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Thread: Program eating a lot of memory

  1. #1
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    Default Program eating a lot of memory

    Hello, i have a simple program that seems to take a lot of memory, about 700MB. As the program starts it keeps growing slowly until it reaches 700-1000MB and then it doesn't grow anymore. What my program does is open a webpage and analize its data, extract certain strings from its text and store it in a file. It stores each string in a separate line and the biggest of those files is about 4MB. I temporary store this strings in a set, manipulate it, compare it with others, read them from files and write them to files. The whole code is to big to share so i will just post some important things from it and hopefuly u will figure out where the problem is. Alternatively if there is a way for me to monitor which function or part of program is taking all this space, that would be ok too.

    This is how i read Strings from a file

    // fill positives	
    		Set<String> positives = new HashSet<String>();
     
    		try {
    			Scanner scanner = new Scanner(new File("positives.txt"));
    			while (scanner.hasNextLine()) {
     
    				String line = scanner.nextLine();														
    				positives.add(line); 
     
    			} 					
     
    			scanner.close();
    		} catch (FileNotFoundException e) {
    			e.printStackTrace();
    		}


    This is how i write Strings from a Set to file
    // write positives to file		
    		f1 = new FileWriter("positives.txt");
    		newLine = System.getProperty("line.separator");	
     
    		for (String s : positives) {
    			f1.write(s + newLine);
    		}
     
    		f1.close();


    This is how i remove files from set that are in the other set. Keep in mind that there is never more then 4MB of Strings in any of this set
    // remove from candidates all processed
     
    		candidates.removeAll(checkedTemp);

    This is how i get strings from a site.
    public static void readPage(String url, int pageNumber) {
     
     
     
    		String temp;
     
    		try {			
    			URL oracle;
    			oracle = new URL(url + String.valueOf(pageNumber));			
    			BufferedReader in = new BufferedReader(
    			new InputStreamReader(oracle.openStream()));
     
    			String inputLine;
    			int line= 0;
     
    			while ((inputLine = in.readLine()) != null) {
     
     
    					temp = extractStrings(inputLine);	
     
    					if(temp != null) {		
    						candidates.add(temp);											
    						candidatesCounter++;			
    					} 
    					line++;
     
     
    				}		
    					in.close();				
    			} catch(Exception e) {
    				System.out.print("error: ");
    				System.out.println(e);		
    			}	
     
     
     
     
     
     
    	}

    This is how i process the webpage. It ready about 40 pages full of text and uses StringUtils library to find strings that are in a certain place (and example would be, find all strings that start with /ri and end with .jpg)
    public static String extractStrings(String line) {				
     
    		String result = StringUtils.substringBetween(line, "ri/", ".jpg");
    		if(result != null) return result;
     
    		return null;     
     
    	}

  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Program eating a lot of memory

    There are some monitoring programs that will help you find where the code is executing and perhaps where memory is being used. I don't know the names of any of them.
    If you don't understand my answer, don't ignore it, ask a question.

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