什么是表单重复提交:由于网速问题,用户不端点击提交按钮,或者刷新页面。或,已经提交成功,用户点击后退,然后恶意刷新页面形成重复提交的问题。
一)、令牌机制:
在struts2中使用令牌机制,解决重复提交问题:原理:产生一个随机字符串,在客户端和服务端同时保留此字符串的副本,在客户端想服务的发送请求的过程中,会自动发送此副本,服务端收到请求后,会判断本地令牌和提交的令牌是否一致,如果相同,则执行提交动作,完成数据库等等的业务逻辑操作,完成之后,服务器端的副本会立即参数一个新的令牌,而客户端不变;如果客服端在提交,因令牌不同,则判定为重复提交。
二)、使用struts2防止表单重复提交:
在jsp表单中加入指令
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib uri = "/struts-tags" prefix = "s"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'login.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<form action="default.action" method = "post">
<s:token/>
姓名: <input name = "name" type = "text"><br><br>
密码: <input name = "password" type ="password"><br><br>
<input type = "submit" value = "登陆">
</form>
</body>
</html>
配置文件:主要是将token拦截器配置到默认拦截器中
<package name = "default" namespace = "/" extends = "struts-default">
<interceptors>
<interceptor-stack name="myStack">
<interceptor-ref name="token"/>
<interceptor-ref name="defaultStack"/>
</interceptor-stack>
</interceptors>
<default-interceptor-ref name="myStack"/>
<action name = "login" class ="com.action.LoginAction">
<result name = "success" >/login.jsp</result>
</action>
<action name = "default" class ="com.action.DefaultAction">
<result name = "success" >/index.jsp</result>
<result name = "invalid.token">/505.jsp</result>
</action>
</package>
使用tokenSession标签:
struts.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts>
<package name="default" namespace = "/" extends = "struts-default">
<action name="login" class = "com.action.LoginAction">
<interceptor-ref name="tokenSession"/>
<interceptor-ref name="defaultStack"/>
<result>/ok.jsp</result>
</action>
</package>
</struts>
LoginAction:
package com.action;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport{
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String execute() {
return SUCCESS;
}
}