debug GWT on tomcat using eclipse - eclipse

I'm using GWT 2.4 and have a ton of code already written. I understand the Jetty server that comes with the GWT plugin has very tight control over the jars that can be used in a project to mimic app engine as closely as possible. I need to deploy to tomcat 7. I modified my project in eclipse and "blessed" it as a dynamic web project so I can export...WAR and upload it to my QA and production tomcat.
I need help with getting the app to run (and debug) on an embedded tomcat (like an honest dynamic web project would). I already have tomcat setup in eclipse and I have my CAS server web app deployed to it.
I've ready tons of either old or confusing posts here and elsewhere. Basically, I'm looking for the same debugging environment I would get with the packaged Jetty server, but on my own tomcat configured with WTP in eclipse...so I can mimic my production environment (just like Jetty mimics app engine)
any help is appreciated.

It should probably a little bit easier, but it's possible. Here's how I do it:
1. Setting up the web server
Using the JavaEE edition of Eclipse, I set up the Tomcat 7.0 server adapter, and define an environment in Preferences > Server > Runtime Environments
File > New > Project... > Web/Dynamic Web Project
Select the target runtime I set up in the first step
Important: In Context Root, enter /
I create an HTML file and a Servlet, and then try running the setup using Debug As > Debug On Server
2. Adding the GWT code server
Project > Properties > Google > Web Toolkit > Use Google Web Toolkit
Important: I always need to change the order in the Java Build Path (Project > Properties > Java Build Path > Order and Export), see http://code.google.com/p/google-web-toolkit/issues/detail?id=4479 - gwt-dev.jar must be pretty much on top of the path.
Project > Properties > Google > Web Application: War directory = "WebContent", also check "Launch and deploy from this directory"
I create some sample GWT content (I create a sample GWT project, and copy most of it over)
I try to GWT compile the project. This shows me, if I got the build path order right - otherwise, the compiler fails early with "java.lang.NoSuchFieldError: warningThreshold".
Debug As > Web Application - just to create a debug configuration. Stop the debug. Edit the debug configuration (Run > Debug Configurations...), deselect "Run built-in server". Start the debug again.
Now, finally, I can debug both the server and the client part (I still need to click two Debug icons to start both!) I can manage the client side from the "Development Mode" view, and the server side from the "Servers" view. At the end of the day, it works great, and using the "Automatically publish when resources change" feature (Servers view > myServerName > Open > Publishing), sometimes even better than with the integrated Jetty.

