防止表单重复提交

来源：互联网发布：传智播客大数据第三期编辑：程序博客网时间：2024/06/10 09:40

一，新建一个注解，标注需要防止重复提交的表单方法

/**

* 防止重复提交的注解

* @author hwt

@Retention(RetentionPolicy.RUNTIME)

@Target(ElementType.METHOD)

public @interface CheckTokenAnnocation {

}

二，新增自定义标签

1，在WEB-INF下新建一个tld标签文件，如下：

myTag.tld内容如下：

<?xml version="1.0" encoding="UTF-8" ?>

<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee web-jsptaglibrary_2_0.xsd"

version="2.0">

<description>自定义标签</description>

<tlib-version>1.0</tlib-version>

<jsp-version>1.2</jsp-version>

<short-name>myToken</short-name>

<tag>

<name>token</name>

<tag-class>com.hwt.common.TokenTag</tag-class>

<body-content>empty</body-content>

</tag>

</taglib>

2. 新建标签类，TokenTag.java (包路径与上面myTag.tld的tag-class中的内容一致)

/**

* 自定义标签：授权令牌

* @author hwt

public class TokenTag extends TagSupport{

private static final long serialVersionUID = -3347882989992304183L;

@Override

public int doStartTag() throws JspException {

//获取request对象

HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();

//令牌UUID

String tokenID = UUID.randomUUID().toString();

request.getSession().setAttribute("stoken", tokenID);

try {

pageContext.getOut().print("<input type='hidden' value='"+tokenID+"' name='rtoken'/>");

} catch (IOException e) {

e.printStackTrace();

}

return (SKIP_BODY);

}

3.在web.xml中配置自定义标签

<jsp-config>

<taglib-uri>/mytaglib</taglib-uri>

<taglib-location>/WEB-INF/myTag.tld</taglib-location>

</taglib>

</jsp-config>

三，新建拦截器类

/**

* 防止重复提交拦截器

* @author hwt

public class TokenInterceptor extends HandlerInterceptorAdapter{

/**

* 在进入提交方法的时候拦截

@Override

public boolean preHandle(HttpServletRequest request, HttpServletResponse response,

Object handler) throws Exception {

if (handler instanceof HandlerMethod) {

HandlerMethod handlerMethod = (HandlerMethod) handler;

CheckTokenAnnocation ct = handlerMethod.getMethodAnnotation(CheckTokenAnnocation.class);

if (ct != null) {

if(!checkToken(request)){

response.setContentType("text/html;charset=utf-8");

response.getWriter().print("<script>alert('重复提交！');</script>");

return false;

}

return true;

}

/**

* 判断是否是重复提交

* @param request

* @return

private boolean checkToken(HttpServletRequest request){

//request中的token

String rtoken = request.getParameter("rtoken");

//session中的token

HttpSession session = request.getSession();

String stoken = (String) session.getAttribute("stoken");

// token相等或服务器token已销毁时，不是重复提交

if (StringUtils.isBlank(stoken) || StringUtils.equals(rtoken, stoken)) {

session.setAttribute("stoken", UUID.randomUUID().toString());

return true;

}else {

return false;

}

四，使用：

1.在页面导入自定义标签

2.在表单中加入<my:token/>标签

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%@ taglib prefix="my" uri="/mytaglib"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>测试重复提交</title>

</head>

<body>

<my:token/>

</form>

</body>

</html>

3.在需要防止重复提交的方法上加入注解

@CheckTokenAnnocation

@RequestMapping("/test/test.action")

public String test(){

return "test/MyJsp";

}

0 0