Java

26-Mar-12 3:41

A firewall with Java...

Well, simple said: this is impossible.
Java programs are running in a Java Runtime Environment (JRE). That is kind of like a "container", which makes it pretty independent, but also limits it's possibilities.

A firewall needs to filter ALL sockets, all connections to the "outer world". Java would need some connection to the system resources that are capable to do so. But unfortunately is this not standard in Java and only to be reached by using some special libraries like JNI and so, which are also limited in it's possibilities.

But to give you a hook for a good project:

Take a look here: http://mindprod.com/project/projects.html[^]

and also talk to your teacher. The project should not be too big, so you can accomplish it in time.

regards Torsten
When I'm not working

ontology

RORY1723-Mar-12 12:22

RORY17

23-Mar-12 12:22

Can anyone know how to import owl files on eclipse??? Sigh | :sigh:

Re: ontology

jschell23-Mar-12 14:15

jschell

23-Mar-12 14:15

Probably help if you defined "owl" and "import".

But in terms of the java keyword 'import' it isn't used with "files". So if that is at all related then it is impossible.

Re: ontology

RORY1724-Mar-12 22:54

RORY17

24-Mar-12 22:54

i already import owl files in eclipse but i want to call this file in eclipse through code?? (i want to access ontology in eclipse)

Re: ontology

TorstenH.26-Mar-12 0:24

Application gives a java.lang.OutOfMemoryError when run from CLI

26-Mar-12 0:24

ontology on eclipse with jena[^]

asking once should be enough.

regards Torsten
When I'm not working

Bill.Moo22-Mar-12 4:48

Bill.Moo

22-Mar-12 4:48

Hello,

I have a java application written using the Eclipse IDE and when I run it from within the IDE all works as expected. However, if I run the same application from the command line then it fails while executing:

Java

java.lang.OutOfMemoryError: Java heap space
at com.sun.org.apache.xerces.internal.dom.DeferredDocumentImpl.createChunk(DeferredDocumentImpl.java:1932)
at com.sun.org.apache.xerces.internal.dom.DeferredDocumentImpl.ensureCapacity(DeferredDocumentImpl.java:1825)
at com.sun.org.apache.xerces.internal.dom.DeferredDocumentImpl.createNode(DeferredDocumentImpl.java:1842)
at com.sun.org.apache.xerces.internal.dom.DeferredDocumentImpl.createDeferredAttribute(DeferredDocumentImpl.java:503)
at com.sun.org.apache.xerces.internal.dom.DeferredDocumentImpl.setDeferredAttribute(DeferredDocumentImpl.java:421)
at com.sun.org.apache.xerces.internal.parsers.AbstractDOMParser.startElement(AbstractDOMParser.java:1075)
at com.sun.org.apache.xerces.internal.parsers.AbstractDOMParser.emptyElement(AbstractDOMParser.java:1103)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1320)       
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2732)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:625)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:819)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:748)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123)
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:239)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:288

The XML file is 14MB in size. Can you one shed some light on this?

--
Moo

Re: Application gives a java.lang.OutOfMemoryError when run from CLI

Nagy Vilmos22-Mar-12 5:45

Nagy Vilmos

22-Mar-12 5:45

Rather then re-type it, just read this[^].

Panic, Chaos, Destruction. My work here is done.
Drink. Get drunk. Fall over - P O'H
OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre
I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer
Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

Re: Application gives a java.lang.OutOfMemoryError when run from CLI

Bill.Moo22-Mar-12 22:10

Bill.Moo

22-Mar-12 22:10

Thank you for the reply but I of course should have mentioned that I have tried this. Not the VisualVM but increasing the usable memory. I can allocate a max of 320m but anything more and I get :

Java

Error occurred during initialization of VM
Could not reserve enough space for object heap
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

But when it does start in this case with 320m I get

Java

#
# A fatal error has been detected by the Java Runtime Environment:
#
# java.lang.OutOfMemoryError: requested 198896 bytes for Chunk::new. Out of swap space?
#
#  Internal Error (allocation.cpp:272), pid=25971, tid=8792264704
#  Error: Chunk::new
#
# JRE version: 7.0
# Java VM: OpenJDK 64-Bit Server VM (20.0-b03 mixed mode bsd-amd64 compressed oops)
# An error report file with more information is saved as:

So I am still a bit confused, but I downloaded the VisualVM and I'll see what it can tell me. The machine is SMP running OpenBSD v5 and has 6GB of memory and 5.9G of available.

