Java EE EAR debugging with source tree - eclipse

I've recently been assigned to work on a Java project. I don't have a lot of experience with this kind of development, so I'm kind of struggling.
The typical development process for this project is:
Make changes in source code
Run ant build script to create EAR
Deploy EAR to development server (Weblogic 12.1.2)
Run application and see if the changes you've made fix the issue you're working on.
So, I am taking it as my personal goal to make it possible to do local development, so debugging will actually work and such.
After spending time googling and playing around, I'm able to get at least part of the way, but am having trouble towards the end of the process.
I've tried some different methods to try to get things working.
First, I checked out the source code via Eclipse, so it shows up as a Project and is correctly linked to subversion. I can bring the build.xml file into the Ant view and build the target I'm interested in. This gives me a EAR file (and a WAR file). But when I try to debug the project, via the right-click on the project and selecting Debug As... I get three options: Java Applet, Java Application, JUnit Test.
If I choose Java Applet, I then get a Select Java Applet popup. After choosing what I think is the right applet I get Errors exist in required project(s), Proceed with launch? If I proceed, I get an Applet Viewer and a bajillion errors and nothing else. If I don't proceed, then the Error log fills up with a bajillion other errors.
If I choose Java Application I get a list of a bunch of different entries, none of which is what I'm trying to debug.
So, after trying all that, I decided to see if I could just import the generated EAR file and debug that way. So, I went through the Import wizard, found the EAR file that I build via Ant. After selecting that and proceeding through the dialog, I get two projects in my Project Explorer: the application (we'll call it AppX) and the AppX_WEB project.
Now, if I select the AppX project and choose Debug As, I get Debug On Server, which is promising. The Console tells me that the server is listening on 127.0.0.1:7001, and the built-in browser actually starts bringing up the page. So I'm feeling pretty good about all that.
The problem is, though, I don't know how to attach that EAR file to the source tree that I've got already so I can actually step through the code.
And going deeper, how do I set it up so that I can develop in my source tree and have them automatically propagated into the EAR file and redeployed?
Or, even better, can I get this working without having to build the EAR file and deploy it? Meaning, can I just run straight from the source tree?
Anyway, any help you can give will be much appreciated.
Thanks!

You can start your server in debug mode then attach eclipse to the running instance and debug it.
For this enable debug port in jvm configurations on your server and launch remote application debugging in eclipse.

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.

Running PlayN in HTML DevMode

I'd like to be able to run my PlayN project as a Web Application in DevMode, so that I can use a quick browser refresh to see code changes without having to recompile. From what I'm reading on the wiki and on this question it sounds like that should be possible.
I set up my project using: mvn archetype:generate -DarchetypeGroupId=com.googlecode.playn -DarchetypeArtifactId=playn-archetype -DarchetypeVersion=1.7 and importing the pom.xml into eclipse.
Here's what I can do:
Run from eclipse as a Java Application
Start the server using Maven command line: mvn -Phtml integration-test
While I can do most of my programming in Java and occasionally do the long build to test HTML, I'd love to be able to modify the code while testing HTML without recompiling.
By default, the option to run as a Web Application doesn't show up. I've tried going into the project's properties and checking the "Use Google App Engine" and "Use Google Web Toolkit" options, which creates the "Run As Web Application" option, but when I do so I get "Could not find any host pages in project XXX".
I then attempt to set a WAR directory under Properties->Google-Web Application. However, the closest thing to a WAR in the project is "src/main/webapp". I've tried using that, and I get the error: "The archive: /myproject-assets/src/main/java which is referenced by the classpath, does not exist."
I have the feeling I'm going about this all wrong. Can anyone point me in the right direction? Is what I'm doing even supposed to be possible? Thanks!
It is possible, but just know that in dev mode, playn runs very slow.
I don't know how to do this with eclipse, but with intelli IDEA, you do the following:
you need to create a module with a war artifact (to run as a server)
add the correct gwt libraries so that you can run gwt dev mode server with the aforementioned war module.
choose a GAE server (or, any gwt compatible server actually, this will be the server that runs the aformentioned war module).
run it! see this screenshot http://screencast.com/t/qK4JKvF33V
when you change code, the gwt devmode server should detect it, and automatically recompile (not sure if this needs to be in debug mode - i don't think it does).
you can try doing it via the command line, not sure if works, but this is what intellij runs (i've taken out the intellij specific bits out):
java -cp CLASSPATH_WITH_GAE_DEV_TOOLS_AND_GWT_DEV_TOOLS com.google.gwt.dev.DevMode
-war /path/to/war
-startupUrl Roborally.html com.yourgame.YourGwtEntryModule
-server com.google.appengine.tools.development.gwt.AppEngineLauncher

debug GWT on tomcat using 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.

GWT Post build command in Eclipse

I am starting getting used to Eclipse, but I have much more experience with Visual Studio. In Visual Studio it is possible to run auto commands after the build has finished.
Now I am creating a GWT project and several other projects at once in one solution (or workspace) in Eclipse. Some files which are compiled with the GWT project needs to be copied to another location when they have been compiled. I am currently doing this manually and would like to do it automatically. I am not doing it often, since the project works fine in debug mode (...?gwt.codesvr=localhost:9997).
But where is the location for executing a post build command for a GWT project in eclipse? Is it possible?
Just open project properties, choose 'Builders' item and click on 'New...' button.
Good question! I'm using Eclipse since about 2003, and I remember that I also wanted a functionality like that back then. However, I got so used to using ant for any serious build, that I completely forgot about it.
There is some useful ant integration in Eclipse (e.g. the ant view), and if you create your GWT project with webAppCreator you already get a few good ant targets you can build upon.
It would still be nice sometimes to have something more GUI-like to do simple multi-step builds with Eclipse. I haven't found anything like that yet, but it's absolutely possible that it exists, especially as a plugin.