如何使用POI将巨大的.csv文件转换为excel

我有Java代码将CSV转换为xlsx。 它工作正常与一个小文件大小。 现在我有一个CSV文件与20万logging（200,000），并在转换我得到一个内存不足的错误。

我尝试将工作簿更改为SXSSFWorkbook，并将堆大小和Java内存大小增加到-Xms8G -Xmx10G。 即使这样也行不通。 我在一个UNIX盒子上试了一下。

在search时，我得到了一些关于使用BigGridDemo的代码。 任何人都可以帮助我自定义读取.csv文件，然后使用其逻辑写入xlsx或任何其他解决scheme？

try { FileReader input = new FileReader(strFileToConvert); BufferedReader bufIn = new BufferedReader(input); if(strExcel_Typ.equals("-xls")) { wbAll = new HSSFWorkbook(); } else { wbAll = new SXSSFWorkbook(100); wbAll.setCompressTempFiles(true); } sheetAll = wbAll.createSheet(); rowAll = null; cellAll = null; shoRowNumAll = 0; // do buffered reading from a file while ((line = bufIn.readLine()) != null) { intCntr++; //if there is any data in the line if (line.length() > 0) { System.out.println(shoRowNumAll); //create a new row on the spreadsheet rowAll = sheetAll.createRow((int)shoRowNumAll); shoRowNumAll++; if (line.indexOf("\"", 0) > 0) { if (intCntr == 1) { //only issue the message the first time quotes are found System.out.println("Double quotes found. Stripping double quotes from file"); } line = line.replaceAll("\"", ""); } //if its the first row and no delimiters found, there is a problem if (line.indexOf(strDelim, 0) == -1 && intCntr == 1) { System.exit(1); } processLine(line); ((SXSSFSheet) sheetAll).flushRows(100); } } bufIn.close(); /write the excel file try { String file = strOutPutFile; ExcelOutAll = new FileOutputStream(file); wbAll.write(ExcelOutAll); } catch (IOException e) { System.err.println(e.toString()); } ExcelOutAll.close(); 

stream程线方法：

 processLine(String line) { //find the first next delimiter starting in position 0 intNxtComma = line.indexOf(strDelim, 0); while (intCurPosInLine < line.trim().replaceAll(",","").length()) { strCellContent = line.substring((intCurPosInLine), intNxtComma); //create a new cell on the new row cellAll = rowAll.createCell(intCellNum); //set the font defaults Font font_couriernew_10 = wbAll.createFont(); font_couriernew_10.setFontHeightInPoints((short)10); font_couriernew_10.setFontName("Courier New"); CellStyle cellStyle = wbAll.createCellStyle(); //if its the first row, center the text if (shoRowNumAll == 1) { cellStyle.setAlignment(CellStyle.ALIGN_CENTER); font_couriernew_10.setBoldweight(XSSFFont.BOLDWEIGHT_BOLD); } cellStyle.setFont(font_couriernew_10); // if the col. needs to be numeric, set the cell format to number if ((strNumericCols.indexOf(Integer.toString(intCellNum), 0) > -1) && (intCntr > 1)) { DataFormat datafrmt = wbAll.createDataFormat(); cellStyle.setDataFormat(datafrmt.getFormat("$#,##0.00")); } cellAll.setCellStyle(cellStyle); //populate the cell if ((strNumericCols.indexOf(Integer.toString(intCellNum), 0) > -1) && (intCntr > 1)) { //if the col. needs to be numeric populate with a number if(strCellContent != null && !"".equals(strCellContent.trim())){ douCellContent = Double.parseDouble(strCellContent.replaceAll(",","")); cellAll.setCellValue(douCellContent); } } else { cellAll.setCellValue(strCellContent.trim()); } intCellNum++; intCurPosInLine = intNxtComma + 1; //if we dont find anymore delimiters, set the variable to the line length if (line.indexOf(strDelim, intCurPosInLine) == -1) { intNxtComma = line.trim().length(); } else { intNxtComma = line.indexOf(strDelim, intNxtComma + 1); } } }