title: Heap error while writing xls file with Apache POI
body: <p>I am using Apache POI to create an excel[.xls] file. Now an excel can have 65535 rows &amp; 256 cols. I am trying to write the java code to write the xls file with 65535x256 cells. I am getting a heap error. The current heap conf is -Xms512m -Xmx1700m.
  RAM size is 3.5gb.</p>
  
  <p>What is the way out for me ?
  I am using HSSF* classes to write xls file.</p>
  
  <p>Stack Trace is (I have enabled the -verbose:gc option)</p>
  
  <pre><code>[Full GC [Tenured: 1092288K-&gt;1092288K(1092288K), 3.3174494 secs] 1583807K-&gt;1583807K(1583808K), [Perm : 3351K-&gt;3351K(12288K)], 3.3174977 secs] [Times: user=3.30 sys=0.03, real=3.33 secs] 
  [Full GC [Tenured: 1092288K-&gt;1092288K(1092288K), 3.3073908 secs] 1583807K-&gt;1583807K(1583808K), [Perm : 3351K-&gt;3351K(12288K)], 3.3074374 secs] [Times: user=3.30 sys=0.01, real=3.31 secs] 
  [Full GC [Tenured: 1092288K-&gt;9438K(1092288K), 0.3264828 secs] 1583807K-&gt;9438K(1583808K), [Perm : 3351K-&gt;3351K(12288K)], 0.3265362 secs] [Times: user=0.31 sys=0.00, real=0.31 secs] 
  Exception in thread "main" Heap
   def new generation   total 491520K, used 44939K [0x02990000, 0x23ee0000, 0x23ee0000)
    eden space 436928K,  10% used [0x02990000, 0x05572fa8, 0x1d440000)
    from space 54592K,   0% used [0x1d440000, 0x1d440000, 0x20990000)
    to   space 54592K,   0% used [0x20990000, 0x20990000, 0x23ee0000)
   tenured generation   total 1092288K, used 9438K [0x23ee0000, 0x66990000, 0x66990000)
     the space 1092288K,   0% used [0x23ee0000, 0x24817810, 0x24817a00, 0x66990000)
   compacting perm gen  total 12288K, used 3357K [0x66990000, 0x67590000, 0x6a990000)
     the space 12288K,  27% used [0x66990000, 0x66cd7778, 0x66cd7800, 0x67590000)
  No shared spaces configured.
  java.lang.OutOfMemoryError: Java heap space
      at org.apache.poi.hssf.usermodel.HSSFRow.createCell(HSSFRow.java:147)
      at org.apache.poi.hssf.usermodel.HSSFRow.createCell(HSSFRow.java:125)
      at org.apache.poi.hssf.usermodel.HSSFRow.createCell(HSSFRow.java:103)
      at com.test.ExcelWriter.createWorkbook(ExcelWriter.java:119)
      at com.test.TestMe2.main(TestMe2.java:38)
  </code></pre>