Import data from excel/csv file in web dynpro

Question

Hi All,
I need to populate a WD table by first importing a excel/CSV file thru web dynpro screen and then reading thru the file.Am using FileUpload element from NW04s.
How can I read/import data from excel / csv file in web dynpro table context?
Any help is appreciated.
Thanks a lot
Aakash

Answer 1

Hi,
Here are the basic steps needed to read data from excel spreadsheet using the Java Excel API(jExcel API).
jExcel API can read a spreadsheet from a file stored on the local file system or from some input stream, ideally the following should be the steps while reading:
Create a workbook from a file on the local file system, as illustrated in the following code fragment:
          import java.io.File;
          import java.util.Date;
          import jxl.*;
         Workbook workbook = Workbook.getWorkbook(new File("test.xls"));
On getting access to the worksheet, once can use the following code piece to access  individual sheets. These are zero indexed - the first sheet being 0, the  second sheet being 1, and so on. (You can also use the API to retrieve a sheet by name).
          Sheet sheet = workbook.getSheet(0);
After getting the sheet, you can retrieve the cell's contents as a string by using the convenience method getContents(). In the example code below, A1 is a text cell, B2 is numerical value and C2 is a date. The contents of these cells may be accessed as follows
Cell a1 = sheet.getCell(0,0);
Cell b2 = sheet.getCell(1,1);
Cell c2 = sheet.getCell(2,1);
String a1 = a1.getContents();
String b2 = b2.getContents();
String c2 = c2.getContents();
// perform operations on strings
However in case we need to access the cell's contents as the exact data type ie. as a numerical value or as a date, then the retrieved Cell must be cast to the correct type and the appropriate methods called. The code piece given below illustrates how JExcelApi may be used to retrieve a genuine java double and java.util.Date object from an Excel spreadsheet. For completeness the label is also cast to it's correct type. The code snippet also illustrates how to verify that cell is of the expected type - this can be useful when performing validations on the spreadsheet for presence of correct datatypes in the spreadsheet.
  String a1 = null;
  Double b2 = 0;
  Date c2 = null;
                    Cell a1 = sheet.getCell(0,0);
                    Cell b2 = sheet.getCell(1,1);
                    Cell c2 = sheet.getCell(2,1);
                    if (a1.getType() == CellType.LABEL)
                       LabelCell lc = (LabelCell) a1;
                       stringa1 = lc.getString();
                     if (b2.getType() == CellType.NUMBER)
                       NumberCell nc = (NumberCell) b2;
                       numberb2 = nc.getValue();
                      if (c2.getType() == CellType.DATE)
                        DateCell dc = (DateCell) c2;
                        datec2 = dc.getDate();
                       // operate on dates and doubles
It is recommended to, use the close()  method (as in the code piece below)   when you are done with processing all the cells.This frees up any allocated memory used when reading spreadsheets and is particularly important when reading large spreadsheets.              
          // Finished - close the workbook and free up memory
          workbook.close();
The API class files are availble in the 'jxl.jar', which is available for download.
Regards
Raghu