我正在嘗試編寫一個每天運行的

Java程序(使用任務調度程序),并且每次運行時都會在Excel電子表格中附加一列.我遇到的問題是它只是重寫文件,而不是附加到它.我正在使用Apache POI,這里是相關代碼：

public static void toExcel(List results,List notActive)throws IOException{

try {

FileInputStream fIPS= new FileInputStream("test.xls"); //Read the spreadsheet that needs to be updated

HSSFWorkbook wb;

HSSFSheet worksheet;

if(fIPS.available()>=512) {

wb = new HSSFWorkbook(fIPS); //If there is already data in a workbook

worksheet = wb.getSheetAt(0);

}else{

wb = new HSSFWorkbook(); //if the workbook was just created

worksheet = wb.createSheet("Data");

}

//Access the worksheet,so that we can update / modify it

HSSFRow row1 = worksheet.createRow(0); //0 = row number

int i=0;

Cell c = row1.getCell(i);

while (!(c == null || c.getCellType() == Cell.CELL_TYPE_BLANK)) { //cell is empty

i++;

c=row1.getCell(i);

}

HSSFRow rowx;

int x=0;

for(String s : results) {

rowx = worksheet.createRow(x);

HSSFCell cellx = rowx.createCell(i); //0 = column number

cellx.setCellValue(s);

x++;

}

fIPS.close(); //Close the InputStream

FileOutputStream output_file =new FileOutputStream("test.xls");//Open FileOutputStream to write updates

wb.write(output_file); //write changes

output_file.close(); //close the stream

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

}

我認為你是一次又一次地創建新的行和單元格并導致重寫excel.

Essentially you need to get the rows and cells instead of creating

them in your program.

HSSFRow row1 = worksheet.createRow(0);

您可能需要獲取行而不是創建它.

HSSFRow row1 = worksheet.getRow(0);

這個小例子更新了第二行的第二個單元格：

//Read the spreadsheet that needs to be updated

FileInputStream fsIP= new FileInputStream(new File("C:\\Excel.xls"));

//Access the workbook

HSSFWorkbook wb = new HSSFWorkbook(fsIP);

//Access the worksheet,so that we can update / modify it.

HSSFSheet worksheet = wb.getSheetAt(0);

// declare a Cell object

Cell cell = null;

// Access the second cell in second row to update the value

cell = worksheet.getRow(1).getCell(1);

// Get current cell value value and overwrite the value

cell.setCellValue("OverRide existing value");

//Close the InputStream

fsIP.close();

//Open FileOutputStream to write updates

FileOutputStream output_file =new FileOutputStream(new File("C:\\Excel.xls"));

//write changes

wb.write(output_file);

//close the stream

output_file.close();

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