Ajax简单的异步请求以及返回的值获取

JS里面写ajax发送请求到页面，页面返回数据提示结果：

--------------------------------------------------JS代码----------------------------------------------------

function trimRepID(s){return s.replace(/^\s+|\s+$/g,"");} //去点字符串的空格的函数

---encodeURI();//UTF-8编码的转换

//先声明一个异步请求对象
var xmlHttpReg = null;

if (window.ActiveXObject) {
//如果是IE
xmlHttpReg = new ActiveXObject("Microsoft.XMLHTTP");
} else if (window.XMLHttpRequest) {
xmlHttpReg = new XMLHttpRequest();
//实例化一个xmlHttpReg
}
//发送请求 方式、路径、权限
xmlHttpReg.open("POST","http://******.jsp?DDD="+repId, true);
//设置头部信息，让它用utf-8发送，不然中文可能会乱码
xmlHttpReg.setrequestheader("content-type","application/x-www-form-urlencoded");
xmlHttpReg.onreadystatechange = function ()
{
if (xmlHttpReg.readyState == 4 && xmlHttpReg.status == 200)
{ }
else{}
}
xmlHttpReg.send(null);
alert("JSOn");//
var flags=xmlHttpReg.responseText;
alert(flags);//返回结果的responseText
var flagf=JSON.stringify(flags);
alert(flagf);//OBJECT转化成STRING
if(flagf.indexOf("tu")>0){alert(" SUCCESSFULLY");} //对结果进行搜索结果，匹配返回值的位置，有即表示成功吗，无就是失败
else{alert("FAILED TO SAVE");}
}

 

 

---------------jsp操作数据代码------------------------------------

<script>

window.onload=

function () {
alert("IDBC BE");
<%
System.out.println("Connections");
//获取AJAX传递过来的参数
String operID= request.getParameter("operID");
System.out.println(operID);
response.setContentType("text/html");
PrintWriter outa = response.getWriter();
if(operID!=null){
try {
Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
String url = "jdbc:oracle:thin:@***:**:**";
//orcl为你的数据库的SID
String user = "***";
String password = "***";
//用户名和密码
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement
(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
//建立链接
String sql = "";

//插入数据库的语句
ResultSet rs = stmt.executeQuery(sql);
String result="tu";
rs.close();
stmt.close();
conn.close();
System.out.println(result);
outa.print(result);

} catch (Exception e) {
//返回异常信息
e.printStackTrace();
String result="fa";
outa.print(result);
}}
%>
}
</script>

 

--------------------------jsp代码写在了js中-----------

返回成功----tu   失败---fa