In the past, we wrote to prevent repeated submissions, that is, adding a judgment in js to determine that the user cannot submit again. In fact, this can only prevent simple repeated submissions, next, I will introduce Struts2's method to prevent repeated submission of forms. The principle is probably that, like your verification code, each time you generate a sequence ID in the form of a hidden field, we can then verify it.
Configure the Interceptor to control repeated submissions! In fact, the principle is very simple. It is to generate a sequence in the form and determine whether it is a new sequence. If it is a previous sequence, it turns out to be a repeated submitted content!
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<? 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 = "common" extends = "struts-default" namespace = "/common">
<Interceptors>
<Interceptor-stack name = "loginStack">
<Interceptor-ref name = "defaultStack"> </interceptor-ref>
<Interceptor-ref name = "token"> </interceptor-ref>
</Interceptor-stack>
</Interceptors>
<Default-interceptor-ref name = "loginStack"> </default-interceptor-ref>
<Action name = "loginAction _ *" class = "loginAction" method = "{1}">
<Result name = "success">/welcome. jsp </result>
<Result name = "invalid. token" type = "redirect">/index. jsp </result>
<Result name = "input" type = "redirect">/index. jsp </result>
</Action>
</Package>
</Struts> |
Note:
If you do not reference:
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<Interceptor-ref name = "defaultStack"> </interceptor-ref> you cannot receive parameters in the background. <Result name = "invalid. token" type = "redirect">/index. jsp </result>
<Result name = "input" type = "redirect">/index. jsp </result> |
You must configure these two responses! One is the processing of repeated submissions, and the other is the processing without form tags!
Add Struts tag reference in JSP
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<% @ Taglib prefix = "s" uri = "/struts-tags" %> Add a tag to the form: <S: form action = "" name = "form1" method = "post">
<S: token> </s: token>
</S: form> |
Two hidden fields are displayed on the page:
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<Input type = "hidden" name = "struts. token. name" value = "struts. token"/>
<Input type = "hidden" name = "struts. token" value = "bxpnndg6bb11zxhpi4e1_cz5k7vnmhr"/> |
As mentioned above, there may be some friends who do not understand it. I will give you an example below.
Struts. xml configuration file
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<? 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>
<! -- Default view topic -->
<Constant name = "struts. ui. theme" value = "simple"/> <! -- Struts2 has two interceptions to prevent repeated form submission: token and tokenSession. The tokenSession inherits the token.
Generally, the tokenSession client is friendly. -->
<! -- If the request is submitted repeatedly, the error. jsp page is displayed. -->
<Package name = "person" namespace = "/test" extends = "struts-default">
<Action name = "token" class = "com. ljq. action. PersonAction">
<Interceptor-ref name = "defaultStack"/>
<Interceptor-ref name = "token"/>
<! -- If the request is submitted repeatedly, go to the error. jsp page -->
<Result name = "invalid. token">/WEB-INF/page/error. jsp </result>
<Result>/WEB-INF/page/message. jsp </result>
</Action>
<Action name = "tokenSession" class = "com. ljq. action. PersonAction">
<Interceptor-ref name = "defaultStack"/>
<Interceptor-ref name = "tokenSession"/>
<! -- If repeated submissions are made, the error. jsp page is not displayed. -->
<Result name = "invalid. token">/WEB-INF/page/error. jsp </result>
<Result>/WEB-INF/page/message. jsp </result>
</Action>
</Package>
</Struts> |
PersonAction class
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Package com. ljq. action;
Import java. util. ArrayList;
Import java. util. List;
Public class PersonAction {
Private String name; @ SuppressWarnings ("unchecked ")
// Watch the Console
// If the token takes effect, the name value will not be output on the console, but the following warning will be output: 20:45:32 com. opensymphony. xwork2.util. logging. commons. CommonsLogger
// Warn warning: Form token EDZ4S96RNDN5VD8B1CQTK6FTHIJUPC66 does not match the session token null.
Public String execute (){
List ls = new ArrayList ();
Ls. add (name );
For (int I = 0; I <ls. size (); I ++ ){
System. out. println (ls. get (I ));
}
Return "success ";
}
Public String getName (){
Return name;
} Public void setName (String name ){
This. name = name;
}
} |
Index. jsp form page
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<% @ Page language = "java" import = "java. util. *" pageEncoding = "UTF-8" %>
<% @ Taglib uri = "/struts-tags" prefix = "s" %>
<! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN">
<Html>
<Head>
<Title> prevent repeated submission of forms </title>
<Meta http-equiv = "pragma" content = "no-cache">
<Meta http-equiv = "cache-control" content = "no-cache">
<Meta http-equiv = "expires" content = "0">
</Head>
<Body>
<! -- Prevent repeated submission of forms. Remember to enter <s: token> </s: token> --> in the form.
<! -- Action = "token", action = "tokenSession" -->
<S: form action = "token" namespace = "/test" method = "post">
Name: <s: textfield name = "name"/> <s: token> </s: token>
<Input type = "submit" value = "send"/>
</S: form>
</Body>
</Html>
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Message. jsp return success page
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<% @ Page language = "java" import = "java. util. *" pageEncoding = "UTF-8" %>
<% @ Taglib uri = "/struts-tags" prefix = "s" %>
<! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN">
<Html>
<Head>
<Title> My JSP 'index. 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">
</Head>
<Body>
<S: property value = "name"/> <br/>
<% = New Date () %>
</Body>
</Html> |
