Debugging TEchniques

Hello I want a tip on how to debug in JSP. I dont know which line of code I went wrong so what i usually do on Java SE is to print out MARKS but seems like it is different here. Although I can place marks using the scriptlet but what about on class files' methods? I cant do the system.out.println....

That's one of the many reasons that you shouldn't be writing raw Java code in JSP files. There they are not for, JSP's are intended for presentation only. You use taglibs and EL to control the flow and output. Scriptlets in almost all cases just indicate a bad design.
Write Java code in Java classes. Use servlets to control and process requests, use beans to store and transfer data, use utility classes for commonly (re)used static methods, use DAO class to interact with the database.
To debug the Java code, just use an IDE like Eclipse Ganymede and IntelliJ IDEA. A decent IDE has a built-in debugger where in you can follow and control the code execution step by step in realtime.
When JSP's are free of scriptlets and well-written, there is usually no need to debug them.

Similar Messages

Re: Application Crashing - Debugging Techniques?

Hi
If it's crashing when you deploy ,you know where it crashes,
i mean, it
crashes when you do a certain thing on your application
doesn't it? If this is
the case the best thing you cam do is use breakpoints on
flexbuilder debugging
to see what's happening where it crashes. If the application
makes use of
remote services, such as HTTPSEVICE,WEBSERVICE,ETC. perhaps
you have forgotten
to change localhost to the name of your server, or you can be
missing the
crossdomain.xml file on your server.
This is all guessing since i don't know what it says when it
crashes, so if
you want you can send a link to us to see where it crashes or
simply put here
the message it gives.

You misunderstood. It crashes with the Flash player by just
running it outside of the Flex Builder debug state... same
application, same source, same data-locations, etc.. it's not a
deployment issue, it's a stability issue. The application is not
specific to when it crashes... it's very much a stability thing for
my application and Flash. Need debug techniques OUTSIDE of flex
builder. Running the Flex Builder debug state creates a completely
stable application. I can't get it to crash. But it won't be
running this way in the real word.

Debug technique to locate VI which is "hanging"/waiting. Pause button - is not working.

During development I now and then experience that the top-vi simply "hangs". The debug Pause button does not break into the program - it turns red but nothing happens.
I can stop with "Abort button", but then I can't see which vi was stuck in a waiting state - this information is lost.
Are there a way to determine the "state" of sub-vi's in a running application (during development).
like a list:
A.vi : Running
B.vi: Waiting for IO, queue or similar
C.vi: terminated
That would help locating the problem.
Any clever tricks?
Solved!
Go to Solution.

Many thanks for your valuable suggestions. I used your suggestion about the running vi indicator with success:
1) Engage the Pause button in the hung application
2) Open block diagram,
3) Find runnning vi indicator (see image below).
4) Open this vi,
5) Engage its Pause button.
6) locate the running vi arrow.
...and so forth down the tree. Except it only works for vi's having dfebugging enabled.
I found the issue with my application - reported http://forums.ni.com/t5/LabVIEW/Continuous-Measurement-and-Logging-Template-May-hang-up-due-to/td-p/....

Debug technique - how to?

Hi,
I would like to stop processing for debug in a function module, called in a way:
CALL FUNCTION 'My_Function_Module_Name' STARTING NEW TASK '0001'.
Is it possible? If yes - How?
Explanations: Calling FM
...CALL FUNCTION 'ENQUEUE_E_TRDIR'...
from my FM 'My_Function_Module_Name' I achieved starting of only 1 instance of my FM 'My_Function_Module_Name' at a time. If I call it without the addition 'STARTING NEW TASK...' everything behaves as expected, but I'm unable to check if the FM will behave correctly if I call it as expected - with mentioned addition.
Correctly means if there will be only 1 instance at a time.
Any help whould be highly appreciated.
Many thanks in advance.
Regadrs,
Ivaylo Mutafchiev

