Struts2防止表单重复提交

比眉伴天荒 2022-01-15 13:23 361阅读 0赞

[为什么80%的码农都做不了架构师？>>> ][80_]  ![hot3.png][]

防止表单重复提交主要用的到标签是<s: token />，拦截器 <interceptor-ref name="token" />，还有一个默认的返回值<result name="invalid.token">/input.jsp</result>     
  
  
  
  
在页面加载时，<s: token />产生一个GUID（Globally Unique Identifier，全局唯一标识符）值的隐藏输入框如：

1.  <input type="hidden" name="struts.token.name" value="struts.token"/>   
2.  <input type="hidden" name="struts.token" value="BXPNNDG6BB11ZXHPI4E106CZ5K7VNMHR"/>

同时，将GUID放到会话（session）中；在执行action之前，“token”拦截器将会话token与请求token比较，如果两者相同，则将会话中的token删除并往下执行，否则向actionErrors加入错误信息。如此一来，如果用户通过某种手段提交了两次相同的请求，两个token就会不同。  
  
以下为action代码

import com.opensymphony.xwork2.ActionSupport;          
          
public class TestAction extends ActionSupport \{                  
         private static final long serialVersionUID = 6820659617470261780L;          
                  
         private String message;          
                          
         public String getMessage() \{          
                 return message;          
        \}          
          
         public void setMessage(String message) \{          
                 this.message = message;          
        \}          
                  
        @Override          
         public String execute() \{          
                System.out.println( "Executing action, your message is " + message);          
                 return SUCCESS;          
        \}                  
\}

再看看JSP的写法

< %@ page language ="java" contentType ="text/html; charset=utf-8" pageEncoding ="utf-8" % >          
< %@ taglib prefix ="s" uri ="/struts-tags" % >          
          
< !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >          
< html xmlns ="http://www.w3.org/1999/xhtml" >          
< head >          
         < title >struts2 test token </title>          
         < s:head />          
</head>          
< body >                  
         < s:actionerror />          
         < s:form action ="testAction" >          
                 < s:textfield name ="message" label ="Message" />          
                 < s:token />     < %-- 注意这里--% >          
                 < s:submit />          
         </s:form>          
</body>          
</html>

下面是struts2的配置文件

<? xml version ="1.0" encoding ="UTF-8" ?>          
          
<!DOCTYPE struts PUBLIC          
        "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"          
        "http://struts.apache.org/dtds/struts-2.0.dtd">          
          
< struts >          
         < package name ="test" extends ="struts-default" namespace ="/testToken" >          
                 < action name ="test" class ="com.fhx.TestAction" >          
                         < result name ="invalid.token" >/input.jsp </ result >                                                          
                         < result >/input.jsp </ result >          
          
                     < interceptor-ref name ="defaultStack" />          
                     < interceptor-ref name ="token" />          
          
                 </ action >          
         </ package >          
</ struts >

以上XML片段值注意的是加入了“token”拦截器和“invalid.token”结果，因为“token”拦截器在会话token与请求token不一致时，将会直接返回“invalid.token”结果。

转载于:https://my.oschina.net/lichen/blog/264905

[80_]: https://my.oschina.net/u/2663968/blog/3051541
[hot3.png]: /images/20220115/6155f086fb754fb9a5c3a22dd3bd9e05.png