Why aren't the Struts tags maintained as part of the Jakarta Taglibs project ?
Development of both products began about the same time. Leading up to the release of 1.0, it was thought better to continue to develop the taglibs alongside the controller. Now that 1.0 is out, the JavaServer Pages Standard Taglib is in active development. Once work on JSTL stabilizes, the Struts taglibs will be revisited. Tags which are not linked directly to the framework may be hosted at Jakarta Taglibs instead.

Are the Struts tags XHTML compliant ?
If you use an <html:html xhtml="true> or <html:xhtml/> element on your page, the tags will render as XHTML (since Struts 1.1).

Will the Struts tags support other markup languages such as WML  ?
Struts itself is markup neutral. The original Struts taglibs are only one example of how presentation layer components can access the framework. The framework objects are exposed through the standard application, session, and request contexts, where any Java component in the application can make use of them.
Markup extensions that use Struts are available for Velocity and XLST, among others. A new Struts tag library for Java Server Faces is also in development.
For more about using WAP/WML with Struts see the article WAP up your EAserver.

What about JSTL and JavaServer Faces ?
JSTL, the JavaServer Standard Tag Library, is a set of JSP tags that are designed to make it easier to develop Web applications. JavaServer Faces (JSF) is a specification for a new technology that promises to make it easier to write MVC applications, both for the Web and for the desktop.
The inventor of Struts, Craig McClanahan, is the specification co-lead for JavaServer Faces (JSR 127), and architect of the reference implemenation as well as Java Studio Creator. Both JSTL and JSF are complementary to Struts.
The mainstay of the Struts framework is the controller components, which can be used with any Java presentation technology. As new technologies become available, it is certain that new "glue" components will also appear to help these technologies work as well with Struts.
Struts originally came bundled with a set of custom JSP tags. Today, several extensions are available to help you use Struts with other popular presentation technologies, like XSLT and Velocity. Likewise, extensions for JSTL and JSF are now available as well.
The JSTL reference implementation is available through the Jakarta Taglibs site. A JSTL taglibs for Struts, Struts-El , is available and distributed with Struts beginning with the 1.1 release.
The JSF specification and reference implementation is available through Sun's The JSF specification and reference implementation is available through Sun's Java ServerFaces page. An early-release JavaServer Faces taglib for Struts, Struts-Faces, is also in early release and available through the nightly build. The Struts Faces taglib is expected to work with any compliant JSF implementation, including MyFaces.

Is there a particularly good IDE to use with Struts
Struts should work well with any development environment that you would like to use, as well as with any programmers editor. The members of the Struts development team each use their own tools such as Emacs, IDEA, Eclipse, and NetBeans.

Why was reload removed from Struts (since 1.1)?
The problem with ReloadAction was that Struts was trying to act like a container, but it couldn't do a proper job of it. For example, you can't reload classes that have been modified, or (portably) add new classes to a running web application (even if the container supported it).
Meanwhile, as Struts 1.1 was being developed, work progressed on things like Tomcat's reload command via the Manager webapp. This feature allows you to quickly reload-on-demand, complete with saving and restoring your session). It started to make even less sense for Struts to half-implement a feature that containers are implementing fully.
A more minor point is that freezing the configuration information at application startup time allows Struts to safely access the mapping information without bothering with synchronization. The "startup-only" strategy creates a modest but real improvement in performance for all users.
So, ReloadAction is not supported since Struts 1.1 for two reasons:
* It never did let you reload everything that you would really want to -- particularly changed classes -- so many people ended up having to reload the webapp anyway.
* Containers are starting to offer reload-on-demand features which does the same thing as the Struts ReloadAction, only better.
* Not supporting ReloadAction lets Struts avoid doing synchronization locks around all the lookups (like figuring out which action to use, or the destination of an ActionForward) so applications can run a little faster.
Of course, if someone came up with an implementation that solved these problems without creating any others, we would not be opposed to including a new ReloadAction.

