Apache Struts 2 Documentation > Home > Guides > Plugin Developers Guide > Struts 1 Plugin
Added by Ted Husted, last edited by James Holmes on Sep 05, 2007  (view change)

The Struts 1 plugin allows you to use existing Struts 1 Actions and ActionForms in Struts 2 applications.

This plugin provides a generic Struts 2 Action class to wrap an existing Struts 1 Action, org.apache.struts2.s1.Struts1Action. The wrapper class provides the expected calls to the legacy Struts 1 Action and ActionForm, converting incoming and outgoing objects into the expected forms. It works by using the scoped model driven technique that uses a single Object as the model for every page, very similar to how the Struts 1 ActionForm works. The plugin also provides several interceptors to emulate Struts 1 logic:

  • org.apache.struts2.s1.ActionFormValidatorInterceptor - Integrates the validation of ActionForms into the workflow of Struts 2
  • org.apache.struts2.s1.ActionFormResetInterceptor - Calls the reset() method on any discovered ActionForms
Warning

The Struts 1 plugin is currently only intended to allow you to run Strust 1 actions inside a Struts 2 application. It DOES NOT allow you to continue to use the Struts 1 tag libraries in your JSPs. Your JSPs must be converted to use the Struts 2 tag library.

There is a JIRA ticket open for enhancing this plugin to allow a more seamless transition from Struts 1 to Struts 2 by supporting continued use of the Struts 1 tag libraries in JSPs, however, there is not a scheduled time frame for that functionality to be made available. (Patches are welcomed!)

Features

  • Can use Struts 1 Actions and ActionForms with no code changes
  • Supports Commons Validator-enabled ActionForms

Usage

To use existing Struts 1 Actions and ActionForms in a Struts 2 application, create a normal Struts 2 configuration package in struts.xml, but have it extend struts1-default. The struts1-default package contains several interceptors and a default interceptor stack that work the plugin into the Struts 2 request process.

In the most simple case, where you have a Struts 1 Action that you want to use in Struts 2, configure a Struts 2 action using the wrapper:

Simple Struts 1 configuration
<action name="myAction" class="org.apache.struts2.s1.Struts1Action">
  <param name="className">com.mycompany.myapp.MyAction</param>
  <result>myAction.jsp</result>
</action>

Most likely, you will have an ActionForm that your Struts 1 Action expects. To use an ActionForm, the setup is a little more complicated because you'll need an interceptor that manages the creation and scope (to support request and session scoping like Struts 1) of the ActionForm.

Struts 1 Action with a session-scoped ActionForm

<action name="myFormAction" class="org.apache.struts2.s1.Struts1Action">
  <param name="className">com.mycompany.myapp.MyAction</param>

  <interceptor-ref name="scopedModelDriven">
    <param name="className">com.mycompany.myapp.MyForm</param>
    <param name="name">gangsterForm</param>
    <param name="scope">session</param>
  </interceptor-ref>
  <interceptor-ref name="struts1-default"/>

  <result>myAction.jsp</result>
</action>

Example

This example shows a few Struts 1 Actions, a session-scoped ActionForm, and validation that uses Commons Validator:

<?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="integration" extends="struts1-default" namespace="/integration">

    <interceptors>
      <interceptor name="gangsterForm" class="com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor">
        <param name="className">org.apache.struts2.showcase.integration.GangsterForm</param>
        <param name="name">gangsterForm</param>
      </interceptor>
      <interceptor name="gangsterValidation" class="org.apache.struts2.s1.ActionFormValidationInterceptor">
        <param name="pathnames">/org/apache/struts/validator/validator-rules.xml,/WEB-INF/validation.xml</param>
      </interceptor>

      <interceptor-stack name="integration">
        <interceptor-ref name="staticParams"/>
        <interceptor-ref name="gangsterForm"/>
        <interceptor-ref name="modelDriven"/>
        <interceptor-ref name="actionForm-reset"/>
        <interceptor-ref name="basicStack"/>
        <interceptor-ref name="gangsterValidation"/>
        <interceptor-ref name="workflow"/>
      </interceptor-stack>
    </interceptors>

    <default-interceptor-ref name="integration"/>
    <default-action-ref name="editGangster"/>

    <!-- Display entry page that uses Model-Driven technique -->
    <action name="editGangster" class="org.apache.struts2.s1.Struts1Action">
      <param name="className">org.apache.struts2.showcase.integration.EditGangsterAction</param>
      <result>modelDriven.jsp</result>
    </action>

    <!-- Display the result page whose content is populated using the Model-Driven technique -->
    <action name="saveGangster" class="org.apache.struts2.s1.Struts1Action">
      <param name="className">org.apache.struts2.showcase.integration.SaveGangsterAction</param>
      <param name="validate">true</param>
      <result name="input">modelDriven.jsp</result>
      <result>modelDrivenResult.jsp</result>
    </action>

  </package>
</struts>

Settings

This plugin doesn't support any global settings.

Installation

This plugin can be installed by copying the plugin jar into your application's /WEB-INF/lib directory. It will need the Struts 1 jar in order to function correctly.