Welcome!

Weblogic Authors: Michael Bushong, Avi Rosenthal

Related Topics: Weblogic, Eclipse

Weblogic: Article

Configuring Eclipse for Remote Debugging a WebLogic Java Application

A J2EE application deployed in the WebLogic server may be debugged in the Eclipse ID

A J2EE application deployed in the WebLogic server may be debugged in the Eclipse IDE with the remote debugger provided by Eclipse. Without a debugger the error message has to be obtained from the application server error log to debug the application.

With the remote debugger provided by Eclipse, exception breakpoints may be added to the application file to debug. When an application is run in WebLogic and the application generates an error, the application gets suspended and the Eclipse IDE Debug perspective displays the error. In this tutorial we will debug a WebLogic Application Server application in Eclipse.

To debug an application deployed in the WebLogic Server from Eclipse, start the WebLogic Server in debug mode and configure a remote debugging configuration in Eclipse. Next, connect the Eclipse remote debugger to the WebLogic Server and debug applications running in the server. We will develop an example servlet application and deploy the application in WebLogic. First, the servlet is run without any error and subsequently an error is introduced in the servlet to demonstrate the remote debugging feature in Eclipse.

Preliminary Setup
Download the WebLogic 8.1 Application Server and install it. Download the Eclipse 3.0 or Eclipse 3.02 zip file eclipse-SDK-3.0-win32.zip (www.eclipse.org/downloads/index.php) and install it as well.

Developing a WebLogic Application
After installing the WebLogic Server and the Eclipse IDE, develop a servlet application to run and debug in the WebLogic Server. The example servlet application consists of a doGet method, which prints out a String message to the browser. The example servlet, WebLogicServlet.java, is shown in Listing 1.

Create a directory structure for a Web application. Create a WEB-INF directory and a classes directory in the WEB-INF directory. Create a package directory servlets for the example servlet and copy the WebLogicServlet.java file to the servlets directory. Create a web.xml deployment descriptor for the Web application. Copy the web.xml file to the WEB-INF directory. Listing 2 shows the web.xml file.

The example servlet is mapped to URL pattern /weblogic. The structure of the Web application is illustrated below.


/WEB-INF
| |
web.xml classes
|
servlets
|
WebLogicServlet.class
The compiling, packaging, and deploying of the Web application is done in the Eclipse IDE with an Ant build.xml file. Develop an Ant build.xml file that consists of targets to compile the WebLogicServlet.java and package and deploy the webapp.war Web application. Listing 3 shows the build.xml file.

Table 1 shows the properties of the build.xml file. Table 2 shows the file's targets.

Set the debug attribute of the javac task in the build target to true to enable compilation in debug mode. By compiling an application in debug mode the line number, which generates the exception in a WebLogic Server application, gets displayed in the Debug perspective. Create a new project in the Eclipse IDE. Select File>New>Project. The New Project frame gets displayed. In the New Project wizard select Java>Java Project. Click on the Next button. The New Java Project frame gets displayed. In the New Java Project frame specify a Project Name, EclipseWebLogic for example, and click on the Next button. In the Java Settings frame add a source folder to the project with the Add Folder button.

The New Source Folder frame gets displayed. In the New Source Folder frame specify a folder name, src for example. A source folder gets added to the project. A message prompt gets displayed to update the source folder and the output folder. In the New Java Project frame click on the Finish button to create the project. A new project gets added to the Eclipse IDE. Next, select File>Import to import the example servlet source folder to the project. In the Import Select frame select File System and click on the Next button. In the Import File System frame select the src folder and the build.xml file and then click on the Finish button. The servlet source files get added to the project.

Run the build.xml file to compile, package, and deploy the servlet Web application to the WebLogic Server. Right-click on the build.xml file and select Run>Ant Build. The Web application .war file webapp.war gets generated and is deployed to the WebLogic 8.1 Application Server applications directory. Next, start the WebLogic Server with the bin/run script. Invoke the example servlet in a Web browser with the URL http://localhost:7001/webapp/weblogic. The WebLogicServlet runs in the WebLogic Server and the output gets displayed in the browser.

Configuring a Remote Debugging Configuration in Eclipse
To remote debug a WebLogic application in Eclipse start the WebLogic Server in debug mode. Set the WebLogic Server in debug mode by setting the debug options in the startWebLogic batch script file. The debugging provided by WebLogic is based on the Java Platform Debugger Architecture (JPDA). Set the JAVA_OPTS variable as:

set JAVA_OPTS= -Xdebug -Xnoagent
-Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=n %JAVA_OPTS%

Table 3 shows the different debug parameters. For further explanation of the debug settings refer to the JPDA documentation (http://java.sun.com/j2se/1.4.2/docs/guide/jpda/). To demonstrate the remote debugging feature of Eclipse, add an exception to the WebLogicServlet.java file. For example, add a NullPointerException to the WebLogicServlet.java class. Replace

out.println("Eclipse WebLogic Remote Debugging");

with

String str=null;
out.println(str.toString());

Next, configure a debug configuration for the Eclipse project. Select the Debug option in the Debug option list. The Debug frame gets displayed. In the Debug frame select the Remote Java Application node. Right-click on the node and select New. In the Debug configuration frame specify a name for the Debug configuration. Select the project that is to be debugged. Select the EclipseWebLogic project previously created in the Eclipse IDE. Select the default value for Connection Type. In the Connection Properties, specify localhost as the Host and specify the Port as the port that was specified in the startWebLogic batch script of the WebLogic server, 8787. Click on the Apply button. A remote Java application debug configuration gets added.

