
				node.setId(chl.getChannelId());
				node.setName(chl.getName());
				List<SelectTree> children = buildNode(chl.getChannelId(),channels);
				if(null != children && 0 < children.size()){
					node.setChild(children);
				}
				result.add(node); 
			}
		}
		return result;
	}
	
	public String queryChannelList() {
		ycChannelList = this.channelSer.queryChannelList();
		List<SelectTree> trees = new ArrayList<SelectTree>();
		for(YcChannel yc:ycChannelList){
			if(null == yc.getParentId()){
				SelectTree t = new SelectTree();
				t.setId(yc.getChannelId());
				t.setName(yc.getName());
				t.setChild(buildNode(t.getId(),ycChannelList));
				trees.add(t);
			}
		}
		this.setAjaxData(trees);
		return AJAX_DATA;
	}

前端JS代码:

Js代码  

1.     //recursive tree node   
2.     function buildNode(len,data){   
3.         var prefix = "|";   
4.         for(var i=0;i<len;i++){   
5.             prefix += "-";   
6.         }   
7.         $.each(data,function(i,item){   
8.             if(0 < item.child.length){   
9.                 $('#typeid').append("<option value="+item.id +">" + prefix + item.name + "</option>");   
10.                 buildNode(len+1,item.child);   
11.             }else{   
12.                 $('#typeid').append("<option value="+item.id +">" + prefix + item.name + "</option>");   
13.             }   
14.         });   
15.     }   
16.        
17.     $.ajax({   
18.         url:'${base}/channel/channelAction!queryChannelList.action',   
19.         type:'GET',   
20.         dataType:'json',   
21.         contentType:'application/json',   
22.         success:function(json){   
23.             if(json.success){   
24.                 $('#typeid').empty();   
25.                 $('#typeid').append("<option value='0'>请选择栏目...</option>");   
26.                 $.each(json.data,function(i,item){   
27.                     if(null == item.parentId){   
28.                         $('#typeid').append("<option value="+item.id +">" + item.name + "</option>");   
29.                         buildNode(1,item.child);   
30.                     }   
31.                 });   
32.             }   
33.         },   
34.         error:function(){   
35.             alert("加载栏目出错!");   
36.         }   
37.     });   
38.        
39. });