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.
Related
I'm having trouble wrapping my head around how to use servlets properly
I've set up a postgres database, and downloaded a JDBC driver for it.
What I want to have is my webpages post to the servlet, and the servlet get info from the database. I understand how to code everything (eg add library for driver, open connections, execute queries), but I think I'm lacking knowledge in how to set up the file structure.
I have the postgresql database running on pgAdmin. Do I also need to have a server running to make the servlets work as well? Can't I just make a web.xml file that maps to the servlets, and open the webpages to use the website? If I run the project through an IDE with a server running (glassfish) everything works. If I close the IDE and go to open the webpages on my browser again, I get 404's whenever I submit to a servlet.
Can someone give me a bit of guidance on the big picture of how everything is supposed to interact (with details on servers please). I've been searching the web and I havent found anything that explains the big picture very well.
Thanks
A Java web application is a set of files obeying a well-defined structure, and which can be packaged in a war file.
This web application is deployed into a server (also called container), which understands the file structure, listens to HTTP requests, and calls the appropriate servlet of the appropriate deployed web application when it receives one.
And of course, if you shut down the server, nothing listens to the HTTP requests anymore, so you won't get any response.
You could read the Java EE tutorial for more explanations.
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.
I'm writing a Lift application which works fine when I'm testing locally with Jetty. However, when I deploy the application to a remote server with Tomcat running, my redirects stop working. I deploy my application with a war, myapplicationname.war and it's accessible via http://myserver:8080/myapplicationname/
This is what I have in my code:
S.redirectTo("/manage/project", () => S.notice("Your entry has been saved"))
Instead of being redirected to http://myserver:8080/myapplicationname/manage/project I'm redirected to http://myserver:8080/myapplicationname/myapplicationname/manage/project (myapplicationname doubled). Everything else (Menus, SHtml.links etc) work just fine on the remote server. What could be the problem?
This is almost certainly something to do with Lift's interpretation of the context. You dont say what version of Lift or Tomcat you're using, but I would recommend looking at LiftRules.calculateContextPath. That is the rule function that is used throughout Lift's internals to determine how to undertake the redirect & rewriting.
Failing that, you may well have something screwy in your Tomcat setup. Alas, you simply dont provide enough information to debug this.
If you have Lift 2.4-M3 version, problem mentioned above might be associated with this Lift's open issue
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 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/