Solved

Debugging JNI code...

Posted on 2001-07-12
6
822 Views
Last Modified: 2011-09-20
Hi,

I have written a simple .java file which calls a "native" method implemented in JNI code (c++). The JNI code is trying to open a file and return the file content as a objectArray to the .java code. Something is going wrong in my JNI code and I would like to debug it and step through the JNI code. Can anyone offer me suggestions on how I can debug the code?

I am using Sun's Java 2 runtime/SDK, Forte Standard Edition as the development environment for the Java code. I used Microsoft's Visual Studio to write the JNI/C++ code. All the development work is being done on Microsoft Windows NT 4.0.

Thanks in advance!
0
Comment
Question by:baigmz
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 6

Expert Comment

by:kotan
ID: 6279261
Hi,

In the JNI/C++ code, you can create a log file and write every debug output to it. Then, you can read the log file.

Regards,
kotan
0
 

Expert Comment

by:matchz
ID: 6279282
If you run your java code under command line, you can debug your native code with printf. You will see your debug statements on console.
0
 

Author Comment

by:baigmz
ID: 6279286
I am doing this already. (ie., printing to the command shell). I was wondering it there is a way to some how attach to the JNI call from a debugger.
0
SharePoint Admin?

Enable Your Employees To Focus On The Core With Intuitive Onscreen Guidance That is With You At The Moment of Need.

 

Accepted Solution

by:
matchz earned 75 total points
ID: 6279309
If your native code is developed under VC, you can enable the VC debugger.
For example, you set a breakpoint at some lines in your code. Then, you set the java executable in VC -> Project -> Executable for debug session.

After you compile DLL and run it, VC will run your java class. Once the java code attach the DLL, your VC should stop at the breakpoint set before.
0
 

Author Comment

by:baigmz
ID: 6284201
My native code was not developed under VC as a VC project but I just used VC's source editor. So there isn't any debugging information that VC will get when I try to step into it.
0
 
LVL 1

Expert Comment

by:Moondancer
ID: 6904938
ADMINISTRATION WILL BE CONTACTING YOU SHORTLY.  Moderators Computer101 or Netminder will return to finalize these if still open in seven days.  Please post closing recommendations before that time.

Question(s) below appears to have been abandoned. Your options are:
 
1. Accept a Comment As Answer (use the button next to the Expert's name).
2. Close the question if the information was not useful to you, but may help others. You must tell the participants why you wish to do this, and allow for Expert response.  This choice will include a refund to you, and will move this question to our PAQ (Previously Asked Question) database.  If you found information outside this question thread, please add it.
3. Ask Community Support to help split points between participating experts, or just comment here with details and we'll respond with the process.
4. Delete the question (if it has no potential value for others).
   --> Post comments for expert of your intention to delete and why
   --> You cannot delete a question with comments, special handling by a Moderator is required.

For special handling needs, please post a zero point question in the link below and include the URL (question QID/link) that it regards with details.
http://www.experts-exchange.com/jsp/qList.jsp?ta=commspt
 
Please click the Help Desk link on the left for Member Guidelines, Member Agreement and the Question/Answer process for further information, if needed.  http://www.experts-exchange.com/jsp/cmtyHelpDesk.jsp

Click you Member Profile to view your question history and keep them all current with updates as the collaboration effort continues, to track all your open and locked questions at this site.  If you are an EE Pro user, use the Power Search option to find them.  Anytime you have questions which are LOCKED with a Proposed Answer but does not serve your needs, please reject it and add comments as to why.  In addition, when you do grade the question, if the grade is less than an A, please add a comment as to why.  This helps all involved, as well as future persons who may access this item in the future to seek help.

To view your open questions, please click the following link(s) and keep them all current with updates.
http://www.experts-exchange.com/questions/Q.11501898.html
http://www.experts-exchange.com/questions/Q.20004188.html
http://www.experts-exchange.com/questions/Q.20106152.html
http://www.experts-exchange.com/questions/Q.11359277.html
http://www.experts-exchange.com/questions/Q.20150126.html
http://www.experts-exchange.com/questions/Q.20150740.html
http://www.experts-exchange.com/questions/Q.20151616.html
http://www.experts-exchange.com/questions/Q.20161911.html


To view your locked questions, please click the following link(s) and evaluate the proposed answer.
http://www.experts-exchange.com/questions/Q.20155689.html

PLEASE DO NOT AWARD THE POINTS TO ME.  
 
------------>  EXPERTS:  Please leave any comments regarding your closing recommendations if this item remains inactive another seven (7) days.  Also, if you are interested in the cleanup effort, please click this link http://www.experts-exchange.com/jsp/qManageQuestion.jsp?ta=commspt&qid=20274643

Moderators will finalize this question if still open in 7 days, by either moving this to the PAQ (Previously Asked Questions) at zero points, deleting it or awarding expert(s) when recommendations are made, or an independent determination can be made.  Expert input is always appreciated to determine the fair outcome.
 
Thank you everyone.
 
Moondancer
Moderator @ Experts Exchange

P.S.  For any year 2000 questions, special attention is needed to ensure the first correct response is awarded, since they are not in the comment date order, but rather in Member ID order.
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Java exception bubble up 2 26
iterator/ListIterator approach 17 66
add projects t working set in maven 2 64
Eclipse with various Java releases 7 84
INTRODUCTION Working with files is a moderately common task in Java.  For most projects hard coding the file names, using parameters in configuration files, or using command-line arguments is sufficient.   However, when your application has vi…
For beginner Java programmers or at least those new to the Eclipse IDE, the following tutorial will show some (four) ways in which you can import your Java projects to your Eclipse workbench. Introduction While learning Java can be done with…
Viewers learn about the “for” loop and how it works in Java. By comparing it to the while loop learned before, viewers can make the transition easily. You will learn about the formatting of the for loop as we write a program that prints even numbers…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
Suggested Courses

738 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question