--
Moo

Re: Application gives a java.lang.OutOfMemoryError when run from CLI

jschell23-Mar-12 14:20

jschell

23-Mar-12 14:20

Bill.Moo wrote:
I can allocate a max of 320m but anything more and I get ...64-Bit Server VM...OpenBSD v5 and has 6GB

Not sure what the original problem is but the above suggests something is really wrong with your platform and/or however you are attempting to run that.

Re: Application gives a java.lang.OutOfMemoryError when run from CLI

TorstenH.22-Mar-12 21:42

Encryption and Decryption

22-Mar-12 21:42

It is not just a matter of memory that is assigned to the VM.

you need to find your failure!

You have somewhere in there a infinite loop. That one is creating objects / reading data / ...filling up the memory with bits and in the end crashing your application with a heap space failure.

Find that loop! fix it.
There is no other way around it. Debug through your code and find the never ending loop. There is no Exception defined for such a failure, so you need to find that manually.

Good luck and keep us informed whether you'd find it. Coffee and chocolate helps.

regards Torsten
When I'm not working

Savonr Chor18-Mar-12 16:47

Savonr Chor

18-Mar-12 16:47

Hello.
I have same problem with DES and 3DES Algorithms.
Please explain me.
Thank you.

Re: Encryption and Decryption

Bernhard Hiller18-Mar-12 22:39

Bernhard Hiller

18-Mar-12 22:39

Can you explain what your problem is? Are there problems with the "rounds" for encryption/decryption? With the generation of the key from some user input and some salt? ...?

Re: Encryption and Decryption

Savonr Chor20-Mar-12 0:05

Savonr Chor

20-Mar-12 0:05

Can you give me the code of DES or 3DES Algorithms for Encrypt and Decrypt by Java Language.
For Example:
Text | Encryption | Decryption
-------|---------------------|-----------------
1234 | B43B5639030CFE82 | ?

Please Tell me code for solution this problem.

Re: Encryption and Decryption

TorstenH.20-Mar-12 4:43

20-Mar-12 4:43

Tutorials:

DES: http://sanjaal.com/java/186/java-encryption/tutorial-java-des-encryption-and-decryption/[^]

3DES: http://eternusuk.blogspot.de/2008/09/java-triple-des-example.html[^]

Both well explained.

regards Torsten
When I'm not working

crm code development

simbabruno18-Mar-12 4:53

simbabruno

18-Mar-12 4:53

can anyone help me with a detailed CRM code to help me get started

Re: crm code development

Richard MacCutchan18-Mar-12 22:48

Richard MacCutchan

18-Mar-12 22:48

Yet another question that is impossible to answer in a forum like this. Make use of Google and do some research into your subject first.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Re: crm code development

TorstenH.19-Mar-12 20:24

19-Mar-12 20:24

look out for Open Source CRM Systems:

VTiger[^]

SugarCRM[^]

XRMS[^]

They might help you and will give you a good start.
Please regard the copyright (yes there is also some copyright in open Source) before using Open Source for a commercial project.

regards Torsten
When I'm not working

SOS

Boukhezna18-Mar-12 4:09

18-Mar-12 4:09

svp pouvez vous m’aidées a criée un analyseur lexical pour une Css (feuille de style) Svp c'est urgant et merc!!

Boukhezna18-Mar-12 5:10

18-Mar-12 5:10

Svp aidée moi a développé un analyseur lexical d'une feuille de style (Css) Confused | :confused:

Boukhezna18-Mar-12 5:32

18-Mar-12 5:32

Can you help me to créate analyse lexical to Css Confused | :confused:

jschell18-Mar-12 7:33

jschell

18-Mar-12 7:33

Sounds like homework.

And if style sheets in general it is a big job.
And if it for a specific one then you would of course need to post it.

And this of course presumes that "css" is in fact "cascading style sheet"

Boukhezna18-Mar-12 8:02

18-Mar-12 8:02

Dear Jschell
many thanks for your reply I would like to develop an analyzer lexical for style sheets

with regards