Well, searching the forum sometimes gives the answer or idea
Ok, I think I found the scenario - it is to use entire power of parallel processing:
CALL .. STARTING NEW TASK PERFORMING someTaskInCaller ON END OF TASK
should do the trick and help me check what's going on in my 'parallel' task.
And I think, it's impossible to debug task started in parallel process, isn't it?
Thanks,
Ivaylo

Debuging techniques

Hi Sdners,
I Am abap learner please give me debuging tips.
Advance wishes
sreenu
Moderator Message: Please search for available information and do not make duplicate post.
Edited by: kishan P on Sep 5, 2010 9:04 PM

please help me to develop my debug techniques

How can I enable remote debug in weblogic to use with Rational RSA IDE?

How can I enable the remote debugging technique so that I can work with my IDE.
I use RSA by IBM as the IDE
What should be the changes in the setdomainenv or startweblogic?
I use 10.3
Please help.. ur help is appreciable...

Hi,
I did not make any console adjustments for debugging on my WebLogic 10.3.2.0 - however I am running in development mode on an "adminServer" (an option during the install)
In the console there is a debug setup page - that seems to have no effect for me (I can always debug) - so either it is a combination of development mode and/or the startWeblogic script from the Eclipse plugin.
However, these debug settings are likely for debugging into the server - you only want to debug your own app code right?
On the console page goto
http://localhost:7001/console/console.portal?_nfpb=true&_pageLabel=ServerDebugPage
servers | AdminServer | configuration-debug | expand weblogic
I see...
"Use this page to define debug settings for this server.
Debug settings for this Server
EnableDisableClear Showing 1 to 2 of 2 Previous Next
Debug Scopes and Attributes State
default Disabled
weblogic Disabled
EnableDisableClear Showing 1 to 2 of 2 Previous Next
Try expanding the whole tree and selecting the root to enable everything.
You will see the following
10-Dec-2009 11:53:46 o'clock AM EST> <Warning> <Management> <BEA-141239> <The non-dynamic attribute DebugAbbreviation on weblogic.management.configuration.ServerDebugMBeanImpl@47a32e1b([base_domain]/Servers[AdminServer]/ServerDebug[AdminServer]) has been changed. This may require redeploying or rebooting configured entities>
<10-Dec-2009 11:53:46 o'clock AM EST> <Warning> <Management> <BEA-141238> <A non-dynamic change has been made which affects the server AdminServer. This server must be rebooted in order to consume this change.>
<10-Dec-2009 11:53:46 o'clock AM EST> <Warning> <netuix> <BEA-423420> <Redirect is executed in begin or refresh action. Redirect url is /console/console.portal?_nfpb=true&_pageLabel=ServerDebugPage.>
When I debug WebLogic 10.3.2.0 from Eclipse 3.5 EE - I see the following in my server startup log which includes the "-Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,address=8453" you mentioned.
Starting WLS with line:
