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Join Date: Jun 2004
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Practically a Master Poster
Reading Large Files Hi everyone,
I am trying to to read and write large files about 600M.
The thing is when i use the normal FileOutputStream methods an exception gets thrown saying
This is how i am trying to read the file
My computer does have sufficient memory
I tried adding this in the while loop but it does not work and i got the same exception thrown by the JVM again
My question is basically how do i increase the memory programatically
or is there away in which i can read the file without having the above exception thrown by the JVM?
Any help i greatly appreciated
Thank You
Yours Sincerely
Richard West
I am trying to to read and write large files about 600M.
The thing is when i use the normal FileOutputStream methods an exception gets thrown saying
java.lang.OutofMemory
This is how i am trying to read the file
FileOutputStream out = new FileOutputStream("C:/my_life_story.zip");
InputStream in = //an input stream from a socket, etc
int len = 0;
byte[] buffer1 = new byte[1024];
while ((len = in.read(buffer1)) > 0)
{
out.write(buffer1, 0, len);
}
in.close();
out.close();My computer does have sufficient memory
I tried adding this in the while loop but it does not work and i got the same exception thrown by the JVM again
System.gc();
My question is basically how do i increase the memory programatically
or is there away in which i can read the file without having the above exception thrown by the JVM?
Any help i greatly appreciated
Thank You
Yours Sincerely
Richard West
Microsoft uses "One World, One Web, One Program" as a slogan.
Doesn’t that sound like "Ein Volk, Ein Reich, Ein Führer" to you, too?
— Eric S. Raymond
Tell me what type of software do you like and what would you pay for it
http://www.daniweb.com/techtalkforums/thread19660.html
Doesn’t that sound like "Ein Volk, Ein Reich, Ein Führer" to you, too?
— Eric S. Raymond
Tell me what type of software do you like and what would you pay for it
http://www.daniweb.com/techtalkforums/thread19660.html
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Join Date: Nov 2004
Location: Netherlands
Posts: 5,700
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Try flushing the buffer after every write.
The only thing I can think of that's eating up memory here is the outputbuffer. It may not be flushing automatically, causing the JVM to attempt to map the entire output into RAM instead of writing it directly to disk (which you seem to be attempting to do).
The only thing I can think of that's eating up memory here is the outputbuffer. It may not be flushing automatically, causing the JVM to attempt to map the entire output into RAM instead of writing it directly to disk (which you seem to be attempting to do).
42 Private messages asking for help will be ignored
In the frozen land of Nador they were forced to eat Steve's iMinstrels, and there was much rejoicing.
In the frozen land of Nador they were forced to eat Steve's iMinstrels, and there was much rejoicing.
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Join Date: May 2005
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Junior Poster in Training
Maybe you should try setting the maximum heap size for the JVM.
You can put higher values if needed.
For more help, www.NeedProgrammingHelp.com
java -Xmx256m MyClass
For more help, www.NeedProgrammingHelp.com
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Join Date: Nov 2004
Location: Netherlands
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doesn't matter, having a 256MB heap won't help you contain a 600MB file in memory 
You don't NEED to retain all that data in memory so the real solution is to not retain the data at all.
You don't NEED to retain all that data in memory so the real solution is to not retain the data at all.
42 Private messages asking for help will be ignored
In the frozen land of Nador they were forced to eat Steve's iMinstrels, and there was much rejoicing.
In the frozen land of Nador they were forced to eat Steve's iMinstrels, and there was much rejoicing.
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Join Date: Jun 2004
Posts: 604
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Practically a Master Poster
Hi everyone,
Is this what you meant NPH
Unfortunately i can't use the above code because the thing is the application is in a jar file on windows platform and users that use this application to run it usually double click on the jar file to run it. Is there a way to do what you suggested programatically maybe by the use of properties?
I think maybe jwenting maybe right that i have to flush and i will be trying it out.
On another question do any of you guys know how to increase the heap size programatically?
Richard West
Is this what you meant NPH
java -Xmx650m MyProgram
Unfortunately i can't use the above code because the thing is the application is in a jar file on windows platform and users that use this application to run it usually double click on the jar file to run it. Is there a way to do what you suggested programatically maybe by the use of properties?
I think maybe jwenting maybe right that i have to flush and i will be trying it out.
On another question do any of you guys know how to increase the heap size programatically?
Richard West
Microsoft uses "One World, One Web, One Program" as a slogan.
Doesn’t that sound like "Ein Volk, Ein Reich, Ein Führer" to you, too?
— Eric S. Raymond
Tell me what type of software do you like and what would you pay for it
http://www.daniweb.com/techtalkforums/thread19660.html
Doesn’t that sound like "Ein Volk, Ein Reich, Ein Führer" to you, too?
— Eric S. Raymond
Tell me what type of software do you like and what would you pay for it
http://www.daniweb.com/techtalkforums/thread19660.html
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