Next add exception breakpoints to the WebLogicServlet.java file. To demonstrate the remote debug feature of Eclipse a NullPointerException was added to the WebLogicServlet.java file earlier in this section. To add a breakpoint to the servlet class, Select Run>Add Java Exception Breakpoint. In the Add Java Exception Breakpoint frame select the NullPointerException. The NullPointerException breakpoint gets added to the servlet class. If a NullPointerException is generated in the servlet application in the WebLogic Server, the application gets suspended and the Debug perspective of the Eclipse IDE displays the exception.

Remote Debugging a WebLogic Application
After configuring a debug configuration for the example servlet application deployed in the WebLogic Server, we will debug the servlet application in the Eclipse IDE. Create a webapp.war Web application from the modified (with the NullPointerException) WebLogicServlet.class file with the build.xml file as explained in the "Developing a WebLogic Application" section. Start the WebLogic Server. The server starts in debug mode with the debug options specified in the startWebLogic batch file.

Next, select the EclipseDebug debug configuration in the Debug frame. Click on the Debug button to connect the remote debugger to the WebLogic Server. The Eclipse remote debugger gets connected to the WebLogic Server. Select the Debug Perspective button to display the debug perspective of the Eclipse IDE. In the Debug perspective the remote debugger is shown connected to the WebLogic server at localhost, port 8787. Access the WebLogicServlet in the WebLogic Server with the URL http://localhost:7001/webapp/weblogic. Because the servlet has a NullPointerException, the servlet gets suspended with a NullPointerException in the Debug perspective. The line that produced the exception gets displayed.

The line that throws the exception is the out.println(str.toString()); code line. The servlet application may be debugged with the different debug options listed by selecting Run in the Eclipse IDE.

Summary
In this tutorial a WebLogic application was debugged in the Eclipse IDE. A WebLogic application may also be debugged from another IDE such as JDeveloper.

More Stories By Deepak Vohra

Deepak Vohra is a Sun Certified Java 1.4 Programmer and a Web developer.

More Stories By Ajay Vohra

Ajay Vohra is a senior solutions architect with DataSynapse Inc.

Comments (3) 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
Sreedhar 05/18/06 01:15:58 PM EDT

Does any one know how to do remote debug ging in clustered environment??

Neena 03/09/06 05:59:07 PM EST

Do you know how to debug a Clustered WebLogic Environment or where we can get the information on to set up debugging for Cluster?

SYS-CON Brazil News Desk 01/18/06 07:19:38 PM EST

A J2EE application deployed in the WebLogic server may be debugged in the Eclipse IDE with the remote debugger provided by Eclipse. Without a debugger the error message has to be obtained from the application server error log to debug the application.

