karolos ignatiadis

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since Nov 15, 2003
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Recent posts by karolos ignatiadis


I have the following problem:

When I execute "java main" a window pops up with the following error:

Microsoft Visual C++ Debug Library

Debug Assertion Failed!

Program: c:\j2sdk1.4.2_09\bin\java.exe
File: app3ds.cpp
Line:32 ASSERT(!afxContextIsDLL); // Should only be called by apps

If I press "Ignore" I then get a "java.lang.UnsatisfiedLinkError: D:\...\Hmi_HITDlg.dll: A
dynamic link library (DLL) initialization routine failed."

If I press "Retry" I get a java.lang.UnsatisfiedLinkError: D:\..Hmi_HITDlg.dll: One or more
arguments are invalid.

What I am actually trying to do is call a C++ function from Java using JNI (JNI code is generated using SWIG).

Here is my C++ function (in HMI_HITDlg.cpp):

float get_LongVel() {
return myInput.Vehicle.LongVel;

This is my JNI code (in HMI_HITDlg_wrap.cxx)

JNIEXPORT jfloat JNICALL Java_Hmi_1HITDlgJNI_get_1LongVel(JNIEnv *jenv, jclass jcls) {
jfloat jresult = 0 ;
float result;

result = (float)get_LongVel();

jresult = (jfloat)result;
return jresult;

This is the code where I am loading the dynamic link library Hmi_HITDlg.dll (contains HMI_HITDlg.cpp and HMI_HITDlg_wrap.cxx
and other necessary files and is made using Visual C++ 6.0, from File->New->Projects->Win32 Dynamic-Link Library) in main.java:



The size of the DLL that I am loading is approx. 2.04MB .

What is going on here? Please help!!
15 years ago
My story is very long and I have asked myself the same question a million times, that is, whether certification helps at all.

All I can say here is that after completing the SCWCD certification (a month ago) I was offered a job to organise and teach Java (and possibly XML) seminars in a local University. There is also the prospect of finding a second job doing some programming with Java.

Hope this helps.


Karolos E Ignatiadis

SCJP1.4, SCWCD, OCA(preparing for PL/SQL), IBM XML(preparing)
As far as I can remember I started preparing for both SCWCD and IBM XML and Related technologies in early March. I am now in the final stages of preparation for the IBM XML exam. Therefore I can say that the whole preparation period for the SCWCD should have been about two months (more time has been devoted to IBM XML up to the date of SCWCD examination).

Also I can honestly say that my CV has received much more attention since the SCWCD entry and I can hardly find time for job interviews! The certification thing certainly attracts employers and headhunters!

But those things are not important, what's important is that GREECE IS EURO 2004 CHAMPIONS ON 4TH JULY, THE KINGS OF EUROPE!!!


Οι θεοί του Ολύμπου ήταν 12, οι σύχρονοι 11
16 years ago



16 years ago
Thank you very much Gian and sorry for the delay in my response. I am just back from holidays and badly sunburned too!!

I didn't use any flashcards creation tool (just the plain old paper type), although I think that Academic Flashcards 3.0 should be a good tool for that purpose, but it's only Shareware and the license expires after 30 days(http://www.tucows.com/preview/202849.html).

By the way has anyone watched the Euro 2004 match today?

Greece 1 - France 0 Hehehehehehehehehe
16 years ago
I gave the exam on Friday and I cleared it with 88%. I didn't manage to score as high as I did with SCJP1.4(93%) but still it is a good result for me as I usually scored only 80%-82% in the mock exams. Also I was preparing for the IBM XML at the same time with SCWCD.

Here is the masterplan:

PHASE 1: Learning
1. SCWCD Exam Study Kit, Hanumant Deshmukh, Jignesh Malavia, Jacquelyn Carter
2. Revision Questions from SCWCD Exam Study Kit
3. Revision Notes (see relevant JavaRanch links)
4. Practicing code specimens(plenty in CD-ROM that comes with SCWCD Exam Study Kit) with Apache Tomcat
5. Copying and pasting the most important DTD elements in a single page(e.g <servlet>....</servlet> etc
6. Same as 4. for the most important functions(just signatures)
7. Creation of many (I mean MANY) flashcards