c:\opt\wls10320\JROCKI~1.5-3\bin\java -jrockit -Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,address=8453,server=y,suspend=n -Djava.compiler=NONE -Xms512m -Xmx512m -Dweblogic.Name=AdminServer -Djava.security.policy=C:\opt\wls10320\WLSERV~1.3\server\lib\weblogic.policy -Xverify:none -ea -da:com.bea... -da:javelin... -da:weblogic... -ea:com.bea.wli... -ea:com.bea.broker... -ea:com.bea.sbconsole... -Dplatform.home=C:\opt\wls10320\WLSERV~1.3 -Dwls.home=C:\opt\wls10320\WLSERV~1.3\server -Dweblogic.home=C:\opt\wls10320\WLSERV~1.3\server -Dweblogic.management.discover=true -Dwlw.iterativeDev= -Dwlw.testConsole= -Dwlw.logErrorsToConsole= -Dweblogic.ext.dirs=c:\opt\wls10320\patch_wls1032\profiles\default\sysext_manifest_classpath weblogic.Server
Listening for transport dt_socket at address: 8453
The server process listening on debug portl 8453 ooks like this
Oracle WebLogic Server 11gR1 PatchSet 1 at localhost [Oracle WebLogic Launch Configuration]
     BEA JRockit(R)[localhost:8453]
          Thread [Main Thread] (Running)
          Daemon Thread [Timer-0] (Running)
          Daemon Thread [Timer-1] (Running)
          Daemon Thread [[ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.Default (self-tuning)'] (Running)
          Daemon Thread [weblogic.time.TimeEventGenerator] (Running)
          Daemon Thread [JMAPI event thread] (Running)
          Daemon Thread [weblogic.timers.TimerThread] (Running)
          Daemon Thread [[ACTIVE] ExecuteThread: '1' for queue: 'weblogic.kernel.Default (self-tuning)'] (Running)
          Daemon Thread [Thread-7] (Running)
          Daemon Thread [ExecuteThread: '0' for queue: 'weblogic.socket.Muxer'] (Running)
          Daemon Thread [ExecuteThread: '1' for queue: 'weblogic.socket.Muxer'] (Running)
I hit a breakpoint and see
Daemon Thread [[ACTIVE] ExecuteThread: '13' for queue: 'weblogic.kernel.Default (self-tuning)'] (Suspended (breakpoint at line 56 in ApplicationService))
     ApplicationService_5ptwty_Impl(ApplicationService).insertObjects(List<Cell>) line: 56
     NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]
     NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39
     DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25
     Method.invoke(Object, Object...) line: 597
     AopUtils.invokeJoinpointUsingReflection(Object, Method, Object[]) line: 310
     ReflectiveMethodInvocation.invokeJoinpoint() line: 182
     ReflectiveMethodInvocation.proceed() line: 149
     DelegatingIntroductionInterceptor.doProceed(MethodInvocation) line: 131
     DelegatingIntroductionInterceptor.invoke(MethodInvocation) line: 119
     ReflectiveMethodInvocation.proceed() line: 171
     MethodInvocationVisitorImpl.visit() line: 37
     EnvironmentInterceptorCallbackImpl.callback(MethodInvocationVisitor) line: 55
     EnvironmentInterceptor.invoke(MethodInvocation) line: 50
     ReflectiveMethodInvocation.proceed() line: 171
     ExposeInvocationInterceptor.invoke(MethodInvocation) line: 89
     ReflectiveMethodInvocation.proceed() line: 171
     DelegatingIntroductionInterceptor.doProceed(MethodInvocation) line: 131
     DelegatingIntroductionInterceptor.invoke(MethodInvocation) line: 119
     ReflectiveMethodInvocation.proceed() line: 171
     JdkDynamicAopProxy.invoke(Object, Method, Object[]) line: 204
     $Proxy68.insertObjects(List) line: not available
     ApplicationService_5ptwty_ApplicationServiceLocalImpl.insertObjects(List<Cell>) line: 306
     FrontController.generateGlider(PrintWriter) line: 240
thank you
/michael
http://www.eclipselink.org

