Java

Re: How can I use relative path in java to read a file ?

30-Jun-10 22:09

ok,Anyway,thanks for your precious Time.
Regards
Yogesh

002comp1-Jul-10 1:43

Re: How can I use relative path in java to read a file ?

1-Jul-10 1:43

Hello Sir
Actually In Windows I am using this code to find the path of running jar file:

File ff =new File(classname.class.getProtectionDomain().getCodeSource().getLocation().getPath());
String jarFilePath = ff.toString();

Now when we hosted the site on Linux server then it is not showing the full path.Its showing only the name of jar file.

Is there way to get full path of jar that is on Linux server.

Thanks & Regards
Yogesh

anand kr25-Aug-10 16:41

anand kr

25-Aug-10 16:41

Yogesh,

If you are talking about reading a resource from relative path with respect to current class, consider using this snippet:-

1) getClass().getResource("url") which will give you URL instance which can be used to read a resource
2) getClass().getResourceAsStream("file or any other resource") which returns an InputStream

anand in dnr

Heap space option -xms and -xmx

002comp22-Jun-10 19:40

22-Jun-10 19:40

Hello Friends

I am creating a Executable jar file using NetBeans.In Project properties under Run I was setting -Xms1024m -Xmx1024m and it was loading file whenever i click on executable jar file.And virtual memory for c drive also setted in paging section from 1024 to 1024.

Now,I want to load a big file and this executable jar is not working.So,I increase virtual memry first to 2048 to 2048 and then in my project properties I setted to -Xms2048m -Xmx2048m but it is not loading.Do I need to make any other changes to load any big file?

Any Ideas guys.
Thanks In Advance.
Regards
Yogesh

Cedric Moonen22-Jun-10 20:22

Cedric Moonen

22-Jun-10 20:22

First thing to do is verify what the problem is, not trying to make assumptions. Did you get an exception ? If yes, copy the stack trace here so that we can have a look. If you don't have enough memory, you should get a memory exception.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

002comp22-Jun-10 20:53

22-Jun-10 20:53

Hello Sir
It is giving error:
Exception in Thread :java.lang.outofmemoryerror :java heap space.

i setted virtal memory to 4096m
And in Netbeans isetted to -Xms2048m -Xmx2048m

Thanks For ur Reply
Regards
Yogesh

David Skelly22-Jun-10 22:33

22-Jun-10 22:33

The first thing to be aware of is that if you are running under Windows, you won't be able to use much more than 1Gb of memory for your Java heap space (certainly true for 32 bit, may be different for 64 bit Windows). The reason is that the Sun JVM requires heap memory to be allocated contiguously (in other words, in one big continuous block of memory). Because of the way Windows loads DLLs into memory, Windows can't normally allocate contiguous blocks of memory bigger than roughly 1 gig (off the top of my head the figure that springs to mind is 1.2Gb but that may be wrong). You can do things like shuffling DLLs around but even then you don't get a lot more and it's probably not worth the effort. Things may be different with 64 bit Windows, I don't know because I've not worked with it very much yet. Things may also be different with other JVMs (I used to use JRockit 5 years ago with WebLogic and that was the same at the time, but I believe that now it no longer requires contiguous memory and so does not suffer from this problem.)

But I would turn this question around: what are you doing that is blowing so much memory so quickly? It sounds to me as if there is something amiss here and instead of throwing more memory at the problem, maybe you could reconsider your design?

002comp22-Jun-10 22:53

Re: Heap space option -xms and -xmx (More Detailed way)

22-Jun-10 22:53

Hello David Sir
Actually the design demands for this type of memory requirement.I have to load a file dynamically with initialisation whose size is around 3.5MB.
But If I load file around 1mb then its working.So to load heavy file I increased the heap space to 2048 then it is not running even thru netBeans,error comes like

Could not create the Java virtual machine.
Error occurred during initialization of VM
Could not reserve enough space for object heap
Java Result: 1

Thanks For ur reply.
Any Ideas?
Regards
Yogesh

002comp23-Jun-10 0:56

Re: Heap space option -xms and -xmx (More Detailed way)

23-Jun-10 0:56

Any Other Ideas Guys??????
I think i made it very confusing.let me Explain u in better way.

The Simple thing is that When I set Heap Space -Xms1024m -Xmx1024 then its working fine. But As I increased to -Xms2048m -Xmx2048 then when I try to run thru NetBeans even It gives me the Error:

run:
Error occurred during initialization of VM
Could not create the Java virtual machine.
Could not reserve enough space for object heap
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)

What do i Need to change to increase Heap Space.

And If I run thru batch file in which I specify
java -Xms512m -Xmx1024m -jar sample.jar

Thanks & Regards
Yogesh

David Skelly23-Jun-10 1:45

Re: Heap space option -xms and -xmx (More Detailed way) [modified]

23-Jun-10 1:45

Re-read my earlier post. On a Win32 platform, you will not be able to allocate more than about 1.2Gb for the heap size.

Question: What do I need to change to increase heap size?
Answer: The operating system

You say that you are having a problem loading a 3.5Mb file into 1Gb of heap space. Something is not right there. What are you doing with this file that is causing it to consume so much memory?

002comp23-Jun-10 2:00

Re: Heap space option -xms and -xmx (More Detailed way)

23-Jun-10 2:00

Ok,i agree with u that I cant give more than 1.2gb heap size on win32 OS But When I run thru Batch file then How it load the same 3.5Mb file?

Yeah,I am reading and parsing that file.

