Hi Mohan, Are you cleaning up unwanted objects?
The JVM will simply expand, surprising quickly, if you do not 'Destroy' objects you no longer need. Regards, Mark. ________________________________ From: Mohan Nuggehally <[email protected]> To: [email protected] Sent: Monday, 27 October 2014, 19:14 Subject: out of memory and GC overhead limit error I get this error when I try to create an excel sheet using xssf. All I am doing is creating rows and columns by reading contents from a file. Of course when I change the max heap size from 1GB to 6GB it works. I wonder if 1GB is really too small or is the code bad and therefore requires a huge heap. Any experiences ? Here is the error stack. ------------- Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at org.apache.poi.ss.util.CellReference.convertNumToColString(CellReference.java:433) at org.apache.poi.ss.util.CellReference.appendCellReference(CellReference.java:492) at org.apache.poi.ss.util.CellReference.formatAsString(CellReference.java:455) at org.apache.poi.xssf.usermodel.XSSFCell.setCellNum(XSSFCell.java:710) at org.apache.poi.xssf.usermodel.XSSFRow.createCell(XSSFRow.java:175) at org.apache.poi.xssf.usermodel.XSSFRow.createCell(XSSFRow.java:147) at org.apache.poi.xssf.usermodel.XSSFRow.createCell(XSSFRow.java:39) at GraphWriteFull_to_Excel.create_sheet(GraphWriteFull_to_Excel.java:150) at GraphWriteFull_to_Excel.main(GraphWriteFull_to_Excel.java:79) ---------------- The error stack is different as below when I set the max heap size to 4GB -------------- Exception in thread "main" java.lang.OutOfMemoryError: GC overhead limit exceeded at java.util.Arrays.copyOfRange(Arrays.java:2694) at java.lang.String.<init>(String.java:203) at java.lang.String.copyValueOf(String.java:2908) at java.io.StreamTokenizer.nextToken(StreamTokenizer.java:702) at GraphWriteFull_to_Excel.create_sheet(GraphWriteFull_to_Excel.java:151) at GraphWriteFull_to_Excel.main(GraphWriteFull_to_Excel.java:79) --------------- I appreciate any feedback. Regards, -Mohan -- Mohan Nuggehally Senior Developer, Es-ice Office: Direct dial: 1-631-760-3244 Internal extension: 25172 New York
