Welcome!

AJAX & REA Authors: Aria Blog, Rajesh Lain, Sebastian Kruk, RealWire News Distribution, Harald Zeitlhofer

Related Topics: AJAX & REA, Java

AJAX & REA: Article

Struts Validations Framework Using AJAX

Real-time data validation is one of the advantages of AJAX technology

Real-time data validation is one of the advantages of AJAX technology. By applying this technology, the struts validation framework will enrich the struts MVC and move the Web application closer to the desktop application.

The validation framework is used to validate fields. There are many ways to do validation on a Web application. It falls into two categories: server-side and client-side. A struts validation framework is one of the best frameworks for a Java-based Web application environment. It can configure the application using server-side validation and employ the error message that renders on the validation process invoked during the request processing time, or it can do client-side validation by using the JavaScript rendered on the requested page.

AJAX is a JavaScript technology that can asynchronously call the server and fetch the XML documents that are so popular lately. One of its uses is real-time data validation.

This article is concerned with enriching the existing struts validation framework with AJAX. A few components, such as a controller, have to be developed to select the validation framework and render the specific format message for the client side and a taglib to handle the error message rendering.

Prerequisites
You'll need a Windows system with Eclipse and the Tomcat application server. Make sure that the MSXML 3.0 ActiveX object is registered on your operating system. You'll also need the Struts library (http://struts.apache.org) and the JDOM library (www.jdom.org) for XML development (see Figure 1 and Figure 2).

Server-Side Scenario
StrustsActionServlet
We have to extend the class from org.apache.struts.action.ActionServlet to get the servletMapping variable that stores the information on how the extension will be formatted for action classes into the action path as a browser address. When the code is added, we have to configure web.xml as a Web application descriptor for the application server.

The web.xml configuration:

...
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>net.sf.struts.servlet.StrutsActionServlet</servlet-class>
...
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
...

The StrutsActionServlet Java code looks like this:

public class StrutsActionServlet extends the ActionServlet.
{
public String getServletMapping() {
return this.servletMapping;
}
}

AjaxValidationRequestProcessor
To support the existing Struts framework in the first step, we have to extend the RequestProcessor from the Struts package. We have to customize the request processor because we have to distinguish how we're going to do the validation - by using the existing Struts framework or the AJAX concept - and because we'll be making a contract between the server and client on how to interpret the message. In the message rendering we'll use the XML format, which is a good media messaging format. The definition of the XML format we'll apply is:

XML Format
<?xml version="1.0" encoding="UTF-8"?>
<message>
<identity name=messageAreaId>
     <description>
   MessageValue
</description>
</identity>
</message>

Description

  • Identity is the ID for the client JavaScript to acknowledge where the message will be placed.
  • Description is the result after the error message rendering from the server side.
First we need to get the servlet mapping configuration from the Web descriptor before moving onto the process mapping. After invoking the process, the application will prepare the instance of the form that inherits from the AjaxForm class. The processing manages AJAX validation and should check to ensure that the request from the client isn't using the struts validation framework. Other processes to perform during the request are process populate for collecting the information sent by the client into the action form, and process validation by using the method from the existing Struts validation framework that already exists in the parent class of AjaxValidationRequestProcessor (TilesRequestProcessor).

The validation process from the TilesRequestProcessor will invoke all the validation based on the struts validation framework and store the action errors into the request. What we need is to parse the action errors into pieces and generate the XML message validation that will be sent to the client side. Since we want to change the behavior of how the validation will be backed, the validation process should check the indicator of the validation framework being used (see Figure 3).

Generate the XML messages using JDOM as the processing engine. As shown in Figure 4, when the process validation is invoked and the condition of the validation framework is equal with the AJAX validation framework, the process will continue to populate the error message and build the XML message validation.

ErrorMessageHandler
This class handles the functionality of the XML message builder. This Java class will be building the XML message based on the identity and description property. After the caller invokes the buildXMLMessage, it will prepare the document and set the root element of the XML message. This class also has an addNextXMLMessage function to add more validation messages into the XML (see Listing 1).

The process method will set the content type of the response as "text/xml" and send the XML message as a string. The function of the process on the AjaxValidationRequestProcessor code will look like Listing 2.

The processValidation method will populate the action errors and construct the message based on the format contract of the XML for the client. The function of processValidation on AjaxValidationRequestProcessor code will be look like:

...
ActionErrors errors = (ActionErrors) request.getAttribute(Globals.ERROR_KEY);
Locale locale = (Locale) request.getAttribute(Globals.LOCALE_KEY);
generateXMLMessage(errors, identity, locale, sbXMLMessage);
...