One last Question:What is the difference between running viewer through NetBeans and Running through Directly jar file?How it loads in both way?Any Documentation or If u know tht would b much better.

Thanks & regards
Yogesh

modified on Wednesday, June 23, 2010 8:20 AM

David Skelly23-Jun-10 3:28

Re: Heap space option -xms and -xmx (More Detailed way)

23-Jun-10 3:28

What "viewer" are you talking about and what kind of file is this that you are parsing?

And are you now saying that you can load this file if you run it via a batch file as opposed to running it within NetBeans?

002comp23-Jun-10 17:42

Re: Heap space option -xms and -xmx (More Detailed way)

23-Jun-10 17:42

Hello Sir
Viewer is application that I created to load some 3d files(.obj files).

I think I again confused the scenario or u misunderstood.am sory for that.
Here are the Things:
Now Heap Space is set to -Xms1024m -Xmx1024m.
This one is loading each and every file If I run thru Netbeans.
If I run by directly clicking jar file then its not loading heavy file.
But If I run the same jar file with the help of batch file then it is loading heavy files too.
Now,I want to load heavy files with the click of jar file only.

Thanks & Regards
Yogesh

David Skelly23-Jun-10 22:38

Re: Heap space option -xms and -xmx (More Detailed way)

23-Jun-10 22:38

I understand now, sorry, I was a bit slow on the uptake there.

As far as I am aware, there is no way to set the heap size for executable jar files. If you run the jar by double-clicking, it will use the default heap size for the JVM and you cannot override this in the jar manifest. By the time the jar loads and the manifest is read, the JVM has started and the heap size has been allocated.

So, your options are:

If you can live with launching via a batch file, use javaw to set the -Xms and -Xmx values and run the jar using the -jar switch (this is possibly the most usual way to do it).
If you really must have an executable jar file that you can double click to run, create a small Java program, all that does is to set up the javaw command line with the parameters you want to invoke your main jar, then execute that via Runtime exec (which would work but it's a bit of a hack)
If you don't like that clunky approach, write a little launcher exe in some other language (C, Python, whatever). This is another common way to do things. (I believe this is how NetBeans does it, although I might be wrong there).
Use one of the Java to exe tools (something like launch4j). I have never used any of these, so if you go down that route I cannot advise you which is best, or what the pitfalls are.

002comp23-Jun-10 22:50

Remember password in website

23-Jun-10 22:50

Ok,I will try any one of option from these.
And Thanks For ur time and Help.

Thanks Once Again.
Regards
Yogesh

how to validate date

kirancgi22-Jun-10 8:17

kirancgi

22-Jun-10 8:17

IAM WORKING WITH FTL. my requirement is in my ftl i have one text field , i need to input date into that field and do validate on that by using the f allowing the conditions

format should be yyyy-mm-dd, restrict is not accept other than 10 characters

year: 2000>yyyy<3000

Month: 1>mm<12

Day: 1>dd<<31, based on this display message for wrong entry

where i need to write this conditins, plz send me urgent.

Re: how to validate date

Cedric Moonen22-Jun-10 20:29

Cedric Moonen

22-Jun-10 20:29

Some suggestions first:
1. Please format your message properly because it is almost unreadable. What's with all those spaces everywhere? And please don't write full sentences in uppercase, this is considered rude.
2. People here are not paid to answer questions, so don't ask "plz send me urgent". This is also considered very rude.

Now to your question. What is FTL exactly ?
Anyway, as far as I understood, you have a String containing a date with a specific format, and you would like to check that the format is correct. Am I right ?
If yes, have a look at the SimpleDateFormat[^] class, and its parse method.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

neer117-Jun-10 20:00

neer1

17-Jun-10 20:00

HI ,
I am new to java programming.
We have a website in which login file is to be implemented with "Remember password" functionality. Please guide me how to do it.

Re: Remember password in website

Richard MacCutchan17-Jun-10 22:01

Richard MacCutchan

17-Jun-10 22:01

Here[^] are some potential solutions.

It's time for a new signature.

Encrypt using java and Decrypt with C

Murugan k16-Jun-10 19:43

Murugan k

16-Jun-10 19:43

Hi

I need to encrypt the plan text using AES algorithm in java and decrypt the encrypted text using C.Any please give solution ASAP.

Thanks

Re: Encrypt using java and Decrypt with C

Richard MacCutchan16-Jun-10 21:30

Richard MacCutchan

16-Jun-10 21:30

You could do worse than starting here[^] with your encryption. I'm sure it would not take too long to find the corresponding C code for the decryption phase.

It's time for a new signature.

Substring issue

CodeScribbler15-Jun-10 3:11

CodeScribbler

15-Jun-10 3:11

Hey guys

I have another elementary problem that needs solving. In the program, after you enter your date of birth (e.g. 14/08/1977), the program takes the month out, and gives you a vacation period in that month.

I'm using a long if statement, with a string value assigned to each month. The if statement pretty much goes if, else if, else if...and so on. Am I using the substring method incorrectly?

if(DOB.substring(3,5) == "01")
		{
			System.out.println("Holiday Month: " + month1 + "\n" + "Days: " + DOB.substring(3,5));	
		}

Re: Substring issue

Richard MacCutchan15-Jun-10 21:56

Richard MacCutchan

15-Jun-10 21:56

CodeScribbler wrote:
Am I using the substring method incorrectly?

Not as far as I can see (see here[^]). However your output string will show the month number after the "Days: " field; this may not be what you want.

It's time for a new signature.

Re: Substring issue

David Skelly15-Jun-10 22:35