编辑:我使用这个代码来读取excel表的行和列。但是用双星标记的行抛出异常(java.lang.)。nullpointer例外)。除此之外,我还想将中间的空列转换为空列。请帮助。
有两个循环,一个用于行,一个用于列,这很明显。既没有读取行,也没有解决空白单元格问题。
public void read(String filePath) throws NullPointerException {
try {
FileInputStream file = new FileInputStream(new File(filePath));
System.out.println("going to create Workbook object to read excel row wise");// Create Workbook instance holding reference to .xlsx file
XSSFWorkbook workbook = new XSSFWorkbook(file);
System.out.println("going to create object sheet to read excel row wise");
XSSFSheet sheet = workbook.getSheetAt(0); //extracts the first sheet of excel
System.out.println("Running row iterator to read excel row wise");
for (int rowNumber = sheet.getFirstRowNum(); rowNumber <= sheet.getLastRowNum(); rowNumber++) {
if (rowNumber == sheet.getFirstRowNum())// this row was skipped as it was header row.
{
System.out.println("skipping first row");
continue;
}
this.rowconcat = ""; // all values of perticular row will be concatinated in this variable.
this.flag = 0;
if (sheet.getRow(rowNumber) == null) {
System.out.println("row detected null");
} else {
// The row has data
System.out.println("row no inside else==="+rowNumber);
**Row row = sheet.getRow(rowNumber);** //This line here throws null pointer exception.
for (int cellNumber = row.getFirstCellNum(); cellNumber <= row.getLastCellNum(); cellNumber++) {
Cell cell = row.getCell(cellNumber);
if (cell == null || cell.getCellType() == Cell.CELL_TYPE_BLANK) {
this.flag = 1; // set to 1 to indicate blank cell but this also doesn't work
cell.setCellType(Cell.CELL_TYPE_STRING);
cell.setCellValue(" "); //inserting space in cell after converting its type to String.
this.rowconcat = this.rowconcat + cell.getStringCellValue() + "~";
} else {
cell.setCellType(Cell.CELL_TYPE_STRING);
this.rowconcat = this.rowconcat + cell.getStringCellValue() + "~";
}
}
}
}
}//try block closure
catch(Exception e){
//autogenerated
}
} // function closure
我推荐JXL库比apache1更好,我已经使用它很长时间了。它唯一的小问题是它只适用于xls而不是xlsx(如果到现在还没有更新的话!)。
有一个小的例子:
File xlsFile;
public void manageData ()
{
Workbook w;
try {
w = Workbook.getWorkbook(xlsFile);
// Get the first sheet
Sheet sheet = w.getSheet(0);
int j = 1;
//Begin from the second row
while (j < sheet.getColumns()) {
//staff
Cell infoCell = sheet.getCell(j, 4);
System.out.println(infoCell.getContents());
}
catch (Exception e)
{
}
}