Why method prefix not working in Struts 2.3.32

Question

I use Struts 2.3.32 and this is the code.

methodPrefix.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <s:form action="methodPrefix" theme="simple">
        name: <br/>
        <s:textfield name="name"/>
        <br><br>
        <s:submit value="Create Person"/>
        <s:submit name="method:cancel" value="Cancel"/>
    </s:form>
</body>
</html>

MethodPrefixAction.java

   public class MethodPrefixAction 
    {
        private String name;
        private String message;
        
        public String execute() throws Exception
        {
            message = name + " create";
            return "success";
        }
        public String cancel() throws Exception
        {
            message = "cancel";
            return "success";
        }
        
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public String getMessage() {
            return message;
        }
        public void setMessage(String message) {
            this.message = message;
        }
    }

struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd">
<struts>
    <constant name="struts.mapper.action.prefix.enabled" value="true" />
     
    <package name="default" extends="struts-default" namespace="">
        <action name="goMethodPrefixPage">
            <result>/chapter4/methodPrefix.jsp</result>
        </action>
        <action name="methodPrefix" class="example.chapter4.MethodPrefixAction">
            <result>/chapter4/methodPrefixResult.jsp</result>
        </action>
    </package>
</struts>

when I push Cancel button, It do not call cancel() method, just call execute() method.

I don't know why method: prefix not work.

I searched a lot, and I know method: prefix configuration is false by default in Struts 2.3.32, so I used a constant..... but it did not work

It does not work. just error occured and cancellable both side. — Rikimaru, Jun 26 '17 at 07:04

Roman C · Accepted Answer · 2021-04-16T17:33:35.910

1

This constant

<constant name="struts.mapper.action.prefix.enabled" value="true" />

works only for action: prefix, not a method: prefix. So you should use the action attribute to submit tag.

<s:submit action="cancel" value="Cancel"/>

Note: If you have DMI turned off the action: prefix is still available.

edited Apr 16 '21 at 17:33

answered Jun 26 '17 at 09:02

Roman C

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then how can i use method prefix? – Rikimaru Jun 27 '17 at 02:05
1

for method prefix you should enable DMI, it's disabled by default for safety, if you want to enable it on your own risk see [this](https://stackoverflow.com/a/20772170/573032) answer – Roman C Jun 27 '17 at 09:01

Jay Smith · Answer 2 · 2017-06-26T07:12:59.827

This tutorial explains it and this tutorial shows how to do validation

Method MethodPrefixAction.execute should return success or cancel string.

In struts.xml you can redirect user to different pages based on return string:

<action name="methodPrefix" class="example.chapter4.MethodPrefixAction">
            <result name="success">/chapter4/methodPrefixResult.jsp</result>
            <result name="cancel">/chapter4/methodPrefix.jsp</result>
        </action>

Why method prefix not working in Struts 2.3.32

2 Answers2