跨域1
<body>
<input type="text" name="uname" id="uname"/>
<input type="button" value="提交" id="button"/>
</body>
<script type="text/javascript" src="js/jquery-1.8.3.min.js"></script>
<script>
$(function(){
/*$("#button").click(function(){
var uname=$("#uname").val();
$.ajax({
url:"http://www.a.cn:8080/A",
type:"POST",
data:{"uname":uname},
success:function(result){
alert(result)
},
srror:function(){
alert('错');
}
})
})*/
$("#button").click(function(){
var uname=$("#uname").val();
$.ajax({
url:"http://www.a.cn:8080/A?uname="+uname,
type:"GET",
jsonp:"jsonpCallBack",
dataType:"JSONP",
success:function(result){
alert(result)
},
srror:function(){
alert('错');
}
})
})
/*$("#button").click(function(){
var uname=$("#uname").val();
$.ajax({
url:"BServlet?uname="+uname,
type:"GET",
success:function(result){
alert(result)
},
srror:function(){
alert('错');
}
})
})*/
})
</script>
@WebServlet("/A")
public class AServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//接收内容
String uname = req.getParameter("uname");
System.out.println("接收到的："+uname);
//接受ajax数据
String back = req.getParameter("jsonpCallBack");
System.out.println("jsonpCallBack"+back);
String meiChuanKuZi = (String)JSON.toJSONString("MeiChuanKuZi");
//响应结果
resp.getWriter().write(back+"("+meiChuanKuZi+")");
/*resp.getWriter().write("meiChuanKuZi");*/
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
/*//接收内容
String uname = req.getParameter("uname");
System.out.println("接收到的："+uname);
*//*
//设置请求头
resp.setHeader("Access-Control-Allow-Origin","*");
*//*
//接受ajax数据
String back = req.getParameter("jsonpCallBack");
System.out.println("jsonpCallBack"+back);
String meiChuanKuZi = (String)JSON.toJSONString("MeiChuanKuZi");
//响应结果
resp.getWriter().write(back+"("+meiChuanKuZi+")");*/
}
}
表单重复提交
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script src="js/jquery-1.8.3.min.js"></script>
<script type="text/javascript">
var flag=false;
function fromSubmit(){
if(!flag){
flag=true;
return true;
}else{
return false;
}
}
$(function(){
$.ajax({
url:"ToKenServlet",
type:"POST",
success:function(token){
$("#hiddenToken").val(token);
}
})
})
</script>
</head>
<body>
<form action="FromServlet" onsubmit="return fromSubmit()" method="post">
<input type="text" name="uname" id="uname"/>
<input type="hidden" id="hiddenToken" name="formToken"/>
<input type="submit" value="提交"/>
</form>
</body>
</html>
@WebServlet("/FromServlet")
public class FromServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");
System.out.println("进了FromServlet");
//提取
String formToken = req.getParameter("formToken");
//获取会话中的
String sessionToken = (String)req.getSession().getAttribute("sessionToken");
//判断
if (!formToken.equals(sessionToken)){
resp.getWriter().write("您已重复提交！！！");
return;
}
//接收内容
String uname = req.getParameter("uname");
System.out.println("接收到的："+uname);
req.getSession().removeAttribute("sessionToken");
resp.getWriter().write("meiChuanKuZi");
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
@WebServlet("/ToKenServlet")
public class ToKenServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
System.out.println("进了ToKenServlet");
//生成令牌
String token= UUID.randomUUID().toString();
//保存
req.getSession().setAttribute("sessionToken",token);
//响应
resp.getWriter().write(token);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}