Debugging & PHP

I have programmed in ABAP and PHP. Is there a debugging tool for use in PHP where one can step through the program following its path and allowing the program variables values to be displayed? Much like ABAP debugger does. I have heard of Eclipse and PHP plugins, but have not tried it.
Best Regards
Jimmy

Of course there are professional debugging tools for PHP
<commercial_plug>
Zend Studio is a complete IDE for developing and debugging applications -- both locally and remotely against the server. It allows you to do all of the common debugging techniques (variable watching, breakpoints, step throughs, etc.) even if you don't have a copy of the code locally available. You can get more information at:
http://www.zend.com/store/products/zend-studio/
</commercial_plug>
If you are interested in more open source alternatives which are much more difficult to use (in terms of ease of use, etc.) you can also check out XDebug:
http://www.xdebug.org
Hope that helps!
Cheers,
John

One works vi, one doesn't. debugging help.

The attached vi sends a series of xml files to two separate servers. The files configure a camera; turn it on; then, turn it off. It works over and over again. When I add the same code to a more complicated vi, something hangs up. I'm looking for a suggestions, other than running highlighted that might help me debug this.
Thanks
Attachments:
Dazle.vi ‏68 KB

Hi exo,
You may also want to try setting a breakpoint in your code, then step through it. You can set a breakpoint from the Tools Palette (View » Tools Palette). From the Tools Palette, click the Set/Clear Breakpoint button. You can now set breakpoints in the code, which will halt execution. You can then step throught the execution using the Step Into, Step Over, and Step Out of buttons, which are all found on the toolbar. Like Andre said, you can also use Probes to debug your application. These tools are explained in more detail in the link below, please let me know if you have any other questions!
LabVIEW Debugging Techniques
Regards,
Erik J.
Applications Engineer
National Instruments

Debugging a function module

Hi,
Could somebody give me a detailed step by step debugging technique of a ABAP function module
(How to pass the value to a specific function, how values are getting populated in table fields etc.)
Thanks,
Soumen
Moderator message: please search for information and try yourself before asking.
Edited by: Thomas Zloch on Jul 14, 2010 5:04 PM

you want to debug the FM call from a program or you want to debug from SE37 itself..???
if from program.. just keep a break point in CALL FUNCTION line and and debugger reaches there press F5.
if you want directly from SE37.. execute the FM, give the parameters.. then click on EXECUTE Button with text 'Debuggin'

Provide Useful links for WebDynPro (Dynamic Prog,DCs,Theme Mgmnt,Debugging)

Hi Folks,
Kindly provide the useful links/Blogs/Reference for the below mentioned list:
   WD Dynamic Programming
   DC cross reference/inclusion techniques
   NWDI DC/SC configurations and usage
   Portal configuration of pages, worksets, roles
   Theme management at WD and portal levels.
   Programmatically handing JCo connections (open, execute and close)
   WD debugging techniques
Thanks
Kapil Sharma

You want a moccachino with that?...

Hidden, Dynamic parameters in Visual Studio web test - debugging

Hello! I am trying to debug a web test in Visual Studio and I'm running into the issue of incorrectly bound dynamic parameters.
Here is the error I am getting:
Request failed: Context parameter '$HIDDEN1.j_id71:_link_hidden_' not found in test context
I have looked at many blogs and websites that tell you how to fix this bug. (http://blogs.msdn.com/b/edglas/archive/2010/03/24/web-test-authoring-and-debugging-techniques-for-visual-studio-2010.aspx) However the websites haven't helped, my error is slightly
different from the one they outline.
This website in particular tells me how to find the place where the parameter is defined earlier in the code, but in my case this parameter never seems to have been defined. I can't figure out what extraction rule to use (if any).
Let me know if you have any suggestions/useful websites I can look at! Also let me know if you need more information. Thanks in advance!
-Danielle

