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我得到heap space错误，同时从数据库中写入大量数据的Excel工作表。 我不想使用JVM -XMX选项来增加内存。Java堆空间错误，OutOfMemory例外而写大数据的Excel工作表
以下是详细信息：
1）我使用org.apache.poi.hssf API 的Excel工作表的写作。
2）JDK 1.5版
3）的Tomcat 6.0
代码，我wriiten作品以及周边的23000条记录，但它不能超过23K的记录。
以下是代码：
ArrayList l_objAllTBMList= new ArrayList();
l_objAllTBMList = (ArrayList) m_objFreqCvrgDAO.fetchAllTBMUsers(p_strUserTerritoryId);
ArrayList l_objDocList = new ArrayList();
m_objTotalDocDtlsInDVL= new HashMap();
Object l_objTBMRecord[] = null;
Object l_objVstdDocRecord[] = null;
int l_intDocLstSize=0;
VisitedDoctorsVO l_objVisitedDoctorsVO=null;
int l_tbmListSize=l_objAllTBMList.size();
System.out.println(" getMissedDocDtlsList_NSM ");
for(int i=0; i<l_tbmListSize;i++)
{
l_objTBMRecord = (Object[]) l_objAllTBMList.get(i);
l_objDocList = (ArrayList) m_objGenerateVisitdDocsReportDAO.fetchAllDocDtlsInDVL_NSM((String) l_objTBMRecord[1], p_divCode, (String) l_objTBMRecord[2], p_startDt, p_endDt, p_planType, p_LMSValue, p_CycleId, p_finYrId);
l_intDocLstSize=l_objDocList.size();
try {
l_objVOFactoryForDoctors = new VOFactory(l_intDocLstSize, VisitedDoctorsVO.class);
/* Factory class written to create and maintain limited no of Value Objects (VOs)*/
} catch (ClassNotFoundException ex) {
m_objLogger.debug("DEBUG:getMissedDocDtlsList_NSM :Exception:"+ex);
} catch (InstantiationException ex) {
m_objLogger.debug("DEBUG:getMissedDocDtlsList_NSM :Exception:"+ex);
} catch (IllegalAccessException ex) {
m_objLogger.debug("DEBUG:getMissedDocDtlsList_NSM :Exception:"+ex);
}
for(int j=0; j<l_intDocLstSize;j++)
{
l_objVstdDocRecord = (Object[]) l_objDocList.get(j);
l_objVisitedDoctorsVO = (VisitedDoctorsVO) l_objVOFactoryForDoctors.getVo();
if (((String) l_objVstdDocRecord[6]).equalsIgnoreCase("-"))
{
if (String.valueOf(l_objVstdDocRecord[2]) != "null")
{
l_objVisitedDoctorsVO.setPotential_score(String.valueOf(l_objVstdDocRecord[2]));
l_objVisitedDoctorsVO.setEmpcode((String) l_objTBMRecord[1]);
l_objVisitedDoctorsVO.setEmpname((String) l_objTBMRecord[0]);
l_objVisitedDoctorsVO.setDoctorid((String) l_objVstdDocRecord[1]);
l_objVisitedDoctorsVO.setDr_name((String) l_objVstdDocRecord[4] + " " + (String) l_objVstdDocRecord[5]);
l_objVisitedDoctorsVO.setDoctor_potential((String) l_objVstdDocRecord[3]);
l_objVisitedDoctorsVO.setSpeciality((String) l_objVstdDocRecord[7]);
l_objVisitedDoctorsVO.setActualpractice((String) l_objVstdDocRecord[8]);
l_objVisitedDoctorsVO.setLastmet("-");
l_objVisitedDoctorsVO.setPreviousmet("-");
m_objTotalDocDtlsInDVL.put((String) l_objVstdDocRecord[1], l_objVisitedDoctorsVO);
}
}
}// End of While
writeExcelSheet(); // Pasting this method at the end
// Clean up code
l_objVOFactoryForDoctors.resetFactory();
m_objTotalDocDtlsInDVL.clear();// Clear the used map
l_objDocList=null;
l_objTBMRecord=null;
l_objVstdDocRecord=null;
}// End of While
l_objAllTBMList=null;
m_objTotalDocDtlsInDVL=null;
-------------------------------------------------------------------
private void writeExcelSheet() throws IOException
{
HSSFRow l_objRow = null;
HSSFCell l_objCell = null;
VisitedDoctorsVO l_objVisitedDoctorsVO = null;
Iterator l_itrDocMap = m_objTotalDocDtlsInDVL.keySet().iterator();
while (l_itrDocMap.hasNext())
{
Object key = l_itrDocMap.next();
l_objVisitedDoctorsVO = (VisitedDoctorsVO) m_objTotalDocDtlsInDVL.get(key);
l_objRow = m_objSheet.createRow(m_iRowCount++);
l_objCell = l_objRow.createCell(0);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(String.valueOf(l_intSrNo++));
l_objCell = l_objRow.createCell(1);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getEmpname() + " (" + l_objVisitedDoctorsVO.getEmpcode() + ")"); // TBM Name
l_objCell = l_objRow.createCell(2);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getDr_name());// Doc Name
l_objCell = l_objRow.createCell(3);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getPotential_score());// Freq potential score
l_objCell = l_objRow.createCell(4);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getDoctor_potential());// Freq potential score
l_objCell = l_objRow.createCell(5);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getSpeciality());//CP_GP_SPL
l_objCell = l_objRow.createCell(6);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getActualpractice());// Actual practise
l_objCell = l_objRow.createCell(7);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getPreviousmet());// Lastmet
l_objCell = l_objRow.createCell(8);
l_objCell.setCellStyle(m_objCellStyle4);
l_objCell.setCellValue(l_objVisitedDoctorsVO.getLastmet());// Previousmet
}
// Write OutPut Stream
try {
out = new FileOutputStream(m_objFile);
outBf = new BufferedOutputStream(out);
m_objWorkBook.write(outBf);
} catch (Exception ioe) {
ioe.printStackTrace();
System.out.println(" Exception in chunk write");
} finally {
if (outBf != null) {
outBf.flush();
outBf.close();
out.close();
l_objRow=null;
l_objCell=null;
}
}
}
我已经搜索了堆空间错误很多人建议使用-Xmx选项增加JVM memoery。但是我有一些限制，所以不能以这种方式使用。 – PrashantK 2011-03-24 07:18:48
@Suresh S如果超过23K不能工作，25K批次将不起作用。 – Thomas 2011-03-24 07:25:50
@Prashank：好的，然后像每批20k一样做。 – 2011-03-24 07:31:50