What is a modular application? What does module-relative mean?
Since Struts 1.1, the framework supports multiple application modules. All applications have at least one root, or default, module. Like the root directory in a file system, the default application has no name. (Or is named with an empty string, depending your viewpoint.) Developing an application with only a default module is no different from how applications were developed under Struts 1.0. Since Struts 1.1, you can add additional modules to your application, each of which can have their own configuration files, messages resources, and so forth. Each module is developed in the same way as the default module. Applications that were developed as a single module can added to a multiple module application, and modules can promoted to a standalone application without change. For more about configuring your application to support multiple modules, see Configuring Applications in the User Guide.
But to answer the question =:0), a modular application is a Struts application that uses more than one module. Module-relative means that the URI starts at the module level, rather than at the context level, or the absolute-URL level.
* Absolute URL: http://localhost/myApplication/myModule/myAction.do
* context-relative: /myModule/myAction.do
* module-relative: /myAction.do
The Struts Examples application is a modular application that was assembled from several applications that were created independently.

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Why is it called Struts?
It's a reference to struts in the architectural sense, a reminder of the nearly invisible pieces that hold up buildings, houses, and bridges.

Do I have to credit Struts on my own website?
You need to credit Struts if you redistribute your own framework based on Struts for other people to use. (See the Apache License for details.) But you do not need to credit Struts just because your web application utilizes the framework. It's the same situation as using the Apache HTTPD server or Tomcat. Not required if its just running your web site.

Where can I get a copy of Struts?
The best place to download Struts is at struts.apache.org. The nightly builds are very stable, and recommended as the best place to start today.

How do I install Struts?
To develop applications with Struts, you can usually just add the Struts JAR file to your Java development environment. You can then start using the Struts classes as part of your own application. A blank Struts application (in the webapps directory, open struts-blank.war) is provided, which you can just copy to get a quick-start on your own brainchild.
Since the full source code for Struts is available, we also provide complete instructions for compiling your own Struts JAR from scratch. (This is actually easier than it looks!)
Your Struts application can usually be deployed using a standard WAR file. In most cases, you simply deposit the WAR file on your application server, and it is installed automatically. If not, step-by-step installation instructions for various servlet containers are available.

When do I need "struts.jar" on my classpath?
When you are compiling an application that uses the Struts classes, you must have the "struts.jar" on the classpath your compiler sees -- it does not have to be on your CLASSPATH environment variable.
Why is that an important distinction? Because if you are using a servlet container on your development machine to test your application, the "struts.jar" must not be on your CLASSPATH environment variable when running the container. (This is because each Web application must also have their own copy of the Struts classes, and the container will become confused if it is on the environment path as well.)
There are several general approaches to this issue:
* Use ANT for building your projects -- it can easily assemble classpaths for the compiler. (This is how Struts itself is built, along with Tomcat and most other Java-based projects).
* Use an IDE where you can configure the "class path" used for compilation independent of the CLASSPATH environment variable.
* Use a shell script that temporarily adds struts.jar to the classpath just for compilation, for example javac -classpath /path/to/struts.jar:$CLASSPATH $@

Does Struts include its own unit tests?
Struts currently has two testing environments, to reflect the fact that some things can be tested statically, and some really need to be done in the environment of a running servlet container.
For static unit tests, we use the JUnit framework. The sources for these tests are in the "src/test" hierarchy in the source repository, and are executed via the "test.junit" target in the top-level build.xml file. Such tests are focused on the low-level functionality of individual methods, are particularly suitable for the static methods in the org.apache.struts.util utility classes. In the test hierarchy, there are also some "mock object" classes (in the org.apache.struts.mock package) so that you can package up things that look like servlet API and Struts API objects to pass in as arguments to such tests.
Another valuable tool is Struts TestCase which provides a useful harness for Action classes that can be used with JUnit or Cactus.

If the framework doesn't do what I want, can I request that a feature be added?
First, it's important to remember that Struts is an all-volunteer project. We don't charge anyone anything to use Struts. Committers and other developers work on Struts because they need to use it with their own applications. If others can use it too, that's "icing on the cake". If you submit a patch for a feature that a Committer finds useful, then that Committer may choose to volunteer his or her time to apply the patch. If you just submit an idea without a patch, it is much less likely to be added (since first someone else has to volunteer their time to write the patch).
We are grateful for any patches, and we welcome new ideas, but the best way to see that something gets added to the framework is to do as much of the work as you can, rather than rely on the "kindness of strangers". Worst case, you can apply the patch to your copy of Struts and still use the feature in your own application. (Which is what open source is ~really~ all about.)

