Click here to close now.

Welcome!

Java Authors: Harry Trott, Liz McMillan, Pat Romanski, Andreas Grabner, Kevin Jackson

Related Topics: Eclipse

Eclipse: Article

Creating Web Applications with the Eclipse Web Tools Project

Using open source to develop Web applications, EJBs, and Web services

The Web Tools Project (WTP) by the Eclipse Foundation is a set of open source tools that substantially reduce the time required for the development of Web applications, EJBs, and Web services. The WTP's current version is 0.7.1 and version 1.0 is coming later this year. The framework provides wizards and tools to create EJBs, Web components such as servlets and JSPs, and Web services using the Axis engine. It also provides source editors for HTML, JavaScript, CSS, JSP, SQL, XML, DTD, XSD, and WSDL; graphical editors for XSD, WSDL, J2EE project builders, models, and a J2EE navigator; a Web service wizard, explorer, and WS-I Test Tools; and database access, query tools, and models.

In this article I'll show you how to develop and deploy a JSP Web application with WTP in less than an hour. I'll also cover the creation and deployment of a basic servlet and editing JSP with WTP. Let's develop the WTP application together but, first, we need to install the following software:

  1. J2SE 5.0 JRE: http://java.sun.com/j2se
  2. Eclipse 3.1: www.eclipse.org
  3. WTP 0.7.1: www.eclipse.org/webtools
  4. Tomcat 5.0: http://jakarta.apache.org/tomcat/
  5. MySQL 4.0.25: www.mysql.com
  6. MySQL Connector/J Driver 3.1: www.mysql.com/products/connector/j/

Application Overview
Our application will be a basic Web application implementing the following use cases:

  • Customers need to register on the site to place orders.
  • Customers can place orders.
  • Customers can view their orders.
  • Admin can list all registered customers.

The system will be implemented using a servlet programming model and MySQL database.

Configuring MySQL Database and the Data Source
By default, when MySQL gets installed, a TEST database is available. Be sure to launch C:\Mysql\winmysqladmin.exe to specify the user name and password (the first time you launch it, it lets you do it and also starts the database server). It's necessary to copy MySQL Connector/J JDBC Driver: mysql-connector-java-3.1.10-bin.jar to the Tomcat/common/lib directory, so the Tomcat server can recognize it.

To configure MySQL database access in Tomcat, we have to add a separate file called Listing 1: DBTest.xml; the file follows a convention of "application_name.xml" under $TOMCAT\conf\catalina\localhost directory. The only problem with this file is that it may get deleted when the application is undeployed, so if you undeploy and redeploy the application, you have to place this file into the same folder again (so it's a good idea to save it somewhere else). Looking inside the DBTest.xml file, please note that in our case we are using "ODBC" for the username and don't provide any password.

Building Our Web Application Using Web Tools and a Database
Before we can start working on the Web project, we must configure Tomcat 5.0 in Eclipse to be our default server. When Web Tools are installed in Eclipse, new perspectives and options are added, such as a J2EE perspective where you can create J2EE projects, Web projects, and Web services. New options are available under the Window-Preferences menu for configuring Tomcat servers with Eclipse. Go to Window - Preferences menu, under Server select - Installed Runtimes, click Add, and then specify Tomcat 5.0 server with the installed JRE and a path to the Tomcat installation directory (see Figure 1). Now create a Dynamic Web Project using the Web Tools wizard by selecting File-New-Other, then expanding Web-Dynamic Web Project.

We'll name the project DBTest, which will also become its context root. The Web module will be targeted to our default server: Tomcat. Click Finish and the DBTest Web project gets created. This project will contain all of our Web resources, such as HTML and JSP files, and servlets, and you'll be able to export it into a standard WAR file later, if needed.

Creating Supporting Domain Classes and Tables
Before creating servlets, let's create supporting classes to represent a customer and an order. The class diagram in Figure 2 depicts the Customer and Order relationship.

Note that when creating Customer and Order classes, we define corresponding fields as their public instance variables and then can automatically generate getters and setters from those fields. This can be easily done by going to Outline view (appears after you double-click on an existing class name or create a new class), selecting a class, and selecting "Source - Generate Getters and Setters..." from the right-button menu (see Figure 3).