At first thought, I don't really see why you would be facing a problem. Perhaps, the way Eclipse is laid out is too confusing and daunting.
On my Eclipse, I had been using the default jetty as the server during GWT debug. However, there were some problems which would not be caught by jetty when deployed on Tomcat or JBoss.
And when I added Tomcat or JBoss instances to Eclipse and added my app to those server instances, the debugging worked straight away. Are you missing one piece of vital, but simple info?
Let me presume that the following would fill in your missing link ...
Locating/adding your server instance:
On Package Explorer (or Project Explorer, either one) in Eclipse, you would see, besides your personal projects, a "servers" project. Under it is are configuration nodes listing all your Tomcat instances.
If you cannot see the "servers" node in Package Explorer, it probably is due to your working set filter. (And if you don't know what working sets are ... I guess you would need to beef up on your dexterity in Eclipse).
If you don't already have a Tomcat instance, you simply right click on the "servers" project to add a new server (Package Explorer -> New -> Server ...). You would be asked the location of your Tomcat home. And your desired port number of the server instance. Of course, you would have to ensure that the port number will not clash with the port used by any other inet operation on your box.
Configuring the port number a 2nd time
On the server instance node in Package Explorer, you would find the file you should edit to set the port number to match the one you specified when creating the new Tomcat instance. If you don't know which file to edit, you would need to read up on the Tomcat version you created to find out which file contains the port number config.
You need to config the port a 2nd time because the 1st time tells Eclipse where and at what port to expect the server instance to be running. The 2nd time is to configure the server instance itself.
Adding your app to the server
However, the nodes in "servers" project only allow you to configure your Tomcat instances. There is yet another view called the "server view" to further configure your tomcat instance. You need to enable Server view from Window->Show View->Server->Servers.
Right click on the server instance in the "Server View" to add your app.
Running debug off the Maven generated target.
There are times you wish to debug the war structure to figure out which jars are missing in the war. And incrementally remove jars from your war to figure out the jars that are already supplied by the server. Since JBoss supplies many of the jars already, you would have to figure out if your development jars are of the versions as those expected by JBoss.
You would create another Eclipse project in your workspace and make an Eclipse folder softlink in your 2nd project to point to the Maven generated target of your first project. And you specify target/{maven generated webapp directory} as the webapp directory of your 2nd project. What I mean by "maven generated webapp directory" is the unzipped intermediate directory generated by Maven (used by Maven to generate the zipped war file).
This is the cleanest way to debug production war if you could faithfully replicate the production tomcat/jboss server on your Eclipse development box.
If you prefer JBoss.
Somehow, JBoss config node is not listed in the "Servers" node in Package/Project Explorers. You would need to go to your JBoss installation directory to edit them.
Remote debugging.
If you wanted to debug the app on your production box, or on a server sitting on another box, you would have to start that tomcat instance under debug. You should read up on that. You have to specify the debug port.
Then in Eclipse, at Run->Debug Configuration->Remote Java Application, you specify the app and the debug port.
The first time you debug, Eclipse "may not know" where the source files are, especially if your app has multiple project dependencies. (Why can't Eclipse search the source files from my list of projects?) Anyway, you have to specify where to find your source files. And then when your debugging traverses into another project dependency, you would have to over-write the location of the source files.
So, voila! That is how I got my debugging working. I advise you to avoid remote debugging as much as possible unless you need to diagnose production problems. Unless you are doing remote debugging, do not attempt to deploy the war to local server, but simply depend on associating the project to the server instance.
Eclipse is too confusing
I know Eclipse is too confusing and you have to wade thro its features. You just have to bear with it. Eclipse menus & views are apparently optimized for plugin-programmer-centric not user-centric.
For example, why would I go to "help" to install new software? I used to expect that "Help->Install new software" to be an instructional manual to installing new software.
It beats (and annoys me) that the Eclipse team did not combine the operations together so that I could add apps to a server instance at Package Explorer. Why not? As a user I would expect to see only a single entry point to configuring my servers.
To alleviate the confusion, I like encouraging people to download and install Springsource's version of Eclipse (STS). It's the same Eclipse, except that STS has the essential parts installed and has a dashboard pointing to compatibly installable plugins. Tomcat is preinstalled as VMware tc Server. And the views are correctly config'd to show the server instances. And the correct workable Eclipse-Maven bridging plugin is pre-installed.

Related

Tomcat and Eclipse vs Intellij

I am working with Intellij but some of my co-workers don't. When I was writing install doc, I realized that Tomcat is not managed the same way on the two IDEs.
Which is a problem considering what happened next when I tried to set up our project on Eclipse.
Basically, on Intellij, you select a Tomcat on your computer and it will literally copy the war into the webapps folder and run the server with everything working fine.
I am not a user of Eclipse so I might have misunderstood something, but I found that when you create a Tomcat server, it will embed the one you gave it to it. Doing that is a bit of an issue when you are working with logback, because usually you set your logs location directly into the Tomcat folder. And in Eclipse you are working out of this folder.
So, I can't run my application because it can't find the location of the logs folder at the fine place.
Is there a way to use Tomcat in Eclipse like Intellij? Or did I just miss something because I am kind of new with Eclipse?
See the FAQ: (1) (2)
I found that when you create a Tomcat server, it will embed the one you gave it to it.
You have to be more specific with your description. How you do things and what do you see. What do you mean by "embed"? What is the actual failure that you are observing with your logging?
There are different ways to do things.
For me by default Eclipse does not embed Tomcat, but runs it as a proper java process. (org.apache.catalina.startup.Bootstrap) You should be able to see it with jconsole and similar tools.
It runs your web application expanded, i.e. without zipping it into a war file. It creates a separate configuration of Tomcat, i.e. runs it with separate CATALINA_HOME and CATALINA_BASE directories (as documented in RUNNING.txt file of Apache Tomcat). The CATALINA_HOME directory stays untouched and CATALINA_BASE directory is ${workspace}/.metadata/.plugins/org.eclipse.wst.server.core/tmp0 etc. A logs directory can be found there.
One known caveat is that java.util.logging is not configured by default (the system properties java.util.logging.manager and others are not set). See "How do I enable the JULI logging" item in the FAQ. -- In the same way you will set any other system properties that you may need.
The default configuration of java.util.logging (as provided by JRE) is to log everything to the console, without creating any files.

