I have a jar package that I wrote using netbeans. This package is called from other java file. The jar calls a webservice and is supposed to do something with it. Now everything works fine locally. I compiled the files and locally and uploaded them to the server and when I run it, I get the "Service could not be initialized".I am not sure how to debug this. I am pretty new to java. What is the best approach here to solve the issue?
I would start by implementing logging (I like log4J) in your project so you can get some better details of what is actually going wrong. This will be very useful not only now but in the future as things go wrong (they inevitably will) you will be able to solve them based on how good of a job you did logging what is happening in your application. Right now it sounds like an error is bubbling up and you're not getting much detail about it. Logging should help you determine not only what went wrong but where it happened and what the application was doing at the time.
Try this short introduction to log4j to get started.
Related
I have a Rails 3.2.13 application written in JRuby (1.7.12). I'm developing on Mac OS X 10.10 (though the problem was also evident on 10.9). I have both JDK 1.6 and 1.7 installed. I'm serving the application via torquebox 3.1.1.
If I start the application connecting to my local postgres database, I have no issues. But I need to debug a problem that requires connecting to Oracle. I then switch my adapter to oracle-enhanced and making sure I have ojdbc6.jar and ojdbc7.jar in $JRUBY_HOME/lib. When I start the application via torquebox, I get errors like this:
14:47:58,242 ERROR [org.torquebox.core.runtime] (pool-8-thread-1) Error during execution: ENV['RAILS_ROOT']=RACK_ROOT
ENV['RAILS_ENV']=RACK_ENV
require %q(org/torquebox/web/rails/boot)
: org.jruby.exceptions.RaiseException: (NoMethodError) undefined method `blame_file!' forjava.lang.StackOverflowError:Java::JavaLang::StackOverflowError
I realize the blame_file! error is a separate thing. The StackOverflowError that's the cause of that error is what I care about. It's getting into a failing loop when trying to load necessary files, like rails/boot in this case.
However! When I run "rails console" it works fine and I can load data from the database.
I'm convinced as a result of being able to load the console that this is a problem with torquebox somehow, but I don't know what, nor how to fix it.
Is there any helps anyone can give me? Has anyone seen something like this before? Thanks.
(Edit, I found a locally cached copy of ojdbc7.jar in the app, which explains my original errors with 1.6. I've edited this post to reflect the current situation.)
Try looking at https://github.com/jruby/jruby/issues/976 to work around the blame_file problem and then hopefully you'll get a more useful error message.
Maybe then you'll get something be able to diagnose something similar to:
Error while loading java Class in Jruby application
I got some help on irc.freenode.net/#torquebox. After some confusion about the stack output vs. my stack size, it was suggested that I scale that back some. I set it from 4096m (yes, I realize now that that's ridiculous) to 2048k, and it works.
We don't know why Java crapped out in this specific way, but the end result is that with a smaller stack size, it works now.
We are using Tomcat to deploy our Vaadin-Application. No problems there.
What we would like to do, though, is to execute java-code without redeploying our application. For example: we would like to give the end-user the possibility to add code to our program. So every time a button is pressed the end-user code gets executed as well. (e.g. add extra logging functionality, inform a different user via mail….).
It would also be fine, if the end-user could only use certain classes/methods. e.g.:
this.sendMail(“abc#yxz.com”)
Is this possible? I would appreciate it if anyone could give me a starting point where to look.
Thanks in advance,
Stephanie
I would have a look at BeanShell. This is used in a number of IDEs to add code in running programs.
before asking, please understand that my english is not good.
I'm using Class.forName(...) class in a servlet programming. when I access the servlet, I get a row of detailed controller information from Database indicating which controller to use.
This is Class.forName(...) I coded:
Class c = Class.forName(row.getControllerInfo);
c.newInstance();
This works fine, but there's a problem, i'm using Eclipse. The problem is that when I modified the Controller file, the changed contents were not applied to the server.,,.
Probably the easiest way is not to support dynamic loading. Much better to achieve something like dynamic update by supporting multiple servers. For development, you could get around redeploy delays by using JRebel (there might be others).
If you really do want dynamic loading of classes then the answer is "class loaders". I suggest having a look at those, and come back with any specific questions.
If I understood your problem true,
When you change any file of your project, you must deploy your project to server. If you use server from eclipse, republish may solve your problem.
have you tried clean - re-built and then deploying your application?
I am validating my login form. I have created a validation.xml, added the plugin in struts-config.xml, created ApplicationResource.properties file etc. I have done all the necessary things for validation frame work, my application is also running without errors but it is not validating the data. I have rechecked many times. Please anyone tell me where should I check for probable errors.