Along with the classes, we'd have to create corresponding database tables in a MySQL database:


CREATE TABLE CUSTOMER (
ID INT PRIMARY KEY,
FIRST_NAME VARCHAR(50),
LAST_NAME VARCHAR(50),
ADDRESS VARCHAR(150));

CREATE TABLE ORDERS (
ID INT PRIMARY KEY,
CUST_ID INT REFERENCES CUSTOMER,
DATE_PLACED DATE,
AMOUNT INT);

Creating Database Command Classes
We'll create a special package with classes that implement a Command design pattern to perform necessary database updates. The Command pattern allows the classes to implement the common interface executing some particular command. Examples of the Command pattern in Java would be classes that implement the ActionListener interface with the actionPerformed() method. Our Command pattern interface for database integration is presented in Listing 2.

Classes implementing this command will be performing the actual database operations for reading and inserting rows into customer and order tables. The following use cases will be addressed:

  • Customers want to register on the site in order to place orders (a new row is created in the customer table)
  • Customers can place the order (the order gets created in the database for a particular customer)
  • Customers can view the orders they have placed
  • Admin can list all the customers

Based on these use cases, the following classes have implemented the DatabaseCommand interface (see Listings 3-6):

public class CreateCustomer implements DatabaseCommand
public class CreateOrder implements DatabaseCommand
public class ListCustomers implements DatabaseCommand
public class ListCustomerOrders implements DatabaseCommand

Finally, in order to execute our command classes, we will need to create a class that would access the database datasource, obtain a SQL connection, and then execute a particular database command. This class will implement a Singleton design pattern, which we'll call CommandExecutor:

Object o = CommandExecutor.getInstance().executeDatabaseCommand
(<<instance of the particular database command class goes here>>).

The CommandExecutor class will perform the datasource lookup as follows:

InitialContext ctx = new InitialContext();
Context envCtx = (Context) ctx.lookup("java:comp/env");
ds = (DataSource) envCtx.lookup("jdbc/TestDB");

This finds the reference to the data-source we have defined in DBTest.xml by resolving its reference in a Web deployment descriptor (web.xml), which we'll define in a section below. Listing 7 has the complete code of the Command Executor class.

More Stories By Boris Minkin

Boris Minkin is a Senior Technical Architect of a major financial corporation. He has more than 15 years of experience working in various areas of information technology and financial services. Boris is currently pursuing his Masters degree at Stevens Institute of Technology, New Jersey. His professional interests are in the Internet technology, service-oriented architecture, enterprise application architecture, multi-platform distributed applications, and relational database design. You can contact Boris at [email protected]

Comments (15) 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
Mintara 12/26/07 04:11:21 PM EST

Hello Sir,
Could you please elaborate (for e.g the classes ..I could not find the source code)what you have explained.
Thank you.

Serge Cambour 09/25/07 06:38:15 AM EDT

It would be really a very good article or a tutorial if the author had tested it himself before posting it. I don't even talk of missing details, classes, code mistakes, ets. that make you loose any wish to continue.

Keith Freeman 07/15/06 10:32:01 PM EDT

Well, this seems like a fantastic tutorial, until suddenly the "CreateCustomerServlet" description morphs into a "ListCustomersServlet". We're left to figure out how to finish the servlets ourselves (still in progress for me), since as others point out here a bunch of code is missing from the zip file download. VERY disappointing after such a strong start.

David Paules 05/24/06 04:04:22 PM EDT

Good introduction article. Unfortunately, it's not clear where the database connection file DBTest.xml should reside when running Tomcat under Eclipse. Where does this file or it's content go in the Dynamic Web project tree? Because of this, I get an error message at debug time:

javax.servlet.ServletException: Cannot create JDBC driver of class '' for connect URL 'null'

Chuck Ferrick 05/20/06 09:24:58 PM EDT

I was very interesting article, but most of the listings where not posted. I was hoping to gain some insight on how you configure Hibernate. Your article stated to look at listing 9, but listing 9 was know where to be found. I was also frustrated when I could not find the DBTest.war file on java.sys-con web site.

Good furture article and maybe next time JDJ will include all of the necesasry file listings.

Achille Komla 02/05/06 10:57:41 PM EST

Very well done. It will be good to see how the application works with hibernate.

