Iz Jave želim prebrati in zapisati datoteko Excel s 3 stolpci in N vrsticami ter v vsako celico natisniti en niz. Ali mi lahko kdo ponudi preprost delček kode za to? Ali moram uporabiti kakšen zunanji lib ali ima Java vgrajeno podporo za to?
Želim narediti naslednje:
for(i=0; i <rows; i++)
//read [i,col1] ,[i,col2], [i,col3]
for(i=0; i<rows; i++)
//write [i,col1], [i,col2], [i,col3]
Poskusite s Apache POI HSSF. Tukaj je primer, kako prebrati datoteko Excel:
try {
POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(file));
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row;
HSSFCell cell;
int rows; // No of rows
rows = sheet.getPhysicalNumberOfRows();
int cols = 0; // No of columns
int tmp = 0;
// This trick ensures that we get the data properly even if it doesn't start from first few rows
for(int i = 0; i < 10 || i < rows; i++) {
row = sheet.getRow(i);
if(row != null) {
tmp = sheet.getRow(i).getPhysicalNumberOfCells();
if(tmp > cols) cols = tmp;
}
}
for(int r = 0; r < rows; r++) {
row = sheet.getRow(r);
if(row != null) {
for(int c = 0; c < cols; c++) {
cell = row.getCell((short)c);
if(cell != null) {
// Your code here
}
}
}
}
} catch(Exception ioe) {
ioe.printStackTrace();
}
Na strani z dokumentacijo imate tudi primere, kako pisati v datoteke excel.
Apache POI lahko to stori namesto vas. Zlasti modul HSSF. Najbolj uporaben je hitri vodnik. Tukaj je opisano, kako narediti, kar želite - ustvarite list in ga napišite.
Workbook wb = new HSSFWorkbook();
//Workbook wb = new XSSFWorkbook();
CreationHelper createHelper = wb.getCreationHelper();
Sheet sheet = wb.createSheet("new sheet");
// Create a row and put some cells in it. Rows are 0 based.
Row row = sheet.createRow((short)0);
// Create a cell and put a value in it.
Cell cell = row.createCell(0);
cell.setCellValue(1);
// Or do it on one line.
row.createCell(1).setCellValue(1.2);
row.createCell(2).setCellValue(
createHelper.createRichTextString("This is a string"));
row.createCell(3).setCellValue(true);
// Write the output to a file
FileOutputStream fileOut = new FileOutputStream("workbook.xls");
wb.write(fileOut);
fileOut.close();