PHASE 2: Exam Training
1. Free Mock Exams(see latest JavaRanch links)
2. Sybex Java-2 Web Developer Certification Study Guide revision questions, assessment test and practice exam(no chapter reading at all)
3. JWebPlus
4. Creation of many flashcards from this phase also

PHASE 3: Revision
1. Revision with Flashcards to refresh concepts
2. I planned to go through all exams in JWebPlus but I only had time to go through the ones I scored the least
3. Revision of all concepts by going through SCWCD Exam Study Kit again(took 2 whole days) and then going through the Exam Quick Prep provided by SCWCD Exam Study Kit many times

The exam was more difficult than I expected and although I was very good at the Structure and Deployment of the Modern Servlet Web Applications I only scored 50% there!!In the rest I got 100% except from JavaBeans, Design Patterns and Session Management were I got 80%, 75% and 75% respectively.

Going back I think I could have scored more if I practiced more with code, making more examples by myself and see how they work. Code practicing is crucial if you want a very high score. IBM XML is the one to blame here for not having much time for that!!

I would like to thank all the kind and sharing people of JavaRanch, especially Kathy Sierra and Bert Bates for being an inspiration on Java for me. The only reason I didn't get 93% as I did in SCJP1.4 I think is also because I didn't use one of their fabulous books!!I will definitely look for a book for SCBCD from these authors if there is one!!

I wish to share too if that's possible, I haven't share much so far and I know I'll probably go to hell for that!!I have many flashcards for the SCJP1.4 in a word document and I would like to post them in a shared area in JavaRanch or any other available web space. I can also email them to anyone who's interested. Any suggestions welcome.

Know I am not sure of what I want to do next. I have very ambitious plans for CIW JavaScript, Oracle PL/SQL, SCBCD, CIW UML, Websphere or Weblogic, C#, CIW Perl, .NET, Delphi and Flash but obviously I cannot do them all in this lifetime so I have to stick to about 4-5 certifications given that I am already a SCJP1.4, SCWCD and I passed the 1Z0-007 Oracle 9i SQL exam. I was thinkig of doing JavaScript, PL/SQL, SCBCD, Websphere or Weblogic(which is best and is it possible at all by self-studying???)and UML. And if there is still any energy at all in my poor flesh after all of them, possible CIW Perl. Please help, give me some pointers here if you can...

Thank you all!

16 years ago
be confident and stay confident. With Dan's exams and Kathy's & Bert's book the exam should be a walk in the park!

I had similar results with you before I bought and started the JQPlus tests(average for Marcus Green's Mock Exams - 72%, average for Dan Chishlom's Mock Exams(1-19) - 62%) and I scored 93% in the exam.
Doing the JQPlus tests I felt that I increased my percentage by 3%-5%. By the time I was doing the tests most of the questions seemed very familiar because I have done so many free online mock exams.
So the bottomline is that I would advise you to only do the exams if you need the extra 3%-5% that much. No matter how well or bad you did in the Dan's exams it a great resource for revising together with the main points of a good book. Good luck and all the best!!
by the way, does anybody anything about the actual percentage that appears on the report?
Mine says, "There are 58 questions in this exam. You answered 57 questions correctly which gives you a score of 93%"
Is my Maths THAT lousy or is the actual percentage different than the one that appears on the report?
Please post a reply if you know, I still don't know what to put in my CV. CertManager is even more confusing it just says "pass". I know 93% or 98% are the same but a higher mark is more impressive and maybe it will help me to land the job that I am hunting more quickly.
17 years ago
Thank you very much Bert, really honoured to be congratulated from you!
Please keep on writing great books!
17 years ago
Seems that we got the same mark. Many congratulations and all the best with whatever you decide to do next!!
17 years ago
Thank you all very much. Before I forget here's what I did to pass the exam:
PHASE 1: Learning
1. "Sun Certified Programmer & Developer for Java 2", Kathy Sierra & Bert Bates
2. Revision of 1
3. Ebooks (JavaCaps, Cramsession) see JavaRanch's lists for such exam crams
4. Sun Learning Center Tutorials, Sun Java Basic Tutorials 1&2(can download from Sun, not all are relevant just a quick pass)
5. Revision Notes(plenty on the Internet see JavaRanch's lists) & my notes(only about 12 pages)
6. Additional reading for weak areas(I borrowed from a friend the Java 2 Programmer Exam Cram 2, Bill Brodgen, Marcus Green)which is an excellent book for revising and enforcing knowledge already gained.
PHASE 2: Exam Training
1. Mock Exams from "Sun Certified Programmer & Developer for Java 2
2. Free Online Mock Exams(Dan's exams is a MUST, see JavaRanch's list for latest suggestions)
3. e-practice Mock Exam from Sun Learning Centre
4. Commercial Mock Exams (I did JQPlus but Whizlabs is also highly recommended from many people in JavaRanch)
PHASE 3: Revision
1. Flashcards( very useful to have flashcards can create them during Learning, Exam Training or both)
2. Any exams from PHASE 2
3. Revision Notes
4. "Sun Certified Programmer & Developer for Java 2", TWO-MiNUTE DRILLS & SELF TESTS
5. Any step from PHASE 1(if necessary)