Client-Side Scenario
Build the Taglib Component

  • AjaxJavaScriptLibraryTag: The taglib component to render the JavaScript function at the client side for basic XMLHTTP controller functions.
  • AjaxErrorHtmlRenderTag: The taglib component to render the area of the error message at the JSP page.
Configuring the Taglib Definition
After developing the taglib component, we need to configure the taglib tld file as shown in Listing 3.

Build JSP and Struts Configuration
To simulate the result of the validation processing, we first need to build the presentation layer by incorporating the taglib that we've build. In this case I'm trying to give an example validation by using the validation rules component from Struts, and also the validation that comes from the form itself. Prepare five textboxs under the JSP page. The first to fourth textbox are using the validation rule configuration, and the fifth textbox is using the validate process from the action form. Other than that, we also need a submit button to simulate that after submitting the form, the existing struts validation are still working without AJAX. The user interface will look like Figure 5.

More Stories By Sonny Hastomo

Sonny Hastomo is an IT architect at Sun Microsystems, Indonesia, for the telecommunication industry division. His currently is focusing on providing solution design, sizing, implementation, consulting services, and quality support to customers in their evaluation of their IT challenges.

Comments (9) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
hanan mahmoud 07/27/08 03:39:45 AM EDT

hi all
its realy great article and it helped me to understand validation in ajax better ,i just hope if any one have sample code about that topic because till now i don't know how to find one and also i don't know where to put the code samples in the article so plz help me

Commenter 05/17/06 01:40:52 PM EDT

I just need examples, and I can´t find it here. This article is weak.

SYS-CON Belgium News Desk 05/02/06 03:27:56 PM EDT

Struts Validations Framework Using AJAX
Real-time data validation is one of the advantages of AJAX technology. By applying this technology, the struts validation framework will enrich the struts MVC and move the Web application closer to the desktop application.

SYS-CON Australia News Desk 05/02/06 01:44:38 PM EDT

Real-time data validation is one of the advantages of AJAX technology. By applying this technology, the struts validation framework will enrich the struts MVC and move the Web application closer to the desktop application.

AJAX News Desk 05/02/06 12:55:46 PM EDT

AjaxWorld: Struts Validations Framework Using AJAX
Real-time data validation is one of the advantages of AJAX technology. By applying this technology, the struts validation framework will enrich the struts MVC and move the Web application closer to the desktop application.

Rajesh 05/02/06 12:17:24 PM EDT

The article was really nice.It would have been better if the source code was included.

Thanks

waikit 02/08/06 04:11:11 AM EST

can I have a sample code of the example shown in this article, please

regards

SYS-CON Australia News Desk 01/27/06 02:21:45 PM EST

Real-time data validation is one of the advantages of AJAX technology. By applying this technology, the struts validation framework will enrich the struts MVC and move the Web application closer to the desktop application.

Artem Vasiliev 01/26/06 06:18:56 AM EST

Sonnie, thank you for your article, it brings pretty interesting idea.
It would be great to see some sample application (with source code of course) implementing this approach. I even thought that I would find as a source code for the article, but seems like JDJ doesn't have such practice. Sonnie, can you provide that? It could be an archive hosted somewhere, here or at some free hosting, e.g. http://rapidshare.de/

