防止表单重复提交的方法-javascript与session

来源：互联网发布：java 面试threadlocal 编辑：程序博客网时间：2024/05/25 12:20

Servlet:

package Session;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class FormServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);

}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Date data = new Date();
String token = data.getTime() + "";
System.out.println(token);
request.getSession().setAttribute("token", token);
request.getRequestDispatcher("index.jsp").forward(request, response);
}
}

package Session;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class HandleFormServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
boolean b = isRepeatSubmit(request);
if (b == true) {
System.out.println("请不要重复提交");
}
request.getSession().removeAttribute("token");
System.out.println("处理提交请求");
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
request.getRequestDispatcher("home.jsp").forward(request, response);

}

public boolean isRepeatSubmit(HttpServletRequest request) {
// 1.如果用户提交的表单中token为空，则用户重复提交了表单
String client_token = request.getParameter("token");
if (client_token == null) {
return true;
}
// 取出session中的token
String server_token = (String) request.getSession().getAttribute(
"token");
// 如果当前用户session不存在，则用户重复提交表单
if (server_token == null) {
return true;
}
// 用户表单提交的token值与存储在session中的token值不同，则用户重复提交表单
if (!client_token.equals(server_token)) {
return true;
}
return false;
}
}

JSP页面：

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="c"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<form action="HandleFormServlet" onsubmit="isSubmit()"
method="post">
<input type="hidden" name="token" value="${token}"> 请输入姓名：<input
type="text" name="userName"><br> <input type="submit"
value="提交" id="submit">
</form>
</body>
<script type="text/javascript">
var issubmit = false;//表单是否已经提交标识，默认为false
function handlesubmit(){
//alert("safsdf");
if (issumit == false) {
alert("处理请求中");
issumit = true;//提交表单后，将表单是否已经提交标识设置为true
return true;//返回true,让表单提交
} else {
return false;//返回false，让表单不能提交
alert("请不要重复提交！");
}

}
</script>
</html>

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