Hello Jack,
Thank you for your detailed response. I had already gone through the first blog you recommended to no avail, but the second one seems to be leading me more in the right direction.
I have a few more questions for you after looking through this advice.
I added a validation rule like that second blog (http://blogs.msdn.com/b/slumley/archive/2007/11/19/debugging-errors-in-load-test.aspx) says to, and I am seeing that my form parameter "j_id71:_link_hidden_" doesn't exist.
However, I noticed when I right clicked on this parameter name in Response tab of the request that is failing, and selected "Quick Find", it searched for the value that the parameter has been assigned. It found this value in a QueryString parameter
named "_" in the previous request.
After studying my web test, I noticed also that this variable "_" is in many QueryStrings, and it always seems to match these hidden parameters that are not being found in the test context. I believe this query string parameter is the main source
of my issue.
The validation rule I added from that blog post is trying to validate the existence of a Form Post Parameter, however the value I want to extract is in a QueryString parameter. Is there a way to extract a value from Query Strings? I only have found ways
to extract from Form Post Parameters.
What do you recommend? Here are some things I've tried that have failed:
1. I tried renaming the parameter "_" to match the hidden one, that didn't work.
2. I tried creating a new Form Post parameter that matched the Query String parameter in name and value. Furthermore, I tried to use the Validation FormFieldExists rule from the blog to validate that the Form Post Parameter "_" exists, and that
failed. Why isn't it seeing the form field I create?
3. I tried to set the value of j_id71:_link_hidden_ Form Post Parameter in the failing request to {{_}}, so that it finds the value from the correct variable. This didn't work either.
Any other options you can suggest? I know this is a lot of information, I figured the deeper context may help you to help me debug this issue. Thanks again!!
-Danielle
[UPDATE] -- I tried to validate existence of a form post parameter that is obviously there and was there from the beginning, that also failed. Maybe a bug in the validation rule code...
[UPDATE 2] -- I have started to solve my issues by changing the value of these Form Post Parameters to certain QueryStringParam values. By looking in the Properties panel when I've selected a form post parameter that wasn't working, I can change the value
to one of these values using the dropdown. The dropdown menu has about 7 different options named "QueryStringParam11810.ct", for ex. Each param has a different number and ending associated with it, and by trial and error I've been finding matching
QueryStringParams to go with each hidden parameter. So far this is working... Not sure how to choose which value matches in a more specific way besides trial and error.
So I guess this is resolved, although if you have an explanation for all of this that would be very appreciated!

Regarding Debug and Run Settings in Openscript Developer perspective

hi,
I want to debug and run the script.so i inserted the breakpoints. and when i try to debug and run it will ask to select the main type like AESCrypt-oracle.oats.utilties etc. so i don't know which file to select to display my output for the script in Console mode.
What's the exact procedure to debug the script so that i can check where in the script line getting the problem?

Hi
If you like to learn how to use eclipses debuging techniques I suggest you look at this document. However unless you have a lot of costume java code in your script i would not recommend you doing so, from 9.10 you have a debugger in the OpenScript UI, you can just right click on the line that you like to add a Breakpoint and select Add breakpoint, then use the arrow keys to step trough the script.
You can output information to the console by calling this line of code:
getLogger().info("someMessage");
Regards
Alex

SUB:Debuging tips

Hi Sdners,
Please tell me debuging techniques in abap and tel me any deatils.
Thanks & regards
sreenu
*Moderator Message: Please search for available information before posting.
Edited by: kishan P on Sep 5, 2010 9:01 PM

The SB Li've card does 0Hz and up; the Logitech x-530 does 40Hz and up, and may have a tendency to behave badly if fed a signal at 35Hz or below. Turning down the low end will certainly fix this. If you have an EQ tool that will give you a 50Hz slider, that will give you a little more low-end than the 64Hz slider does. A 35Hz slider may work also, but might not slope off the 40-and-below steeply enough to "clean out" the signal.
The long-term danger is that over-driving the sub amp at these low frequencies will burn it up. (If it sounds boomy, it's being over-dri'ven.) The fact it's booming at all suggests this is not an amp with a lot of protection circuitry built into it. Personally, I would not put the sub close to anything flammable...
If you have an old, unused stereo you'll do much better by connecting the SB Li've sub out to an aux input on the old amp, turning its tone control off treble and a little up on bass, and listening through whatever old speaker (preferably 8") you have available. That way the tiny little Logitech amp can dri've the satellites and give you 5 channels, while the bigger older stereo handles the bass.
Cheers,Bob

Newbie: Debugging external code

Hello,
in our project we are using a CIN for certain Algorithms. The annoying thing
there is, that we are not able to debug the code(?). And every SegFault
crashes LabView completely.
Q:
Is there a way to debug the code provided in an lsb?
Is it possible to debug a DLL with VC++? If so, how can I achieve this?
Are there any other debugging techniques not covered above?
Thank you in advance
Olli