I know the above looks like a crazy algorithm but it worked for me!!
- Calculate the time you need and try to stick to your plan, don't just go on without a timeplan it might take forever
- Don't be too hard on yourselves, if you missed hours or days from your plan that's cool, you are not a factory or a robot that's supposed to work up to the last minute. But BE persistent, do not give up when there's something you don't understand. Tenacity pays well here. Also there are always the people of JavaRanch who can help you or just give you a hand
when you fall(plus all the very useful posts, your problem could be already explained there)
- Always be there when you study, not in some tropical beach in Hawaii or Jamaica!! My mind used to wander around the Santorini landscapes but I tried always to concentrate and catch myself if thinking of something else while studying!
- If you want to cut down the cost of the whole certification, try to enroll to the Sun Academic Initiative. In some cases you are eligible to subscribe to this programme just by being a library member etc. The exam voucher also costs about $55 if you are a member.
Here's the address:
Sun Academic Initiative
- I found the 4 pass approach suggested by Kathy Sierra's & Bert Bates's book tremendously helpful and efficient. That is: Pass 1: Cherry pick easy questions first, Pass 2: Complete all questions, Pass 3: Review Marked, Pass 4: Review all, quality check. That's the perfect battle plan!!!
- The night before the exam try not to drink alcohol. It just messes up your mind. Also try not to watch TV, chances are that by watching TV your short term memory will not be at it's best shape for the forthcoming challenge.
- Try to relax before the exam, e.g. listen to a CD you like or whatever works for you and try to focus during the exam.
That's all folks!!

17 years ago
I am sorry for the rude emoticon in my previous message I just don't know how it got there. No offense to anybody or anything!!!
17 years ago
I passed the SCJP 1.4 exam a few hours a go and I still cannot figure out what's my real mark.
The exam was taken through the Pearson's VUE testing system(not Prometric) and my Examination Score Report says:
"Your percentage score was determined by taking the overall number of correct answers divided by the total number of questions.
There are 58 questions in this exam. You answered 57 questions correctly which gives you a score of 93%.
Unfortunately Pearson VUE does not assign Candidate ID's to test takers and my Score Report does not have such an ID(says ID Pending) that I can use to check my test result through Sun's CertManager.
Also I can clearly remember that I answered all 61 questions( and NOT 58 questions, so maybe those extra 3 questions were not to be marked??
Maybe this has something to do that the exam is taken using the Sun Academic Initiative? I researched into this and found out that the exam offered through the Sun Academic Initiative(212-035) is exactly the same as 310-035 in style and format.
Anyhow, I'm still very happy with the result I don't want to be sound greedy or something but I gotta know what my mark is. There is still a lot of effort to be made from my side in the areas of SCWCD and XML certification.
Many thanks to all JavaRanchers for their constant support and help, being a member of JavaRanch is like being a member of a big family!
Also special thanks to Kathy's and Bert's book for writing the most enjoyable and informative book I have read so far(and I have read many!!!).
You are the best!!

17 years ago
Could anybody who has knowledge of this matter post a reply?
I am just three days before the exam and I encountered more questions on JQPlusv4 that ask for implementation details for Collection class!!I usually miss such questions(about 3 questions which means about 5% less!)
I know that Exam Objectives do not explicitly mention anything about implementation details for Collection classes but does this necessarily mean that the exam won't have such questions??