@ThingsExpo Stories
The 3rd International Internet of @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that its Call for Papers is now open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
Cultural, regulatory, environmental, political and economic (CREPE) conditions over the past decade are creating cross-industry solution spaces that require processes and technologies from both the Internet of Things (IoT), and Data Management and Analytics (DMA). These solution spaces are evolving into Sensor Analytics Ecosystems (SAE) that represent significant new opportunities for organizations of all types. Public Utilities throughout the world, providing electricity, natural gas and water, are pursuing SmartGrid initiatives that represent one of the more mature examples of SAE. We have s...
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, and physical persons. In the IoT vision, every new "thing" - sensor, actuator, data source, data con...
How do APIs and IoT relate? The answer is not as simple as merely adding an API on top of a dumb device, but rather about understanding the architectural patterns for implementing an IoT fabric. There are typically two or three trends: Exposing the device to a management framework Exposing that management framework to a business centric logic Exposing that business layer and data to end users. This last trend is the IoT stack, which involves a new shift in the separation of what stuff happens, where data lives and where the interface lies. For instance, it's a mix of architectural styles ...
The Internet of Things is tied together with a thin strand that is known as time. Coincidentally, at the core of nearly all data analytics is a timestamp. When working with time series data there are a few core principles that everyone should consider, especially across datasets where time is the common boundary. In his session at Internet of @ThingsExpo, Jim Scott, Director of Enterprise Strategy & Architecture at MapR Technologies, discussed single-value, geo-spatial, and log time series data. By focusing on enterprise applications and the data center, he will use OpenTSDB as an example t...
An entirely new security model is needed for the Internet of Things, or is it? Can we save some old and tested controls for this new and different environment? In his session at @ThingsExpo, New York's at the Javits Center, Davi Ottenheimer, EMC Senior Director of Trust, reviewed hands-on lessons with IoT devices and reveal a new risk balance you might not expect. Davi Ottenheimer, EMC Senior Director of Trust, has more than nineteen years' experience managing global security operations and assessments, including a decade of leading incident response and digital forensics. He is co-author of t...
The Internet of Things will greatly expand the opportunities for data collection and new business models driven off of that data. In her session at @ThingsExpo, Esmeralda Swartz, CMO of MetraTech, discussed how for this to be effective you not only need to have infrastructure and operational models capable of utilizing this new phenomenon, but increasingly service providers will need to convince a skeptical public to participate. Get ready to show them the money!
The Internet of Things will put IT to its ultimate test by creating infinite new opportunities to digitize products and services, generate and analyze new data to improve customer satisfaction, and discover new ways to gain a competitive advantage across nearly every industry. In order to help corporate business units to capitalize on the rapidly evolving IoT opportunities, IT must stand up to a new set of challenges. In his session at @ThingsExpo, Jeff Kaplan, Managing Director of THINKstrategies, will examine why IT must finally fulfill its role in support of its SBUs or face a new round of...
One of the biggest challenges when developing connected devices is identifying user value and delivering it through successful user experiences. In his session at Internet of @ThingsExpo, Mike Kuniavsky, Principal Scientist, Innovation Services at PARC, described an IoT-specific approach to user experience design that combines approaches from interaction design, industrial design and service design to create experiences that go beyond simple connected gadgets to create lasting, multi-device experiences grounded in people's real needs and desires.
Enthusiasm for the Internet of Things has reached an all-time high. In 2013 alone, venture capitalists spent more than $1 billion dollars investing in the IoT space. With "smart" appliances and devices, IoT covers wearable smart devices, cloud services to hardware companies. Nest, a Google company, detects temperatures inside homes and automatically adjusts it by tracking its user's habit. These technologies are quickly developing and with it come challenges such as bridging infrastructure gaps, abiding by privacy concerns and making the concept a reality. These challenges can't be addressed w...
The Domain Name Service (DNS) is one of the most important components in networking infrastructure, enabling users and services to access applications by translating URLs (names) into IP addresses (numbers). Because every icon and URL and all embedded content on a website requires a DNS lookup loading complex sites necessitates hundreds of DNS queries. In addition, as more internet-enabled ‘Things' get connected, people will rely on DNS to name and find their fridges, toasters and toilets. According to a recent IDG Research Services Survey this rate of traffic will only grow. What's driving t...
Connected devices and the Internet of Things are getting significant momentum in 2014. In his session at Internet of @ThingsExpo, Jim Hunter, Chief Scientist & Technology Evangelist at Greenwave Systems, examined three key elements that together will drive mass adoption of the IoT before the end of 2015. The first element is the recent advent of robust open source protocols (like AllJoyn and WebRTC) that facilitate M2M communication. The second is broad availability of flexible, cost-effective storage designed to handle the massive surge in back-end data in a world where timely analytics is e...
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.
We are reaching the end of the beginning with WebRTC, and real systems using this technology have begun to appear. One challenge that faces every WebRTC deployment (in some form or another) is identity management. For example, if you have an existing service – possibly built on a variety of different PaaS/SaaS offerings – and you want to add real-time communications you are faced with a challenge relating to user management, authentication, authorization, and validation. Service providers will want to use their existing identities, but these will have credentials already that are (hopefully) i...
"Matrix is an ambitious open standard and implementation that's set up to break down the fragmentation problems that exist in IP messaging and VoIP communication," explained John Woolf, Technical Evangelist at Matrix, in this SYS-CON.tv interview at @ThingsExpo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
P2P RTC will impact the landscape of communications, shifting from traditional telephony style communications models to OTT (Over-The-Top) cloud assisted & PaaS (Platform as a Service) communication services. The P2P shift will impact many areas of our lives, from mobile communication, human interactive web services, RTC and telephony infrastructure, user federation, security and privacy implications, business costs, and scalability. In his session at @ThingsExpo, Robin Raymond, Chief Architect at Hookflash, will walk through the shifting landscape of traditional telephone and voice services ...
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Architect for the Internet of Things and Intelligent Systems at Red Hat, described how to revolutioniz...
Bit6 today issued a challenge to the technology community implementing Web Real Time Communication (WebRTC). To leap beyond WebRTC’s significant limitations and fully leverage its underlying value to accelerate innovation, application developers need to consider the entire communications ecosystem.
The definition of IoT is not new, in fact it’s been around for over a decade. What has changed is the public's awareness that the technology we use on a daily basis has caught up on the vision of an always on, always connected world. If you look into the details of what comprises the IoT, you’ll see that it includes everything from cloud computing, Big Data analytics, “Things,” Web communication, applications, network, storage, etc. It is essentially including everything connected online from hardware to software, or as we like to say, it’s an Internet of many different things. The difference ...
Cloud Expo 2014 TV commercials will feature @ThingsExpo, which was launched in June, 2014 at New York City's Javits Center as the largest 'Internet of Things' event in the world.