This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Hello everyone. I am creating a JavaServlet which reads a file (using a BufferedReader). Now, when I've read this file, I want to process it (search for a Stringpattern.) This is not really the problem. The problem is that the reading of the file (around 50MB) takes a very long time (on slow machines, around 15 seconds..). Therefore I want to read it only once (e.g. in init() ), and put it in memory (application scope) after that. Now I tried using the readLine() methode to put the file in a Hashtable, or in a Vector, but both fail because of an 'Out of Memory' error. When I use a small file, there's no problem, and everything works extremely fast. Usually the error occurs after processing 68000 lines of text...that's not even halfway the actual file. Does anyone got an idea on how to solve this problem? Any help would be greatly appriciated! Thanks, Erik
You could try bumping up the amount of memory that the JVM has access to using the -mx mem and -ms mem parameters when starting the JVM. >java -ms32mb MyApplication From the Sun Tools Documentation
-mxx Sets the maximum size of the memory allocation pool (the garbage collected heap) to x. The default is 16 megabytes of memory. x must be greater than or equal to 1000 bytes. By default, x is measured in bytes. You can specify x in either kilobytes or megabytes by appending the letter "k" for kilobytes or the letter "m" for megabytes. -ms x Sets the startup size of the memory allocation pool (the garbage collected heap) to x. The default is 1 megabyte of memory. x must be > 1000 bytes. By default, x is measured in bytes. You can specify x in either kilobytes or megabytes by appending the letter "k" for kilobytes or the letter "m" for megabytes.
"JavaRanch, where the deer and the Certified play" - David O'Meara
Joined: Sep 08, 2001
Thanks for your advice, but I don't think this is very usefull to my, because I don't know the size of the memory, and the size of the files can also change. I was just hoping there would be some other way to process this file quickly (within 1 second). Thanks anyway! Erik