Daniel Hillebrand 12/15/05 04:35:56 AM EST

Hi Boris,

thank you for your great tutorial! Maybe you could add a note to your article regarding running Tomcat in eclipse:

You have to put the content of DBTest.xml in the (new) file context.xml in "WebContent/META-INF". The path strings are not needed, except the "path" string.

regards, Daniel

Bill Gercken 12/09/05 09:02:38 AM EST

Soource code: For those who did not find it: the link to the source is at the top of listing 1. View link: http://res.sys-con.com/story/nov05/152270/source.html

km 12/07/05 03:41:46 PM EST

could you provide the link for the source code

Paul Mischler 12/05/05 04:39:16 PM EST

Did anyone notice that listings 3-10 aren't included in the dead-tree edition?

Corrections to the article:

For the code to work "out of the box", the Customer and Order classes need to be created in a package called "domain"

Figure 2 shows "cust_id" as a member of the Order class. However, the image of Figure 3 (and the CreateOrder class sample code) utilize "custId".

A helpful reminder that a user with permissions to access the database tables would have been helpful.

CS Cassell 12/02/05 10:01:30 AM EST

Several of the links are broken. This could be a really good article but ones needs the various links to work correctly.

José D´Andrade 12/01/05 09:11:56 AM EST

Please, think Linux. Think about Linux users when writing articles about developing whatever using:

Eclipse
Apache
Tomcat
MySQL

It is confusing to read about things that perhaps only apply to MS Windows (¨be sure to launch C:\Mysql\winmysqladmin.exe ¨) when the tools are mostly used by Linux people. And, this is not religion.

At least, write referencing both OSs.

José D´Andrade 12/01/05 09:10:40 AM EST

Please, think Linux. Think about Linux users when writing articles about developing whatever using:

Eclipse
Apache
Tomcat
MySQL

It is confusing to read about things that perhaps only apply to MS Windows (¨be sure to launch C:\Mysql\winmysqladmin.exe ¨) when the tools are mostly used by Linux people. And, this is not religion.

At least, write referencing both OSs.

Bill Dornbush 11/29/05 03:16:26 PM EST

Where is the source code for the article? I can't find any for this issue of the magazine at java.sys-con.com

