Welcome!

Eclipse Authors: Pat Romanski, Elizabeth White, Liz McMillan, David H Deans, JP Morgenthal

Related Topics: Eclipse

Eclipse: Article

Eclipse Special: Remote Debugging Tomcat & JBoss Apps with Eclipse

So without further ado here is how I use Tomcat, JBoss, and Eclipse to build and debug applications

To view our full selection of recent Eclipse stories click here

Over the last several weeks I've received a few questions about remote debugging with Eclipse. I posted about this on my other blog back in February here but with not enough info for others to follow.

If you go look at that blog entry you will see that I looked into 'in eclipse' debugging but did not find it satisfactory.

So without further ado here is how I use Tomcat, JBoss, and Eclipse to build and debug applications.

Whichever platform you are using (Tomcat or JBoss) you need to start them with the JPDA debugging enabled. For Tomcat this is very easy. In the $CATALINA_HOME/bin directory there is a script catalina.sh. If you provide the arguments 'jpda start' tomcat will startup and listen on port 8000 for a debugger connection.

With JBoss its only slightly more complicated. Basically you need to specify the JAVA_OPTS to have java start up listening for debugger connections. I typically copy the $JBOSS_HOME/bin/run.sh to $JBOSS_HOME/bin/run-debug.sh but you can just as easily setup the JAVA_OPTS environment variable and use the run.sh script.

The value of JAVA_OPTS needs have -Xdebug -Xrunjdwp:server=y, transport=dt_socket,address=4142, suspend=n specified.

So this is what is going on with this argument list

  • Xdebug == start the jvm and listen for debugging connections
  • Xrunjdwp... == the info on how to connect to do remote debugging
  • server=y == start in server mode (i.e. wait for connections, don't go out looking to connect
  • transport=dt_socked == use sockets, this works (I think) only on unix (I'm on a mac), on Windows you have to use shared memory via the transport=dt_shmem argument instead. I'm fairly sure this works but its been a while since I tried it on Windows. YMMV. Here is the official info on the connection arguments
  • address=4142 == the port to connect to or the shared mem address to use
  • suspend=n == don't wait for a debugger to tell you what to do, go ahead and launch

Once you have JBoss or Tomcat running and listening for debugging connections you are good to go for connecting with Eclipse

The first thing you need to do is create a 'debug launch configuration' by bringing up the launch configuration editor. Figure 1 shows the menu item to invoke to make that happen

When the launch config editor appears select 'Remote Java Application' from the 'Configurations:' selection list on the left hand side then click the 'New' button. Figure 2 shows the defaults that appear for me after hitting the 'New' button.

Since it defaults to the Tomcat port leave the port number set to 8000, if yours is different then change it to 8000. Notice also that you can specify the host to connect to. If you have access to the port and the process is running on another machine then you can debug the process remotely. This works out really well for those situations where it works fine in your local env but not in the test env. I usually rename the configuration (it defaults to the name of the project for me) to 'Debug Tomcat' or something like that.

The other options (Source & Common) can be ignored for now. If you have not already launched tomcat in debug mode do so now on the command line with $CATALINA_HOME/bin/catalina.sh jpda start. When its launched go back to the Eclipe launch configuration editor and hit the 'Debug' button. If you are not auto switched to the'Debug' perspective go there now. You should see a 'Debug View' that looks a lot like Figure 3.

Your code should be directly below the Debug View if you have the default layout still in place. If so go there and set a break point in one of your servlets' service methods (or any other code that is being executed in Tomcat, like a struts action or whatever) and then go to the Web browser and tickle the code that you have a break point set in. Notice that Eclipse suspends Tomcat at the breakpoint, comes to the front and lets you debug your program. Everything works just as if you were debugging locally.

Everything works the same within JBoss once you get it started with the debugging turned on. Keep in mind that you must set the port to match (in the above discussion of JAVA_OPTS it is set to 4142). So you need to create a new Debug launch configuration and specify 4142 as the port. Then you can debug your EJBs.

If you'd like to know more about this or you are having trouble making it work feel free to comment or send me an email.

Happy Debugging!