Eclipse's Tomcat gives a 404 while the WAR file works-previous solutions don't work

So when I'm running my project through Eclipse's "Run on server" the 'server' doesn't work (when trying the URI http://localhost:8080/simpleapp/ there is an automated 404 Tomcat's webpage), but when compiling and deploying the WAR file through Tomcat's app manager it works fine (the exact same URI gives the response I expected).
How can I systematically solve the issue?
It's important for me to solve it since debugging is a living hell this way right now (can't do a step-by-step debugging,every time that I want to check something I have to re-deploy my project :( ).
I've looked for hours for a solution so I've tried lots of different settings, and the proposed solutions don't work here.
Specifically,when changing the server's configuration in Eclipse to 'use tomcat installation', it doesnt work through eclipse (and the WAR file cannot be undeployed and doesn't work either!),switch location doesn't work either...
More details which are optional but might help:
I have another project where the server through Eclipse does function, I've just used a different Maven archetype this time. When Eclipse's server 'worked' I used jersey-quick start-web app but this time I had to use (org.glassfish.jersey.archetypes:jersey-heroku-webapp (An archetype which contains a quick start Jersey-based web application project capable to run on Heroku)) and added dynamic web module through project facets and as I said now the Eclipse server doesn't work (oh and I've tried to delete the server and reset the configuration too, but no luck).
Try to deploy your WAR using "Add and Remove" from the Servers view instead of using "Run on Server". If the WAR doesn't appear check the Project Facets and ensure that Dynamic Web module is enabled.

How to deploy a REST (Jersey) serivce on Tomcat in Eclipse

I was looking for a way to deploy a Jersey webservice on Tomcat using eclipse, but I didn't find simple or clear examples, and I would like to know the steps to follow or an example to make the job done.
If you haven't done so already, download a tomcat installation and use it to set up a server runtime in eclipse:
Then open your server configuration by double clicking on its name in the Servers tab.
Under 'Modules' click 'Add Web Module...' to add your project and specify the path for deployment (if you don't see your project in list of modules or if the button is disabled, make sure your project has the 'Dynamic Web Module' facet, you can check by right-clicking on your project > Properties > Project Facets)
Under 'Overview' you can further set up your tomcat environment (by setting up port values, timeouts etc..)