What's the difference between Struts and Turbine? What's the difference between Struts and Espresso?
If you are starting from scratch, packages like Turbine and Espresso can be very helpful since they try to provide all of the basic services that your team is likely to need. Such services include things like data persistence and logging.
If you are not starting from scratch, and need to hook up your web application to an existing infrastructure, then "plain vanilla" Struts can be a better choice. The core Struts framework does not presuppose that you are using a given set of data persistence, presentation, or logging tools. Anything goes =:0)
Compared to other offerings, Struts endeavors to be a minimalist framework. We try leverage existing technologies whenever we can and provide only the missing pieces you need to combine disparate technologies into a coherent application. This is great when you want to select your own tools to use with Struts. But, if you prefer a more integrated infrastructure, then packages like Turbine or Espresso (which uses Struts) are perfectly good ways to go.
See also
* < http://www.mail-archive.com/struts-user@jakarta.apache.org/msg03206.html >
* < http://www.mail-archive.com/general@jakarta.apache.org/msg00495.html >
* < http://jakarta.apache.org/velocity/ymtd/ymtd.html >

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What is Action Class?
The Action Class is part of the Model and is a wrapper around the business logic. The purpose of Action Class is to translate the HttpServletRequest to the business logic. To use the Action, we need to Subclass and overwrite the execute() method. In the Action Class all the database/business processing are done. It is advisable to perform all the database related stuffs in the Action Class. The ActionServlet (commad) passes the parameterized class to Action Form using the execute() method. The return type of the execute method is ActionForward which is used by the Struts Framework to forward the request to the file as per the value of the returned ActionForward object.

Write code of any Action Class?
Here is the code of Action Class that returns the ActionForward object.
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

public class TestAction extends Action
{
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception
{
return mapping.findForward(\"testAction\");
}
}

What is ActionForm?
An ActionForm is a JavaBean that extends org.apache.struts.action.ActionForm. ActionForm maintains the session state for web application and the ActionForm object is automatically populated on the server side with data entered from a form on the client side.

What is Struts Validator Framework?
Struts Framework provides the functionality to validate the form data. It can be use to validate the data on the users browser as well as on the server side. Struts Framework emits the java scripts and it can be used validate the form data on the client browser. Server side validation of form can be accomplished by sub classing your From Bean with DynaValidatorForm class. The Validator framework was developed by David Winterfeldt as third-party add-on to Struts. Now the Validator framework is a part of Jakarta Commons project and it can be used with or without Struts. The Validator framework comes integrated with the Struts Framework and can be used without doing any extra settings.

Give the Details of XML files used in Validator Framework?
The Validator Framework uses two XML configuration files validator-rules.xml and validation.xml. The validator-rules.xml defines the standard validation routines, these are reusable and used in validation.xml. to define the form specific validations. The validation.xml defines the validations applied to a form bean. How you will display validation fail errors on jsp page? - The following tag displays all the errors: < html:errors/ >

Why do we need Struts?
Java technologies give developers a serious boost when creating and maintaining applications to meet the demands of today's public Web sites and enterprise intranets. Struts combines Java Servlets, Java ServerPages, custom tags, and message resources into a unified framework. The end result is a cooperative, synergistic platform, suitable for development teams, independent developers, and everyone in between.

How does Struts work?
Java Servlets are designed to handle requests made by Web browsers. Java ServerPages are designed to create dynamic Web pages that can turn billboard sites into live applications. Struts uses a special Servlet as a switchboard to route requests from Web browsers to the appropriate ServerPage. This makes Web applications much easier to design, create, and maintain.

Is Struts compatible with other Java technologies?
Yes. Struts is committed to supporting industry standards. Struts acts as an integrator of Java technologies so that they can be used in the "real world".

