我正在使用 apache POI 创建一个包含多个电子表格的 excel 文件。首先,此方法应在检查其存在后检查工作簿是否为空。如果为空,则创建新的工作表名称“sheet1”;如果不是,请检查此工作簿中名为“sheet1”的所有工作表。如果是,则向工作表添加新行;如果不是,则创建工作表名称“sheet1”。以下是我当前的代码,我认为这不是实现我的目标的正确方法:
File file = new File("Main Data.xlsx");
// Retrieve the workbook for the main report
XSSFWorkbook workbook;
// Check file existence
if (file.exists() == false) {
// Create new file if it does not exist
workbook = new XSSFWorkbook();
} else {
try (
// Make current input to exist file
InputStream is = new FileInputStream(file)) {
workbook = new XSSFWorkbook(is);
}
}
XSSFSheet spreadsheet;
// Check if the workbook is empty or not
if (workbook.getNumberOfSheets() != 0) {
for (int i = 0; i < workbook.getNumberOfSheets(); i++) {
if (workbook.getSheetName(i).equals(" Enc " + deviceLabel.getText() + " Info. ")) {
spreadsheet = workbook.getSheet(" Enc " + deviceLabel.getText() + " Info. ");
} else spreadsheet = workbook.createSheet(" Enc " + deviceLabel.getText() + " Info. ");
}
}
else {
// Create new sheet to the workbook if empty
spreadsheet = workbook.createSheet(" Enc " + deviceLabel.getText() + " Info. ");
}
// Error here (variable spreadsheet may not have been initialized
spreadsheet.shiftRows(0, spreadsheet.getLastRowNum(), 23);
我遇到了两个问题。
- for 循环对于实现我的目标显然是错误的。有什么方法可以在一个 if 语句中同时检查空电子表格或命名电子表格是否已经存在?
例如
if ((workbook.getNumberOfSheets() == 0) && !workbook.getSheet("sheet1").exists()) {
workbook.createSheet("sheet1");
} else workbook.getSheet("sheet1")
- 我一直收到电子表格未初始化的错误,但如果我删除 for 循环,错误就会消失。
最佳答案
我用下面的代码想出了我的问题:
File file = new File("Main Data.xlsx");
// Retrieve the workbook for the main report
XSSFWorkbook workbook;
// Check file existence
if (file.exists() == false) {
// Create new file if it does not exist
workbook = new XSSFWorkbook();
} else {
try (
// Make current input to exist file
InputStream is = new FileInputStream(file)) {
workbook = new XSSFWorkbook(is);
}
}
XSSFSheet spreadsheet = workbook.getSheet("sheet1");
// Check if the workbook is empty or not
if (workbook.getNumberOfSheets() != 0) {
for (int i = 0; i < workbook.getNumberOfSheets(); i++) {
if (workbook.getSheetName(i).equals("sheet1")) {
spreadsheet = workbook.getSheet("sheet1");
} else spreadsheet = workbook.createSheet("sheet1");
}
}
else {
// Create new sheet to the workbook if empty
spreadsheet = workbook.createSheet("sheet1");
}
// Shift rows down if exist
spreadsheet.shiftRows(0, spreadsheet.getLastRowNum(), 23);
关于Java Check 工作簿包含特定电子表格或不使用 Apache POI,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43645607/