Foreground Jquery+ajax+json value, after the background processing to return the JSON string, how to take the property value inside? (No SPRINGMVC annotations)

I. Taking a property value

Front page:

function Select (ID) {
Alert ("HFDFHDFH" +id);
$.ajax ({
URL: "Selectbyid.jsp",
datatype: ' JSON ',
Data:{id:id},//Send data
Error:function (data) {
Alert ("Wrong, no this student!! ");
},
Success:function (data) {
alert (data);
var json = eval ("(" +data+ ")");//Convert JSON type string to JSON object
Alert ("HJF" +json.name);
$ ("#id"). Val (json.id),
$ ("#name"). Val (Json.name),
$ ("#age"). Val (Json.age);
IfJson.sex= = ' man ') {
$ ("Input:radio[name= ' sex ']"). EQ (0). attr ("Checked", true);
$ ("input[name=sex]"). attr ("Checked", "checked");
$ ("#sex"). attr ("Checked", ' checked ');
$ ("#sex"). Removeattr ("checked");
}else{
$ ("Input:radio[name= ' sex ']"). EQ (1). attr ("Checked", true);
$ ("input[name=sex]"). attr ("Checked", "checked");
$ ("#sex"). attr ("Checked", ' checked ');
$ ("#sex"). Removeattr ("checked");
}
}

Background code:

<%@ page language= "java" import= "Java.util.*,com.dao.*,com.bean.*,com.fasterxml.jackson.databind.objectmapper" pageencoding= "Utf-8"%>
<%
int id = integer.parseint (request.getparameter ("id"));
Studentdao dao = new Studentdao ();
Studentbean Bean = Dao.selectbyid (ID);
if (bean!=null) {
Objectmapper x = new Objectmapper ();
String str = x.writevalueasstring (bean); To convert a Java class object to a JSON string
System.out.print (str);
response.getwriter (). print (str); Returning data to the foreground Ajax
}
%>

Two. Front-end Ajax does not receive JSON values what's going on?

Front page:

function Ajaxpost () {
$.ajax ({
data:{"Name": $ ("#name"). Val (),
"Age": $ ("#age"). Val (),
"Sex": $ ("input[name= ' Sex ']:checked"). Val ()},
Type: "Post",
Async:false,//Plus this attribute is good.
DataType: ' JSON ',
URL: "Addstudent.jsp",
Error:function (data) {
Alert (' Add failed! ‘);
},
Success:function (data) {
Alert (' Add success! ‘);
window.location.href = ' list.jsp '
}
});
}

Background code:

<%@ page language= "java" import= "java.util.*,com.dao.*,com.bean.*" pageencoding= "Utf-8"%>
<%
String name = Request.getparameter ("name");
int age = Integer.parseint (Request.getparameter ("Age"));
String sex = request.getparameter ("Sex");
Studentbean student = new Studentbean ();
Student.setname (name);
Student.setage (age);
Student.setsex (Sex);
Studentdao dao = new Studentdao ();
int rows = dao.addstudent (student);
if (rows>0) {
response.getwriter (). Print ("{}");
}
%>

Three. The background query database returns the collection, and the foreground is displayed in the table.

Front page:

$ (document). Ready (function () {
$ ("#list4"). Jqgrid ({//jqgrid Table control
URL: "Selectstudent.jsp",
DataType: "JSON",
Mtype: "POST",
height:600,
PostData: "{searchsql: '}",
Autowidth:true,
colnames:[' ID ', ' name ', ' age ', ' gender ',
colmodel:[
{name: ' id ', index: ' id ', hidden:true},
{name: ' name ', index: ' Name '},
{name: ' Age ', Index: ' Age '},
{name: ' Sex ', index: ' Sex '},

],
Rownumbers:true,
Viewrecords:true,
jsonreader:{
ID: "Blackid",
Repeatitems:false
},
pager:$ (' #gridPager ')
});
});

Background code:

<%@ page language= "java" import= "Java.util.*,com.dao.*,com.bean.*,com.fasterxml.jackson.databind.objectmapper" pageencoding= "Utf-8"%>
<%
Studentdao dao = new Studentdao ();
list<studentbean> list = Dao.selectall ();
if (list!=null) {
Objectmapper x = new Objectmapper ();
String str1 = x.writevalueasstring (list); Collection to JSON type string
Response.getwriter (). print (STR1); Back to front end Ajax
}
%>

Foreground Jquery+ajax+json value, after the background processing to return the JSON string, how to take the property value inside? (No SPRINGMVC annotations)