@ThingsExpo Stories
Operational Hadoop and the Lambda Architecture for Streaming Data Apache Hadoop is emerging as a distributed platform for handling large and fast incoming streams of data. Predictive maintenance, supply chain optimization, and Internet-of-Things analysis are examples where Hadoop provides the scalable storage, processing, and analytics platform to gain meaningful insights from granular data that is typically only valuable from a large-scale, aggregate view. One architecture useful for capturing and analyzing streaming data is the Lambda Architecture, representing a model of how to analyze rea...
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.
The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
SYS-CON Events announced today that Open Data Centers (ODC), a carrier-neutral colocation provider, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Open Data Centers is a carrier-neutral data center operator in New Jersey and New York City offering alternative connectivity options for carriers, service providers and enterprise customers.
The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
PubNub on Monday has announced that it is partnering with IBM to bring its sophisticated real-time data streaming and messaging capabilities to Bluemix, IBM’s cloud development platform. “Today’s app and connected devices require an always-on connection, but building a secure, scalable solution from the ground up is time consuming, resource intensive, and error-prone,” said Todd Greene, CEO of PubNub. “PubNub enables web, mobile and IoT developers building apps on IBM Bluemix to quickly add scalable realtime functionality with minimal effort and cost.”
Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...
With several hundred implementations of IoT-enabled solutions in the past 12 months alone, this session will focus on experience over the art of the possible. Many can only imagine the most advanced telematics platform ever deployed, supporting millions of customers, producing tens of thousands events or GBs per trip, and hundreds of TBs per month. With the ability to support a billion sensor events per second, over 30PB of warm data for analytics, and hundreds of PBs for an data analytics archive, in his session at @ThingsExpo, Jim Kaskade, Vice President and General Manager, Big Data & Ana...
In the consumer IoT, everything is new, and the IT world of bits and bytes holds sway. But industrial and commercial realms encompass operational technology (OT) that has been around for 25 or 50 years. This grittier, pre-IP, more hands-on world has much to gain from Industrial IoT (IIoT) applications and principles. But adding sensors and wireless connectivity won’t work in environments that demand unwavering reliability and performance. In his session at @ThingsExpo, Ron Sege, CEO of Echelon, will discuss how as enterprise IT embraces other IoT-related technology trends, enterprises with i...
When it comes to the Internet of Things, hooking up will get you only so far. If you want customers to commit, you need to go beyond simply connecting products. You need to use the devices themselves to transform how you engage with every customer and how you manage the entire product lifecycle. In his session at @ThingsExpo, Sean Lorenz, Technical Product Manager for Xively at LogMeIn, will show how “product relationship management” can help you leverage your connected devices and the data they generate about customer usage and product performance to deliver extremely compelling and reliabl...
The Internet of Things (IoT) is causing data centers to become radically decentralized and atomized within a new paradigm known as “fog computing.” To support IoT applications, such as connected cars and smart grids, data centers' core functions will be decentralized out to the network's edges and endpoints (aka “fogs”). As this trend takes hold, Big Data analytics platforms will focus on high-volume log analysis (aka “logs”) and rely heavily on cognitive-computing algorithms (aka “cogs”) to make sense of it all.
One of the biggest impacts of the Internet of Things is and will continue to be on data; specifically data volume, management and usage. Companies are scrambling to adapt to this new and unpredictable data reality with legacy infrastructure that cannot handle the speed and volume of data. In his session at @ThingsExpo, Don DeLoach, CEO and president of Infobright, will discuss how companies need to rethink their data infrastructure to participate in the IoT, including: Data storage: Understanding the kinds of data: structured, unstructured, big/small? Analytics: What kinds and how responsiv...
Since 2008 and for the first time in history, more than half of humans live in urban areas, urging cities to become “smart.” Today, cities can leverage the wide availability of smartphones combined with new technologies such as Beacons or NFC to connect their urban furniture and environment to create citizen-first services that improve transportation, way-finding and information delivery. In her session at @ThingsExpo, Laetitia Gazel-Anthoine, CEO of Connecthings, will focus on successful use cases.
Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...
The true value of the Internet of Things (IoT) lies not just in the data, but through the services that protect the data, perform the analysis and present findings in a usable way. With many IoT elements rooted in traditional IT components, Big Data and IoT isn’t just a play for enterprise. In fact, the IoT presents SMBs with the prospect of launching entirely new activities and exploring innovative areas. CompTIA research identifies several areas where IoT is expected to have the greatest impact.
Wearable devices have come of age. The primary applications of wearables so far have been "the Quantified Self" or the tracking of one's fitness and health status. We propose the evolution of wearables into social and emotional communication devices. Our BE(tm) sensor uses light to visualize the skin conductance response. Our sensors are very inexpensive and can be massively distributed to audiences or groups of any size, in order to gauge reactions to performances, video, or any kind of presentation. In her session at @ThingsExpo, Jocelyn Scheirer, CEO & Founder of Bionolux, will discuss ho...
SYS-CON Events announced today that GENBAND, a leading developer of real time communications software solutions, has been named “Silver Sponsor” of SYS-CON's WebRTC Summit, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. The GENBAND team will be on hand to demonstrate their newest product, Kandy. Kandy is a communications Platform-as-a-Service (PaaS) that enables companies to seamlessly integrate more human communications into their Web and mobile applications - creating more engaging experiences for their customers and boosting collaboration and productiv...
Roberto Medrano, Executive Vice President at SOA Software, had reached 30,000 page views on his home page - http://RobertoMedrano.SYS-CON.com/ - on the SYS-CON family of online magazines, which includes Cloud Computing Journal, Internet of Things Journal, Big Data Journal, and SOA World Magazine. He is a recognized executive in the information technology fields of SOA, internet security, governance, and compliance. He has extensive experience with both start-ups and large companies, having been involved at the beginning of four IT industries: EDA, Open Systems, Computer Security and now SOA.
From telemedicine to smart cars, digital homes and industrial monitoring, the explosive growth of IoT has created exciting new business opportunities for real time calls and messaging. In his session at @ThingsExpo, Ivelin Ivanov, CEO and Co-Founder of Telestax, shared some of the new revenue sources that IoT created for Restcomm – the open source telephony platform from Telestax. Ivelin Ivanov is a technology entrepreneur who founded Mobicents, an Open Source VoIP Platform, to help create, deploy, and manage applications integrating voice, video and data. He is the co-founder of TeleStax, a...
The industrial software market has treated data with the mentality of “collect everything now, worry about how to use it later.” We now find ourselves buried in data, with the pervasive connectivity of the (Industrial) Internet of Things only piling on more numbers. There’s too much data and not enough information. In his session at @ThingsExpo, Bob Gates, Global Marketing Director, GE’s Intelligent Platforms business, to discuss how realizing the power of IoT, software developers are now focused on understanding how industrial data can create intelligence for industrial operations. Imagine ...