简单的ajax获取json - JAVA

一个DBhelper类，用来操作数据库

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Configuration;

using System.Data;

using System.Data.SqlClient;

namespace JsonTest.helper

{

public class DBhelper

{

public static string ConnectStrings;

public static void GetConnectStr()

{

ConnectStrings = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionStr"].ConnectionString;

}

public static SqlDataReader GetCommentByID(int id,string sql)

{

GetConnectStr();

SqlDataReader rs = null;

try

{

SqlConnection con = new SqlConnection(ConnectStrings);

con.Open();

SqlCommand com = new SqlCommand(sql, con);

rs=com.ExecuteReader();

}

catch (Exception err)

{

throw err;

}

return rs;

}

};

前台htm页发出ajax post请求

$(document).ready(function () {

$("#button1").click(function sys() {

$.post("html_1.ashx", { "ID": 1 }, function sys(json) {

var str = json.item1 + json.item2 + json.item3 + json.item4;

$("ul").append("

" + str + "

");

}, "json");

});

后台ashx处理程序处理请求

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Data;

using System.Data.SqlClient;

using JsonTest.helper;

using System.Web.Script.Serialization;

namespace JsonTest

{

///

/// html_1 的摘要说明

///

public class html_1 : IHttpHandler

{

public void ProcessRequest(HttpContext context)

{

context.Response.ContentType = "text/plain";

int id = Convert.ToInt32(context.Request["ID"]);

string sql = "select * from item where ItemID=" + id + "";

SqlDataReader sdr = null;

sdr=DBhelper.GetCommentByID(id, sql);

item Item = new item();

while (sdr.Read())

{

Item.item1 = sdr[0].ToString();

Item.item2 = sdr[1].ToString();

Item.item3 = sdr[2].ToString();

Item.item4 = sdr[3].ToString();

}

sdr.Close();

sdr = null;

JavaScriptSerializer js = new java scriptSerializer();

string json = js.Serialize(Item).ToString();

context.Response.Write(json);

}

public bool IsReusable

{

get

{

return false;

}

public class item

{

public string item1;

public string item2;

public string item3;

public string item4;

}

这样就可以无刷新的实现