I do that regularly, however I create the CIN resource trough the command line. If you create it with the Visual C IDE you will have to make sure you enable the debugging features in the Compile and Link tab of the project settings. This would be mainly:
Compile (C/C++): Optimization: Disable (debug) (/Od)
Linking: Generate debug info (/debug)
In addition you may want to define following makro in your source file:
#ifdef _DEBUG
#define DebugBreaking() {__asm int 3}
#else
#define DebugBreaking()
#endif
and add the DebugBreaking(); call whereever in your source code where you want to break into the debugger. The standard Win32 API DebugBreak() never was able to find my source code to do source code debugging in VC.
Also VC may not be setup automa
tically to catch exceptions and you only get a General Protection fault dialog or a Dr. Watson dialog. There are some registry settings you can make to get VC to be your system debugger and there should be information about how to set that up in your VC documentation or alternatingly on msdn.microsoft.com.
Rolf K
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Could not load file/URL (file not found) error for JNLP file

I am completely baffled in trying to figure out why I am getting the following error for some JNLP files but not others:
Error: could not load file/URL specified: C:\Users\tom\AppData\Local\Temp\javaws2
java.io.FileNotFoundException: C:\Users\tom\AppData\Local\Temp\javaws2 (The system cannot find the file specified)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at java.io.FileInputStream.<init>(Unknown Source)
at com.sun.javaws.jnl.LaunchDescFactory.buildDescriptor(Unknown Source)
at com.sun.javaws.Main.launchApp(Unknown Source)
at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
at com.sun.javaws.Main$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)I have Googled around this forum and elsewhere, and have seen reports that this error is IE-specific, and seems to have something to do with no-cache headers being sent, or with the client browser's cache being full or turned off (which is not my case). I saw the information in the JavaWS FAQ, which recommended turning off security constraints for the JNLP's URI. I tried that, and it didn't help. One of the very baffling things is that I have created several variations of the JNLP file, with varying combinations of jars and property resources, and some combinations always work while other combinations never work. Here's an example:
<jnlp spec="1.0+" codebase="$$codebase">
   <information>
      <title>demo app</title>
      <description>illustrates weird bug</description>
   </information>
   <resources>
      <j2se version="1.5+"/>
      <jar href="randomFile.jar"/>
      <property name="xxx" value="xxxx"/>
      <property name="swing.metalTheme" value="steel"/>
   </resources>
</jnlp>The above file always fails with the error shown at the top of this message. However, if I remove either of the two properties, it works fine. And I have created other variations with lots of properties, some of which work. All of these variations are in the same directory in the war file, served by the exact same servlet (a slightly modified version of the jnlp.sample.servlet.JnlpDownloadServlet provided with JDK 1.6.0_3). Assuming that a no-cache header is the problem, what on earth could be causing some JNLP files to always be served with a no-cache header, while others are never served with a no-cache header?
On a related note, any recommended debugging techniques for seeing what headers are being transmitted? I tried adding a simple check for a "debug=true" parameter in the servlet that causes it to set the content type to "text/plain" instead of JNLP, and that allows me to see (rather than execute) the JNLP XML that's being returned, but it doesn't show me the HTTP headers that are being sent back. If any caching headers are being set, I think it must be being set by the servlet container itself, as it's nothing being set in the servlet code that I can see. So I don't see any way on the server side Java code to output or log the actual HTTP response (or is there?). Any tips in that regard much appreciated.
Edited by: TomC125468 on Aug 19, 2009 1:35 PM

Hi Luca-Sanna,
Thanks for the response. Re browsers, yes, it fails in IE but it succeeds in Firefox. The info on the JavaWS FAQ and other places all seem to indicate that it's an IE issue concerning handling of the cache-control headers.
I should check in my webserver forum (Sun WebServer 7) to see about logging options. Sniffing on the client side is not possible, as my app is required to use HTTPS exclusively, and unfortunately that also precludes a telnet GET request.

Debugging TEchniques

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