JBoss server does not get changes

Eclipse Indigo
Version: Indigo Service Release 1
Build id: 20110916-0149
JBoss 6.1.Final
I have a server which i have configured with some support, but it has broken down.
Broken down means, even tough i;
- stop the server,
- clean and build projects in workspace,
- and clean the server and publish from scratch,
- and start the server again
it responds like it has yesterday's code. I made lots of change but server seems not to be aware of changes.
If you have an advise on this issue, please provide.
Thanks
Try autodeploying your .war or .ear file manually, not using the Eclipse JBoss connector (which sometimes breaks down and acts strangely). Just copy the file to the autodeploy dir (for JBoss 6 i believe this is /server/default/deploy), check the JBoss's logs/console to see that your file is currently deployed, then delete it from there, and again check that the JBoss console confirms succesfully undeploying that application.
Now, that Eclipse JBoss connector is convenient because it lets you quickly deploy, debug, etc (even tho it has it's bugs). You can however to several things to simulate it's behavious without actually using it:
simplest one: Use Jetty: http://irc.codehaus.org/display/JETTY/Downloading+Jetty. Comes as Eclipse plugn, maven plugin, stand alone server. Jetty 8 supports servlet 3.0 so it's up to date. Deploying and debugging is fast and easy and it actually works (I use this a lot). Only downer: doesn't have EJB container.
Use tomcat 7 (stand alone install) and the Eclipse sysdeo plugin: http://www.eclipsetotale.com/tomcatPlugin.html. Allows for seamless deployment/debugging as you'd do with a Java SE application inside Eclipse. Again, the downer is no EJB container
If you really wanna use JBoss, try the following:
start in in debug mode all the time by adding this to your run.bat:
set JAVA_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=n %JAVA_OPTS%
make your "target" project folder (the one where either Eclipse or Maven (whichever you use)) to be something like [jboss root]\server\default\deploy\myAppName
Start a "Remote Java application" debug session from Eclipse on the port 8787.
With all this the project should deploy any changes you make on the fly, and stop at whatever breakpoints you have when execution reaches them. It's not awesome, as sometimes certain changes will not be taken into account (eg: if you modify the body of a method in a Java class it will be hot-deployed. If you add a new method it will not).

Configure project in eclipse so that it ends up in the tomcat "common" class loader

I have two tomcat web applications that need to share information using a singleton. I have already made it work by placing the jared classes in the tomcat common directory. Each webapp then gets the same copy of the singleton. What I would like to do is to integrate this behavior within eclipse. I would like the common classes to be a single project that gets incorporated into the tomcat common class loader every time I start the tomcat server within eclipse. Anyone knows how to configure eclipse to do this?
May be one possibility could be to extend the tomcat class loader in order for that class loader to search in other directories than WEB-INF/lib, this by:
Extending org.apache.catalina.loader.WebappClassLoader and override the findClassInternal method.
Configuring Tomcat to use the extended classloader.
This is done in the appropriate webapp configuration file under the Tomcat conf/Catalina/hostname path with the following element:
...
Then in eclipse, you could set your common project on the "Required projects on the build path", which makes it part of the classpath.
That means your extended classloader must be able to look for other classe:
either in a fixed pre-defined path
or in a pre-defined path within the classpath.
Not tested myself, but may be that can give you a lead on this issue.
A much simpler solution is proposed by noselasd in the comments, taking advantage of the GlobalNamingResources Component of Tomcat.
However, the FAQ does mentions:
When you create a new Tomcat server in Eclipse, the New Server wizard assumes it is not safe to affect the current behavior of the Tomcat installation that this new server will use.
WTP is able to avoid affecting the behavior of the installed Tomcat by using Tomcat's ability to run multiple server instances from a single installation. Thus, the default configuration for each new Tomcat sever you create will be a new server instance of the Tomcat installation associated with the Tomcat runtime selected in the wizard.
If you expect the new Tomcat server in Eclipse to run the same instance that the default batch files in your Tomcat installation run, you will likely be surprised when the Tomcat server in Eclipse doesn't behave as expected.
The Tomcat server configuration can be changed so that it does run the same instance as your Tomcat installation.
You will find here how to modify the server.xml in WTP.
I've managed to get it working. Here is what I did:
Created a common project in the eclipse workspace.
Created the two web applications, called first and second, that should share the common project.
When the web applications are created a Servers project is created with the tomcat configuration.
Change catalina.properties inside the Servers project and add the line shared.loader=/path-to-workspace/common/bin.
This works perfectly for development. Every time a new build is created everything is in sync. For deployment You need to convert the common project into a common.jar and place it in ${catalina.home}/lib.