I seem to recall seeing someone attach a Java debugger to a compiled / deployed GWT application in a screencast. Is this possible? I'm finding some sparse mentions of configuring a special "debug module" that extends your regular one, but details are thin.
Thanks!
You can use dev mode to debug deployed application BUT you will debug using your current code (from eclipse) instead of the deployed one. How? Just like with debugging on localhost, change url and it's done:
http://your-test-or-production-or-sth-server.com/application.html?gwt.codesvr=localhost:9997
This will let you debug real problems happening in the environment with real data and previously deployed gwt services (or ejb beans and other stuff). Just remember, that you are not debugging compiled gwt code, you're debugging the code you have used when starting dev mode. You can of course debug the version of the application deployed to the server (by checking out that version from your source control system), but there is no way to actually debug javascript in java (1) that I know of.
(1) - http://code.google.com/p/chromedevtools/
Related
The project I work at is quite specific. We use GWT with SAP backend. We run the Dev Mode using the following configuration (as program arguments; I run the project directly using IntelliJ IDEA)
-noserver -logLevel INFO -startupUrl http://server-url:8000/aaa -whitelist ^http[:][/][/]server-url[.]eu[:]8000/aaa com.company.project.main.Main
Note, we didn't use a local server (-noserver).
After familiarizing myself with the Super Dev Mode, I understood, that it works similar to GWT Web Mode, i.e. it compiles JavaScript (the folder to compile to can be specified) and then runs the code server with that script hosted.
Due to the specifics of the project, the compiled JavaScript is deployed to the remote server using maven via WebDav. So simply specifying -workDir as a parameter will not deploy the scripts on the remote server. Nor can we run (at least at the moment) a Java server on the server-url address.
Can we use the Super Dev Mode in this situation?
Yes you can.
EDIT 2016-11-27: I built a devserver that can use -launcherDir-style SuperDevMode without the need to write to the server, by using a webpack-like proxy: https://github.com/tbroyer/gwt-devserver
EDIT: there are a few issues re. deferred-binding properties. The recommended use of SDM (since GWT 2.7) is to use -launcherDir which means using a local server.
SuperDevMode works much like DevMode with -noserver, which means you have to deploy your app at least once to your server. In the case of SuperDevMode, it means you have to compile and deploy with the xsiframe linker and devModeRedirectEnabled property set to true.
Then you run SuperDevMode on your machine, create your bookmarklets if not done already, load your app from the remote server and click the Dev Mode On bookmarklet.
This will store something in the browser's sessionStorage so that reloading the page will now load the permutation from the SuperDevMode running on your machine rather than the remote server.
More info about how SuperDevMode works: http://blog.ltgt.net/how-does-gwts-super-dev-mode-work/
For now, I see only one possible solution, which is to run the gwt-codeserver.jar somehow on the SAP server (with the address, say, http://server-url:8000/bbb) and write a servlet, that will redirect all requests to http://server-url:8000/aaa. However, this is not very easy to implement. The SAP server has "tricky" authentication mechanism, where user first sees the logon page and then they are redirected to a generated session-specific URL.
Other ideas are very welcome.
On integrating a library on server side of my gwt app (maven, gwt 2.4) the development/hosted mode stopped working. The app works fine if deployed or run with "gwt:run" and all unit tests and integration tests pass as before.
If i start development mode (run/debug as web application) from Eclipse the develpoment mode view pops up but nothing else happens. normally the console should show some output but console keeps empty. So i don't even have a hint whats going wrong.
Can someone give some advice where to look / what to do to get at least a hint what's wrong?
if i check out the revision before integrating the library the development mode works! - at the moment i add the dependency (only adding not using it) it stops working.
Background about library i added (don't know if my problem relates to this):I had some problem on integrating the library. the library uses eclipse birt charting engine. This engine has a dependency to Apache derby db, this conflicted with another library. i solved this by excluding the derby dependency via maven. the second problem was a "command line too long" error on unit test - this was solved by updating the maven-surefire-plugin.
The Problem was hard but the solution is simple: With Java 7 it is working!
The problem could be reproduced on 2 of 3 machines. The machine without the problem is the only one that uses java 7. So i installed java 7 on my machine and linked eclipse to it - now hosted mode (from eclipse) works again :-).
I'm developing an application using the Vaadin framework in Eclipse. I'm using the Tomcat v6.0 servlet and run the application in the Eclipse Web Browser. A problem I've been having though is to have recent changes show in the browser when I test the application.
No matter how many times I restart Tomcat, clean all published resources and restart the Eclipse Web Browser the changes still won't take effect. The changes seem to take effect randomly where time is the biggest factor, which is of great frustration when developing...
