Working with Big Excel Sheet

Question

Hello All,
I have a large excel sheet having 50K rows and I am constrained to not use more than 250 MB of Heap space.
Using Apache poi API the creating new WorkBook Object itself gives MemoryOutOfSpace Error
Workbook source = WorkbookFactory.create(new FileInputStream(Path));
Please suggest some solution/work around. I am open to use some other API as well but preference lies for Apache poi.
Thanks In Anticipation
Shivam

Answer 1

This is the sample code that I am running, I am only creating an Workbook object and then traversing the excel. I am getting the java.lang.OutOfMemoryError: Java heap space error
package excel;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;
public class BigFile {
     private static String DATE_FORMAT = "yyyy_MM_dd_HH_mm_ss";
     public static String calcTimeStamp()
          Date date = new Date();
          SimpleDateFormat format = new SimpleDateFormat(DATE_FORMAT);
          return format.format(date.getTime());
     public static void main(String args[])
          String Path = "C:\\EXCEL\\Large.xls";
          long t = System.currentTimeMillis();
          try {
               Workbook source = WorkbookFactory.create(new FileInputStream(Path));
               Sheet sheet = source.getSheetAt(0);
               for (Row row : sheet)
                    for (Cell cell : row)
          }catch (FileNotFoundException e) {
               e.printStackTrace();
          } catch (IOException e) {
               e.printStackTrace();
          }catch (Exception e)
               e.printStackTrace();
          }finally {
               System.out.println("Total Time Taken "
                         + (System.currentTimeMillis() - t)/1000 + " seconds");
               System.out.println("End Time :" + calcTimeStamp()+" in "+System.getProperty("user.timezone")+" timezone");
Here is the Stack Trace
Total Time Taken 10 seconds
End Time :2011_03_31_09_40_26 in Asia/Calcutta timezone
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
     at java.util.Arrays.copyOf(Unknown Source)
     at java.util.Arrays.copyOf(Unknown Source)
     at java.util.ArrayList.ensureCapacity(Unknown Source)
     at java.util.ArrayList.add(Unknown Source)
     at org.apache.poi.hssf.record.RecordFactory.createRecords(RecordFactory.java:443)
     at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:263)
     at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:188)
     at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:305)
     at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:286)
     at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:60)
     at excel.BigFile.main(BigFile.java:33)