一.json常用转换方法

1.list

1List list = new ArrayList();
2list.add("first");
3list.add("second");
4JSONArray jsonArray2 = JSONArray.fromObject(list);

2.map

1Map map = new HashMap();
2map.put("name", "json");
3map.put("bool", Boolean.TRUE);
4map.put("int", new Integer(1));
5map.put("arr", new String[] { "a", "b" });
6map.put("func", "function(i){ return this.arr[i]; }");
7JSONObject json = JSONObject.fromObject(map);

3.bean

JSONObject jsonObject = JSONObject.fromObject(new JsonBean());

4.数组

1boolean[] boolArray = new boolean[] { true, false, true }; 
2JSONArray jsonArray1 = JSONArray.fromObject(boolArray);

5.一般数据

JSONArray jsonArray3 = JSONArray.fromObject("['json','is','easy']" );

6.beans

1List list = new ArrayList();
2JsonBean2 jb1 = new JsonBean2();
3jb1.setCol(1);
4jb1.setRow(1);
5jb1.setValue("xx");
6JsonBean2 jb2 = new JsonBean2();
7jb2.setCol(2);
8jb2.setRow(2);
9jb2.setValue("");
10list.add(jb1);
11list.add(jb2);
12JSONArray ja = JSONArray.fromObject(list);

二.HTML页面将String转换成json

eval()

1function testFunction() {
2	var jsonStr = '${str}';
3	var dataObj = eval("(" + jsonStr + ")");//转换为json对象
4	$.each(dataObj.info, function(idx, item) {
5		alert("name:" + item.uuid + " , vaddress:" + item.vaddress);
6	});
7}

三.后台向前台传json

1.使用转义符  \

2.交给前台来处理 eval()

3.使用json工具类

后台代码:

1        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
2		//1.返回标准的json字符串(双引号要用转义符)
3		//String s = "[{\"id\":1,\"text\":\"Root node\",\"children\":[{\"id\":2,\"text\":\"Child node 1\",\"children\":true},{\"id\":3,\"text\":\"Child node 2\"}]}]";
4		
5		//2.前台使用eval()函数将string装换成json格式
6		//String s = "[{id:1,text:'Root node',children:[{id:2,text:'Child node 1',children:true},{id:3,text:'Child node 2'}]}]";
7		
8		//3.使用json工具类
9		JSONArray s = getJson();
10		response.setContentType("json");
11		
12		response.getWriter().print(s);
13	}
14
15        private JSONArray getJson() {
16		JSONObject jo1 = new JSONObject();
17		JSONObject jo2 = new JSONObject();
18		jo1.put("id", 2);
19		jo1.put("text", "Child node 1");
20		jo2.put("id", 3);
21		jo2.put("text", "Child node 2");
22		JSONArray jsonArray = new JSONArray();
23		jsonArray.add(jo1);
24		jsonArray.add(jo2);
25		JSONObject jsonObject = new JSONObject();
26		jsonObject.put("id", 1);
27		jsonObject.put("text", "Root node");
28		jsonObject.put("children", jsonArray);
29		JSONArray json = new JSONArray();
30		json.add(jsonObject);
31		return json;
32	}

前台代码:

1<div id="jstree"></div>
2	<script>
3		$(function() {
4			$.ajax({
5				url : "IndexServlet",
6				datatype : "json",
7				success : function(o) {
8					create(o);
9				}
10			});
11		});
12		function create(data) {
13			//data = eval("(" + data + ")");
14			$('#jstree').jstree({
15				"core" : {
16					"data" : data
17				},
18			});
19		}
20		/* $(function() {
21			$('#jstree').jstree({
22				'core' : {
23					'data' : {
24						"url" : "IndexServlet",
25						"data" : function(node) {
26							return {
27								"id" : node.id
28							};
29						},
30					    "dataFilter" : function(o) {
31							o = eval("(" + o + ")");
32							console.info(o);
33							return o;
34						} 
35					}
36				}
37			});
38		}); */
39	</script>