Thanks
If as you say, the application is running without errors and your data is not validated, then I think that the validator plugin isn't picked up by your application. That could occur if your login form is not extending ValidatorForm but your plain ActionForm. Are you extending ValidatorForm?
Recheck your code against a Struts validator guide. Even if you already did that, there is still something you might have missed or misunderstood.
Have a colleague or friend look at it. Someone with a fresh clean perspective might notice something you missed because you stared to long at your own code.
If that is not possible you can always delete everything (that is to be read as: save current solution somewhere then get a clean copy from source control) and start from scratch. If then it works, you can compare with what you saved from your initial solution and spot the difference.
I have a rather complex J2EE app I don't have any documentation for and I am trying to get it to run.
I have gotten the ant build script to compile a EAR file that contains a WAR file, but this application even though I get "successfully deployed" on weblogic console is still not working.
There are many required jars missing from the EAR file, hence I get errors about missing classes on the console log when I deploy the app. Sometimes even after I check a particular class is there I still get the error.
What is a best way to debug and get this application running?
Is there any shortcuts in J2EE/Java to "find all dependencies", apps anybody knows to analyze code and find dependencies or anything like that?
Is there any shortcuts in J2EE/Java to "find all dependencies", apps anybody knows to analyze code and find dependencies or anything like that?
Do you mean a compiler? I'm actually semi serious here (even if the compiler won't give you the name of a missing JAR). Indeed, if you are compiling that application successfully with Ant, then you likely have all dependencies required at compile time (you may need more of them at runtime but, well, you'll need to execute the code to identify them). Maybe you just need to add more of them in the EAR during the packaging. Or maybe you need to add more dependencies at the app server classpath level.
In both case, search engines like jarFinder.com or Docjar.com or Jarhoo.com might help you to identify missing JARs and to solve your ClassNotFoundException or NoClassDefFoundError.
You should actually give readers more details about the missing classes, I'm sure people will be able to give you some hints and point you in the right direction.
I know of no easy way to deal with this. If the application provides an ant task build the EAR then the result should be a self-contained deployable application EAR. It is possible that the EAR requires extra libraries to be added to some class path, without documentation it's really hard to know what.
This phrase is, I guess, at the heart of the problem: "Sometimes even after I check a particular class is there I still get the error." Exactly what do you mean?
You are getting a class not found error but you can see the class in the EAR file? If that's the case then things are really difficult, and may well be some kind of classloader issue. I don't know WebLogic at all, but in WebSphere when deploying an application you have a choice of whether to give precedence to JARs in the EAR or to the same JAR in WebSphere itself. Some Applications demand one or the other setting. If there's anything like that in WebLogic then this may be your problem.
Another possible problem is that the app may depend on infrastructure libraries (Eg. XML parsers) that are supplied by WebLogic, but expects a different version that is supplied with the WebLogic version you are using.
Without documentation that the app is supported on the version of WebLogic you are using, I fear you're fighting a long, hard (or even a losing) battle.
I'd assume you managed to get this application put together and compiled in an IDE, maybe Eclipse. Why not simply put all the Jars that you had available at build time, into the EAR?
If you're having to debug this by trial and error, you can look at the list of missing classes and figure out which jars they belong to by Googling for the class names, or maybe you can find them in your IDE too.
If you have a lot of trouble identifying some classes, post the class names (or the error messages) here and someone should be able to tell you where to find the Jar it belongs in.
If you are able to successfully build and deploy the app, but still getting the errors about missing classes, probably some of the jar classes are called through reflection. You may want to search for reflection API calls in the Project through your IDE.
These calls may be something like,
"Class cls = Class.forName(..); cls.newInstance()."
Sometimes even after I check a
particular class is there I still get
the error.
This may be a deployment issue. check the classpath. Some of the jars may be missing from the Classpath.
Is there any shortcuts in J2EE/Java to
"find all dependencies", apps anybody
knows to analyze code and find
dependencies or anything like that?
I'd start by having another go at getting documentation ... or help ... from the original developers, if you can find them. [IMO, people who develop / provide software without any documentation deserve to be bugged incessantly by people asking silly questions.] But I guess you've already tried that.
Then there are the jarfinder.com and other services as mentioned in another answer. (New to me!)
If that fails, I'd try doing a Google search on the FQNs. The chances are that if the missing classes are part of a commonly used library you will hit the Javadocs ... or a posting from someone else with a similar problem to yours.
If the "Google it" approach fails, use the clues in the package naming for the missing classes to try and find where they come from. If they follow the Sun recommendations, the names should map to a company or (real or pseudo-) organization that you can locate by a web search.