So my question is if anyone else has noticed this problem and have any ideas of how to solve it, if there is a configuration I can do or if I'm missing a step in the restart which blocks the changes from taking effect..?
Any help would be greatly appreciated!
In Vaadin most of the code runs in the server and is contained in normal Java files. There are three levels of resource/class changes:
The runtime "hot code replacement". If running Tomcat in debug mode some Java class changes can be published without redeploying the web application. However, if the Tomcat is configured to "auto publish" (check your server settings in Eclipse), the redeployment is automatically done whenever classes change and this causes full context reload and sessions serialization (see #2) . Hot code replacement can be enhanced using tools like JRebel.
Web application deployment. This is essentially deploying a new war file to the server. Causes the previous version to be undeployed and deploys the new version of all classes and resources. Sometimes there are some resources left in the servers work directory or classes are not reloaded, in which case the server restart (#3) is needed.
Server restart. This makes the whole JVM to reload and all the classes and web applications are also reloaded. Still cleaning the work directory separately is needed to make sure everything is reloaded.
In addition to this there is the client-side part of Vaadin (essentially a JavaScript compiled with GWT), which is treated as a static resource by Tomcat. If you modify the client-side Java code the GWT is used to recompile the JavaScript. Deployment should be simply file copying. The browsers cache the generated HTML/JS files, but GWT includes mechanism to avoid this.
You should first try to change the server settings for automatic publishing and see if that helps. Also, I've noticed that different Tomcat version behave differently. This is unfortunate, but the only thing you can do is to try to find the versions/set-up that works for you.
Just to make sure: you have been adding ?restartApplication in the URL to force application to restart on page reload, haven't you?
We have a GWT application which draws some resources from a separate servlet via async javascript. In production this poses no problems as both the producer servlet and the consumer GWT app will reside on the same server, however for development I can't find a way to make this happen as we are head to head with the Same Origin Policy.
As a temporary solution I have the servlet running on Tomcat, and I compile and deploy the GWT app to that same Tomcat instance - this of course works, and it does allow me to attach Eclipse for debugging. However there is the slight problem of the 40 second or so build time for each modification.
We would like to be able to debug via GWT's hosted mode w/ OOPHM - can anybody see a way for us to do this?
Thanks all!
you could use the -noserver option of gwt dev mode, which lets you run your server code with any servlet container.
Maybe you can deploy the producer servlet to Jetty.
http://www.enavigo.com/2008/08/29/deploying-a-web-application-to-jetty/
I think the Jetty home most reside somewhere in the Eclipse directories. A simple file search might help.
Good luck!
If you need just a servlet, why not define it in web.xml and start dev mode as usual?
I'm trying to call a web service in my back end java code when it's
running in hosted mode. Everything loads fine, the GWT RPC call works
and I can see it on the server, then as soon as it tries to call an
external web service (using jax-ws) the jetty falls over with a
Internal Server Error (500).
I have cranked the log all the way up to
ALL but I still don't see any stack traces or cause for this error. I just get one line about the 500 Error with the request header and response.
Does anyone know if the internal jetty keeps a log file somewhere, or
how I can go about debugging what's wrong?
I'm running GWT 1.7 on OS X 10.6.1
Edit: I know that I can use the -noserver option, but I'm genuinely interested in finding out where this thing lives!
From the documentation:
You can also use a real production
server while debugging in hosted mode.
This can be useful if you are adding
GWT to an existing application, or if
your server-side requirements have
become more than the embedded web
server can handle. See this article on
how to use an external server in
hosted mode.
So the simplest solution would be to use the -noserver option and use your own Java server - much less limitations that way, without any drawbacks (that I know of).
If you are using the Google Plugin for Eclipse, it's easily set up in the properties of the project. Detailed information on configuration can be found on the official site.
Edit: you could try bypassing the Hosted Mode TreeLogger, as described here: http://blog.kornr.net/index.php/2009/01/27/gently-asking-the-gwt-hosted-mode-to-not):
Just create a file called
"commons-logging.properties" at the
root of your classpath, and add the
following line:
[to use the Log4j backend]
org.apache.commons.logging.Log=org.apache.commons.logging.impl.Log4JLogger
[to use the JDK14 backend]
org.apache.commons.logging.Log=org.apache.commons.logging.impl.Jdk14Logger
[to use the SimpleLog backend]
org.apache.commons.logging.Log=org.apache.commons.logging.impl.SimpleLog
Edit2: the trunk of GWT now also supports the -logfile parameter to enable file logging, but it probably won't help in this case, since the problem lies in the way the Hosted Mode treats the exceptions, not the way it presents them.