Java 如何在servlet中读取ajax发送的json
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How to read json sent by ajax in servlet
提问by Yosua Sofyan
I'm new to java and I struggling with this problem for 2 days and finally decided to ask here.
我是 Java 新手，我在这个问题上苦苦挣扎了 2 天，最后决定在这里提问。
I am trying to read data sent by jQuery so i can use it in my servlet
我正在尝试读取 jQuery 发送的数据，以便我可以在我的 servlet 中使用它
jQuery
jQuery
var test = [
{pv: 1000, bv: 2000, mp: 3000, cp: 5000},
{pv: 2500, bv: 3500, mp: 2000, cp: 4444}
];
$.ajax({
type: 'post',
url: 'masterpaket',
dataType: 'JSON',
data: 'loadProds=1&'+test, //NB: request.getParameter("loadProds") only return 1, i need to read value of var test
success: function(data) {
},
error: function(data) {
alert('fail');
}
});
Servlet
小服务程序
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
if (request.getParameter("loadProds") != null) {
//how do i can get the value of pv, bv, mp ,cp
}
}
I really appreciate any help you can provide.
我非常感谢您能提供的任何帮助。
采纳答案by siledh
You won't be able to parse it on the server unless you send it properly:
除非您正确发送，否则您将无法在服务器上解析它：
$.ajax({
type: 'get', // it's easier to read GET request parameters
url: 'masterpaket',
dataType: 'JSON',
data: {
loadProds: 1,
test: JSON.stringify(test) // look here!
},
success: function(data) {
},
error: function(data) {
alert('fail');
}
});
You must use JSON.stringifyto send your JavaScript object as JSON string.
您必须使用JSON.stringify将您的 JavaScript 对象作为 JSON 字符串发送。
And then on the server:
然后在服务器上：
String json = request.getParameter("test");
You can parse the jsonstring by hand, or using any library (I would recommend gson).
您可以json手动解析字符串，也可以使用任何库（我推荐gson）。
回答by Rakesh Soni
You will have to use the JSON parser to parse the data into the Servlet
您将不得不使用 JSON 解析器将数据解析到 Servlet
import org.json.simple.JSONObject;
// this parses the json
JSONObject jObj = new JSONObject(request.getParameter("loadProds"));
Iterator it = jObj.keys(); //gets all the keys
while(it.hasNext())
{
String key = it.next(); // get key
Object o = jObj.get(key); // get value
System.out.println(key + " : " + o); // print the key and value
}
You will need a json library (e.g Hymanson) to parse the json
您将需要一个 json 库（例如 Hymanson）来解析 json
回答by hlopezvg
Using the import org.json.JSONObject instead of import org.json.simple.JSONObject did the trick for me.
使用 import org.json.JSONObject 而不是 import org.json.simple.JSONObject 对我有用。
See How to create Json object from String containing characters like ':' ,'[' and ']' in Java.
