Json全名:JavaScriprt Objet Notation 是一种简单的数据格式比XML更轻巧..Json是JavaScript 的原生格式...所以在JavaScript中处理Json数据不需要任何特殊的API及JAR...
Json规则:对象是一个无序的 " ' 名称/值 ' 对 " 集合,一个对象以 " {" ( 左括号)开始"}" (右括号) 结束。每个 " 名称 " 后跟一个 " : "( 冒号) ; " '名称/值 ' 对 " 之间使用 " , "(逗号)分隔。
Examples:
1. function showJSON() { var user = { "username":"qinrw", "age":24, "info": { "tel": "188029xxxxx", "cellphone" : "98765"}, "address": [ {"city":"陕西","postcode" : "0823"}, {"city":"北京","postcode" :" 0823"} ] } alert(user.username); alert(user.age); alert(user.info.cellphone); alert(user.address[0].city); alert(user.address[0].postcode); }
2.JSON来简单的修改数据
function showJSON() {
var user = {
"username":"qinrw",
"age":24,
"info": { "tel": "123456", "cellphone": "98765"},
"address": [
{"city":"陕西","postcode":"0823"},
{"city":"北京","postcode":"0823"}
]
}
alert(user.username);
alert(user.age);
alert(user.info.cellphone);
alert(user.address[0].city);
alert(user.address[0].postcode);
user.username = "imqinrw";
alert(user.username);
}
3.JSON提供了json.js包,下载http://www.json.org/json.js后,将其引入然后就可以简单的使用object.toJSONString()转换成JSON数据。
function showCar() {
var carr = new Car("Dodge", "Coronet R/T", 1968, "yellow");
alert(carr.toJSONString());
}
function Car(make, model, year, color) {
this.make = make;
this.model = model;
this.year = year;
this.color = color;
}
使用eval来转换JSON字符到Object
function myEval() {
var str = '{ "name": "Violet", "occupation": "character" }';
var obj = eval('(' + str + ')');
alert(obj.toJSONString());
}
或者使用parseJSON()方法
function myEval() {
var str = '{ "name": "Violet", "occupation": "character" }';
var obj = str.parseJSON();
alert(obj.toJSONString());
}
JSON还提供了java的jar包 http://www.json.org/java/index.html API也很简单,下面举个例子
*在javascript中填加请求参数
js 代码
function sendRequest() {
var carr = new Car("Dodge", "Coronet R/T", 1968, "yellow");
var pars = "car=" + carr.toJSONString();
var url = "/MyWebApp/JSONTest1";
var mailAjax = new Ajax.Request(
url,
{
method: 'get',
parameters: pars,
onComplete: jsonResponse
}
);
}
使用JSON请求字符串就可以简单的生成JSONObject并进行解析,修改servlet添加JSON的处理(要使用json.jar)
java 代码
private void doService(HttpServletRequest request, HttpServletResponse response) throws IOException {
String s3 = request.getParameter("car");
try {
JSONObject jsonObj = new JSONObject(s3);
System.out.println(jsonObj.getString("model"));
System.out.println(jsonObj.getInt("year"));
} catch (JSONException e) {
e.printStackTrace();
}
response.getWriter().print("{ /"name/": /"Violet/", /"occupation/": /"character/" }");
}
同样可以使用JSONObject生成JSON字符串,修改servlet
java 代码
private void doService(HttpServletRequest request, HttpServletResponse response) throws IOException {
String s3 = request.getParameter("car");
try {
JSONObject jsonObj = new JSONObject(s3);
System.out.println(jsonObj.getString("model"));
System.out.println(jsonObj.getInt("year"));
} catch (JSONException e) {
e.printStackTrace();
}
JSONObject resultJSON = new JSONObject();
try {
resultJSON.append("name", "Violet")
.append("occupation", "developer")
.append("age", new Integer(22));
System.out.println(resultJSON.toString());
} catch (JSONException e) {
e.printStackTrace();
}
response.getWriter().print(resultJSON.toString());
}
js 代码
function jsonResponse(originalRequest) {
alert(originalRequest.responseText);
var myobj = originalRequest.responseText.evalJSON(true);
alert(myobj.name);
alert(myobj.age);
}