Who wrote Struts?
There are several active committers to the Struts project, working cooperatively from around the globe. Dozens of individual developers and committers contributed to the Struts 1.x codebase. All interested Java developers are invited to contribute to the project. Struts is a Apache Software Foundation project, with the mission to "provide secure, enterprise-grade server solutions based on the Java Platform that are developed in an open and cooperative fashion".
Struts was created by Craig R. McClanahan and donated to The Apache Software Foundation in May 2000. Craig was the primary developer of both Struts 1.x and Tomcat 4. Tomcat 4 was the basis for the official reference implementation for a servlet 2.3 and JSP 1.2 container.
Craig's current focus is as architect of the Sun Java Studio Creator (formerly Project Rave). Craig also serves as the Specification Lead for JavaServer Faces (JSR-127), and is the Web Layer Architect for the Java2 Enterprise Edition (J2EE) platform as a whole.

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What is Struts?
Struts is a web page development framework and an open source software that helps developers build web applications quickly and easily. Struts combines Java Servlets, Java Server Pages, custom tags, and message resources into a unified framework. It is a cooperative, synergistic platform, suitable for development teams, independent developers, and everyone between.

How is the MVC design pattern used in Struts framework?
In the MVC design pattern, application flow is mediated by a central Controller. The Controller delegates requests to an appropriate handler. The handlers are tied to a Model, and each handler acts as an adapter between the request and the Model. The Model represents, or encapsulates, an application's business logic or state. Control is usually then forwarded back through the Controller to the appropriate View. The forwarding can be determined by consulting a set of mappings, usually loaded from a database or configuration file. This provides a loose coupling between the View and Model, which can make an application significantly easier to create and maintain.
Controller--Servlet controller which supplied by Struts itself; View --- what you can see on the screen, a JSP page and presentation components; Model --- System state and a business logic JavaBeans.

Who makes the Struts?
Struts is hosted by the Apache Software Foundation(ASF) as part of its Jakarta project, like Tomcat, Ant and Velocity.

Why it called Struts?
Because the designers want to remind us of the invisible underpinnings that hold up our houses, buildings, bridges, and ourselves when we are on stilts. This excellent description of Struts reflect the role the Struts plays in developing web applications.

Do we need to pay the Struts if being used in commercial purpose?
No. Struts is available for commercial use at no charge under the Apache Software License. You can also integrate the Struts components into your own framework just as if they were written in house without any red tape, fees, or other hassles.

What are the core classes of Struts?
Action, ActionForm, ActionServlet, ActionMapping, ActionForward are basic classes of Structs.

What is the design role played by Struts?
The role played by Structs is controller in Model/View/Controller(MVC) style. The View is played by JSP and Model is played by JDBC or generic data source classes. The Struts controller is a set of programmable components that allow developers to define exactly how the application interacts with the user.

How Struts control data flow?
Struts implements the MVC/Layers pattern through the use of ActionForwards and ActionMappings to keep control-flow decisions out of presentation layer.

What configuration files are used in Struts?

ApplicationResources.properties
struts-config.xml
These two files are used to bridge the gap between the Controller and the Model.

What helpers in the form of JSP pages are provided in Struts framework?
--struts-html.tld
--struts-bean.tld
--struts-logic.tld

Is Struts efficient?
The Struts is not only thread-safe but thread-dependent(instantiates each Action once and allows other requests to be threaded through the original object.
ActionForm beans minimize subclass code and shorten subclass hierarchies
The Struts tag libraries provide general-purpose functionality
The Struts components are reusable by the application
The Struts localization strategies reduce the need for redundant JSPs
The Struts is designed with an open architecture--subclass available
The Struts is lightweight (5 core packages, 5 tag libraries)
The Struts is open source and well documented (code to be examined easily)
The Struts is model neutral

How you will enable front-end validation based on the xml in validation.xml?
The < html:javascript > tag to allow front-end validation based on the xml in validation.xml. For example the code: < html:javascript formName=logonForm dynamicJavascript=true staticJavascript=true / > generates the client side java script for the form logonForm as defined in the validation.xml file. The < html:javascript > when added in the jsp file generates the client site validation script.

What is ActionServlet?
The class org.apache.struts.action.ActionServlet is the called the ActionServlet. In the the Jakarta Struts Framework this class plays the role of controller. All the requests to the server goes through the controller. Controller is responsible for handling all the requests.


How you will make available any Message Resources Definitions file to the Struts Framework Environment?
Message Resources Definitions file are simple .properties files and these files contains the messages that can be used in the struts project. Message Resources Definitions files can be added to the struts-config.xml file through < message-resources / > tag. Example: < message-resources parameter= MessageResources / >

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