@CloudExpo Stories
Performance is the intersection of power, agility, control, and choice. If you value performance, and more specifically consistent performance, you need to look beyond simple virtualized compute. Many factors need to be considered to create a truly performant environment. In their General Session at 15th Cloud Expo, Phil Jackson, Development Community Advocate at SoftLayer, and Harold Hannon, Sr. Software Architect at SoftLayer, to discuss how to take advantage of a multitude of compute options and platform features to make cloud the cornerstone of your online presence.
Come learn about what you need to consider when moving your data to the cloud. In her session at 15th Cloud Expo, Skyla Loomis, a Program Director of Cloudant Development at Cloudant, will discuss the security, performance, and operational implications of keeping your data on premise, moving it to the cloud, or taking a hybrid approach. She will use real customer examples to illustrate the tradeoffs, key decision points, and how to be successful with a cloud or hybrid cloud solution.
In today's application economy, enterprise organizations realize that it's their applications that are the heart and soul of their business. If their application users have a bad experience, their revenue and reputation are at stake. In his session at 15th Cloud Expo, Anand Akela, Senior Director of Product Marketing for Application Performance Management at CA Technologies, will discuss how a user-centric Application Performance Management solution can help inspire your users with every application transaction.
With the explosion of the cloud, more businesses are transitioning to a recurring revenue model to generate reliable sales, grow profits, and open new markets. This opportunity requires businesses to get to market quickly with the pricing and packaging options customers want. In addition, you will want to take advantage of the ensuing tidal wave of data to more effectively upsell, cross-sell and manage your customers. All of this is possible, but only with the right approach. At 15th Cloud Expo, Brendan O'Brien, Co-founder at Aria Systems and the inventor of cloud billing panelists, will lead a panel discussion on what it takes to launch and manage a successful recurring revenue business. The panelists will offer their insights about what each department will need to consider, from financial management to line of business and IT. The panelists will also offer examples from their success in recurring revenue with companies such as Audi, Constant Contact, Experian, Pitney-Bowes, Teleko...
Planning scalable environments isn't terribly difficult, but it does require a change of perspective. In his session at 15th Cloud Expo, Phil Jackson, Development Community Advocate for SoftLayer, will broaden your views to think on an Internet scale by dissecting a video publishing application built with The SoftLayer Platform, Message Queuing, Object Storage, and Drupal. By examining a scalable modular application build that can handle unpredictable traffic, attendees will able to grow your development arsenal and pick up a few strategies to apply to your own projects.
The cloud provides an easy onramp to building and deploying Big Data solutions. Transitioning from initial deployment to large-scale, highly performant operations may not be as easy. In his session at 15th Cloud Expo, Harold Hannon, Sr. Software Architect at SoftLayer, will discuss the benefits, weaknesses, and performance characteristics of public and bare metal cloud deployments that can help you make the right decisions.
Over the last few years the healthcare ecosystem has revolved around innovations in Electronic Health Record (HER) based systems. This evolution has helped us achieve much desired interoperability. Now the focus is shifting to other equally important aspects – scalability and performance. While applying cloud computing environments to the EHR systems, a special consideration needs to be given to the cloud enablement of Veterans Health Information Systems and Technology Architecture (VistA), i.e., the largest single medical system in the United States.
Cloud and Big Data present unique dilemmas: embracing the benefits of these new technologies while maintaining the security of your organization’s assets. When an outside party owns, controls and manages your infrastructure and computational resources, how can you be assured that sensitive data remains private and secure? How do you best protect data in mixed use cloud and big data infrastructure sets? Can you still satisfy the full range of reporting, compliance and regulatory requirements? In his session at 15th Cloud Expo, Derek Tumulak, Vice President of Product Management at Vormetric, will discuss how to address data security in cloud and Big Data environments so that your organization isn’t next week’s data breach headline.
Scott Jenson leads a project called The Physical Web within the Chrome team at Google. Project members are working to take the scalability and openness of the web and use it to talk to the exponentially exploding range of smart devices. Nearly every company today working on the IoT comes up with the same basic solution: use my server and you'll be fine. But if we really believe there will be trillions of these devices, that just can't scale. We need a system that is open a scalable and by using the URL as a basic building block, we open this up and get the same resilience that the web enjoys.
Is your organization struggling to deal with skyrocketing volumes of digital assets? The amount of data is growing exponentially and organizations are having a hard time managing this growth. In his session at 15th Cloud Expo, Amar Kapadia, Senior Director of Open Cloud Strategy at Seagate, will walk through the essential considerations when developing a cloud storage strategy. In this discussion, you will understand the challenges IT is facing, why companies need to move to cloud, and how the right cloud model can help your business economically overcome the data struggle.