More Stories By Bill Dudney

Bill Dudney is Editor-in-Chief of Eclipse Developer's Journal and serves too as JDJ's Eclipse editor. He is a Practice Leader with Virtuas Solutions and has been doing Java development since late 1996 after he downloaded his first copy of the JDK. Prior to Virtuas, Bill worked for InLine Software on the UML bridge that tied UML Models in Rational Rose and later XMI to the InLine suite of tools. Prior to getting hooked on Java he built software on NeXTStep (precursor to Apple's OSX). He has roughly 15 years of distributed software development experience starting at NASA building software to manage the mass properties of the Space Shuttle.

Comments (32)

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.


IoT & Smart Cities Stories
AI and machine learning disruption for Enterprises started happening in the areas such as IT operations management (ITOPs) and Cloud management and SaaS apps. In 2019 CIOs will see disruptive solutions for Cloud & Devops, AI/ML driven IT Ops and Cloud Ops. Customers want AI-driven multi-cloud operations for monitoring, detection, prevention of disruptions. Disruptions cause revenue loss, unhappy users, impacts brand reputation etc.
Atmosera delivers modern cloud services that maximize the advantages of cloud-based infrastructures. Offering private, hybrid, and public cloud solutions, Atmosera works closely with customers to engineer, deploy, and operate cloud architectures with advanced services that deliver strategic business outcomes. Atmosera's expertise simplifies the process of cloud transformation and our 20+ years of experience managing complex IT environments provides our customers with the confidence and trust tha...
At CloudEXPO Silicon Valley, June 24-26, 2019, Digital Transformation (DX) is a major focus with expanded DevOpsSUMMIT and FinTechEXPO programs within the DXWorldEXPO agenda. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of business. Only 12% still survive. Similar percentages are found throug...
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, discussed how Dice leverages data insights and tools to help both tech professionals and recruiters better understand how skills relate to each other and which skills are in high demand using interactive visualizations and salary indicator tools to maximize earning potential. Manish Dixit is VP of Product and Engineering at Dice. As the leader of the Product, Engineering and Data Sciences team at D...
As you know, enterprise IT conversation over the past year have often centered upon the open-source Kubernetes container orchestration system. In fact, Kubernetes has emerged as the key technology -- and even primary platform -- of cloud migrations for a wide variety of organizations. Kubernetes is critical to forward-looking enterprises that continue to push their IT infrastructures toward maximum functionality, scalability, and flexibility. As they do so, IT professionals are also embr...
The Japan External Trade Organization (JETRO) is a non-profit organization that provides business support services to companies expanding to Japan. With the support of JETRO's dedicated staff, clients can incorporate their business; receive visa, immigration, and HR support; find dedicated office space; identify local government subsidies; get tailored market studies; and more.
At CloudEXPO Silicon Valley, June 24-26, 2019, Digital Transformation (DX) is a major focus with expanded DevOpsSUMMIT and FinTechEXPO programs within the DXWorldEXPO agenda. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of business. Only 12% still survive. Similar percentages are found throug...
As you know, enterprise IT conversation over the past year have often centered upon the open-source Kubernetes container orchestration system. In fact, Kubernetes has emerged as the key technology -- and even primary platform -- of cloud migrations for a wide variety of organizations. Kubernetes is critical to forward-looking enterprises that continue to push their IT infrastructures toward maximum functionality, scalability, and flexibility.
Today's workforce is trading their cubicles and corporate desktops in favor of an any-location, any-device work style. And as digital natives make up more and more of the modern workforce, the appetite for user-friendly, cloud-based services grows. The center of work is shifting to the user and to the cloud. But managing a proliferation of SaaS, web, and mobile apps running on any number of clouds and devices is unwieldy and increases security risks. Steve Wilson, Citrix Vice President of Cloud,...
When Enterprises started adopting Hadoop-based Big Data environments over the last ten years, they were mainly on-premise deployments. Organizations would spin up and manage large Hadoop clusters, where they would funnel exabytes or petabytes of unstructured data.However, over the last few years the economics of maintaining this enormous infrastructure compared with the elastic scalability of viable cloud options has changed this equation. The growth of cloud storage, cloud-managed big data e...