Welcome!

IoT User Interface Authors: Pat Romanski, Liz McMillan, Elizabeth White, AppDynamics Blog, Yakov Fain

Related Topics: IoT User Interface, Java IoT

IoT User Interface: 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
The pace of innovation, vendor lock-in, production sustainability, cost-effectiveness, and managing risk… In his session at 18th Cloud Expo, Dan Choquette, Founder of RackN, discussed how CIOs are challenged finding the balance of finding the right tools, technology and operational model that serves the business the best. He also discussed how clouds, open source software and infrastructure solutions have benefits but also drawbacks and how workload and operational portability between vendors ...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life sett...
Your business relies on your applications and your employees to stay in business. Whether you develop apps or manage business critical apps that help fuel your business, what happens when users experience sluggish performance? You and all technical teams across the organization – application, network, operations, among others, as well as, those outside the organization, like ISPs and third-party providers – are called in to solve the problem.
Machine Learning helps make complex systems more efficient. By applying advanced Machine Learning techniques such as Cognitive Fingerprinting, wind project operators can utilize these tools to learn from collected data, detect regular patterns, and optimize their own operations. In his session at 18th Cloud Expo, Stuart Gillen, Director of Business Development at SparkCognition, discussed how research has demonstrated the value of Machine Learning in delivering next generation analytics to imp...
It's easy to assume that your app will run on a fast and reliable network. The reality for your app's users, though, is often a slow, unreliable network with spotty coverage. What happens when the network doesn't work, or when the device is in airplane mode? You get unhappy, frustrated users. An offline-first app is an app that works, without error, when there is no network connection. In his session at 18th Cloud Expo, Bradley Holt, a Developer Advocate with IBM Cloud Data Services, discussed...
There are several IoTs: the Industrial Internet, Consumer Wearables, Wearables and Healthcare, Supply Chains, and the movement toward Smart Grids, Cities, Regions, and Nations. There are competing communications standards every step of the way, a bewildering array of sensors and devices, and an entire world of competing data analytics platforms. To some this appears to be chaos. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, Bradley Holt, Developer Advocate a...
Digital Initiatives create new ways of conducting business, which drive the need for increasingly advanced security and regulatory compliance challenges with exponentially more damaging consequences. In the BMC and Forbes Insights Survey in 2016, 97% of executives said they expect a rise in data breach attempts in the next 12 months. Sixty percent said operations and security teams have only a general understanding of each other’s requirements, resulting in a “SecOps gap” leaving organizations u...
SaaS companies can greatly expand revenue potential by pushing beyond their own borders. The challenge is how to do this without degrading service quality. In his session at 18th Cloud Expo, Adam Rogers, Managing Director at Anexia, discussed how IaaS providers with a global presence and both virtual and dedicated infrastructure can help companies expand their service footprint with low “go-to-market” costs.
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
"A lot of times people will come to us and have a very diverse set of requirements or very customized need and we'll help them to implement it in a fashion that you can't just buy off of the shelf," explained Nick Rose, CTO of Enzu, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, wh...
19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterpri...
What does it look like when you have access to cloud infrastructure and platform under the same roof? Let’s talk about the different layers of Technology as a Service: who cares, what runs where, and how does it all fit together. In his session at 18th Cloud Expo, Phil Jackson, Lead Technology Evangelist at SoftLayer, an IBM company, spoke about the picture being painted by IBM Cloud and how the tools being crafted can help fill the gaps in your IT infrastructure.
SYS-CON Events announced today that Bsquare has been named “Silver Sponsor” of SYS-CON's @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. For more than two decades, Bsquare has helped its customers extract business value from a broad array of physical assets by making them intelligent, connecting them, and using the data they generate to optimize business processes.
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
"SpeedyCloud's specialty lies in providing cloud services - we provide IaaS for Internet and enterprises companies," explained Hao Yu, CEO and co-founder of SpeedyCloud, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
There is little doubt that Big Data solutions will have an increasing role in the Enterprise IT mainstream over time. Big Data at Cloud Expo - to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA - has announced its Call for Papers is open. Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is...
The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Microservices 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 opportuni...
Creating replica copies to tolerate a certain number of failures is easy, but very expensive at cloud-scale. Conventional RAID has lower overhead, but it is limited in the number of failures it can tolerate. And the management is like herding cats (overseeing capacity, rebuilds, migrations, and degraded performance). Download Slide Deck: ▸ Here In his general session at 18th Cloud Expo, Scott Cleland, Senior Director of Product Marketing for the HGST Cloud Infrastructure Business Unit, discusse...