If cloud computing benefits are so clear, why have so few enterprises migrated their mission-critical apps? The answer is often inertia and FUD. No one ever got fired for not moving to the cloud – not yet. In his session at 15th Cloud Expo, Michael Hoch, SVP, Cloud Advisory Service at Virtustream, will discuss the six key steps to justify and execute your MCA cloud migration.
The 16th International Cloud Expo announces that its Call for Papers is now open. 16th International Cloud Expo, to be held June 9–11, 2015, at the Javits Center in New York City brings together Cloud Computing, APM, APIs, Security, Big Data, Internet of Things, DevOps and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal today!
Most of today’s hardware manufacturers are building servers with at least one SATA Port, but not every systems engineer utilizes them. This is considered a loss in the game of maximizing potential storage space in a fixed unit. The SATADOM Series was created by Innodisk as a high-performance, small form factor boot drive with low power consumption to be plugged into the unused SATA port on your server board as an alternative to hard drive or USB boot-up. Built for 1U systems, this powerful device is smaller than a one dollar coin, and frees up otherwise dead space on your motherboard. To meet the requirements of tomorrow’s cloud hardware, Innodisk invested internal R&D resources to develop our SATA III series of products. The SATA III SATADOM boasts 500/180MBs R/W Speeds respectively, or double R/W Speed of SATA II products.
SYS-CON Events announced today that Gridstore™, the leader in software-defined storage (SDS) purpose-built for Windows Servers and Hyper-V, will exhibit at SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Gridstore™ is the leader in software-defined storage purpose built for virtualization that is designed to accelerate applications in virtualized environments. Using its patented Server-Side Virtual Controller™ Technology (SVCT) to eliminate the I/O blender effect and accelerate applications Gridstore delivers vmOptimized™ Storage that self-optimizes to each application or VM across both virtual and physical environments. Leveraging a grid architecture, Gridstore delivers the first end-to-end storage QoS to ensure the most important App or VM performance is never compromised. The storage grid, that uses Gridstore’s performance optimized nodes or capacity optimized nodes, starts with as few a...
SYS-CON Events announced today that Cloudian, Inc., the leading provider of hybrid cloud storage solutions, has been named “Bronze Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Cloudian is a Foster City, Calif.-based software company specializing in cloud storage. Cloudian HyperStore® is an S3-compatible cloud object storage platform that enables service providers and enterprises to build reliable, affordable and scalable hybrid cloud storage solutions. Cloudian actively partners with leading cloud computing environments including Amazon Web Services, Citrix Cloud Platform, Apache CloudStack, OpenStack and the vast ecosystem of S3 compatible tools and applications. Cloudian's customers include Vodafone, Nextel, NTT, Nifty, and LunaCloud. The company has additional offices in China and Japan.
SYS-CON Events announced today that TechXtend (formerly Programmer’s Paradise), a leading value-added provider of server and storage virtualization, and r-evolution will exhibit at SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. TechXtend (formerly Programmer’s Paradise) is a leading value-added provider of software, systems and solutions for corporations, government organizations, and academic institutions across the United States and Canada. TechXtend is the Exclusive Reseller in the United States for r-evolution
Every healthy ecosystem is diverse. This is especially true in cloud ecosystems, where portability and interoperability are more important than old enterprise models of proprietary ownership. In his session at 15th Cloud Expo, Mark Baker, Server Product Manager at Canonical/Ubuntu, will discuss how single vendors used to take the lead in creating and delivering technology, but in a cloud economy, where users want tools of their preference, when and where they need them, it makes no sense.
The emergence of cloud computing and Big Data warrants a greater role for the PMO to successfully manage enterprise transformation driven by these powerful trends. As the adoption of cloud-based services continues to grow, a governance model is needed to orchestrate enterprise cloud implementations and harness the power of Big Data analytics. In his session at 15th Cloud Expo, Mahesh Singh, President of BigData, Inc., to discuss how the Enterprise PMO takes center stage not only in developing the appropriate governance model but also in collaborating with key stakeholders to ensure a successful transformation.
The consumption economy is here and so are cloud applications and solutions that offer more than subscription and flat fee models and at the same time are available on a pure consumption model, which not only reduces IT spend but also lowers infrastructure costs, and offers ease of use and availability. In their session at 15th Cloud Expo, Ermanno Bonifazi, CEO & Founder of Solgenia, and Ian Khan, Global Strategic Positioning & Brand Manager at Solgenia, will discuss this shifting dynamic with an example of a top European Telco provider. Find out how they are leveraging the power of acloud-based consumption model services to offer more value to the mass market and enable a new revenue model that embraces the true meaning of the Third Industrial Revolution.
Cloud computing started a technology revolution; now DevOps is driving that revolution forward. By enabling new approaches to service delivery, cloud and DevOps together are delivering even greater speed, agility, and efficiency. No wonder leading innovators are adopting DevOps and cloud together! In his session at DevOps Summit, Andi Mann, Vice President of Strategic Solutions at CA Technologies, will explore the synergies in these two approaches, with practical tips, techniques, research data, war stories, case studies, and recommendations.