How to clear contents of a column in excel sheet using java - java

I want to clear contents of 3 columns in excel sheet(.xlsx file) using java before execution of my selenium script. i am using XSSFWorkbook(Apache poi) for read and write data to excel sheet.There are 5 columns in excel sheet.I want to clear 3 column contents and remaining column content should keep like before.
please help me how can i achieve that?

FileInputStream objFileInputStream = new FileInputStream(new File(
Xlsx_File_path.xlsx));
XSSFWorkbook objWorkbook = new XSSFWorkbook(objFileInputStream);
XSSFSheet objSheet = objWorkbook.getSheetAt(0);
Cell cell = null;
int row=[start of row]
int cell=[your cell]
//iterate the below code as you want
//code
cell = objSheet.getRow(rows).getCell(cell);
cell.setCellValue("")
//code
objFileInputStream.close();
FileOutputStream output_file = new FileOutputStream(new File(
finalXlsx.xlsx));
objWorkbook.write(output_file);
output_file.close();

Related

Not able to write data in xlsx file using java?

I Have a data stored in variables and then i want to write my data to excel file(.xlsx).
(i.e) I use automation testing tools like selenium to get data from webpage and i store it in variable which i want to wrie in xlsx file
After a lot of google search I found many of users uses list or objects to write into .xlsx file.
I created a list and add my variable to that list and using looping statements (for loop) i checked whether my data is stored in list by printing it.
Then I created XSSFWorkbook and XSSFSheet and XSSFRow and XSSFCell to write data.
I write a cell by using setCellValue method to my cell.
My code successfully creates a xlsx file and sheet in it
but after execution i could not able to find any data in it.
Source code:
ArrayList<String> head = new ArrayList<String>();
head.add("Register Number");
head.add(subject1);
head.add(subject2); //subject1 and subject2 are variable i created
System.out.println(head.get(1)); //To check if my list has value
XSSFWorkbook workbook = new XSSFWorkbook();
FileOutputStream fileOut = new FileOutputStream("/home/st.xlsx");
for (int i = 0; i < head.size(); i++)
{
XSSFRow Row = sheet1.createRow(1);
XSSFCell cell = Row.createCell(1);
cell.setCellValue(head.get(1));
sheet1.autoSizeColumn(1);
}
workbook.write(fileOut);
fileOut.close();
I expect my code add data to my file.
Main thing is During execution when i try to open my .xlsx file it has data in it.
But after the complete execution i get with the empty xlsx file.
I don't know why i'm getting this and What wrong in my code?
Thanks in advance!
ArrayList<String> head = new ArrayList<String>();
head.add("Register Number");
head.add(subject1);
head.add(subject2); // subject1 and subject2 are variable i created
System.out.println(head.get(0)); // To check if my list has value
System.out.println(head.get(1)); // To check if my list has value
System.out.println(head.get(2)); // To check if my list has value
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet sheet1 = wb.createSheet("Sheet1");
for (int r = 0; r < head.size(); r++)
{
XSSFRow row = sheet1.createRow(r);
XSSFCell cell = row.createCell(0);
cell.setCellValue(head.get(r));
sheet1.autoSizeColumn(0);
}
// Write this workbook to a FileOutputStream.
FileOutputStream fileOut = new FileOutputStream("/home/st.xlsx");
workbook.write(fileOut);
fileOut.flush();
fileOut.close();
More info here:
https://gist.github.com/madan712/3912272

Apache POI not "Saving" excel file

I am writing a small utility that creates a pivot table in an excel sheet using POI and I want to read the data from the pivot table back to the program which will save it as a PDF file using Itext. I am running into a problem where the program cannot read the data from the pivot table after it is created. The program only can "see" the information in the pivot table after I manually open the created file and hit the save button in excel. Does anyone know a way to read the data from the pivot table from the XSSFPivotTable object or otherwise force a way for the file to "save" so it can be accessed by the program again?
Here is a snippet of code so you can see what I'm talking about. I'm a student so any advice on best practices would be greatly appreciated as well.
public void returnPivotData() throws IOException {
FileInputStream fs = new FileInputStream(this.xlsxFile);
XSSFWorkbook book = new XSSFWorkbook(fs);
XSSFSheet dataSheet = book.getSheet("Sheet1");
AreaReference dataRef = new AreaReference("A1:E15",
SpreadsheetVersion.EXCEL2007);
XSSFPivotTable table = dataSheet.createPivotTable(dataRef,
new CellReference("A16"));
table.addRowLabel(0);
table.addColumnLabel(DataConsolidateFunction.SUM, 3);
// Save the data back to the file
FileOutputStream fsOut = new FileOutputStream(
"D:\\workspace\\test.xlsx");
book.write(fsOut);
fsOut.close();
book.close();
fs.close();
// This does not allow access
FileInputStream fsIn = new FileInputStream("D:\\workspace\\test.xlsx");
XSSFWorkbook bookNew = new XSSFWorkbook(fsIn);
XSSFSheet sheet = bookNew.getSheet("Sheet1");
for (int i = 0; i < 20; i++) {
XSSFRow rowNew = sheet.getRow(i);
XSSFCell cellNew = rowNew.getCell(0,
MissingCellPolicy.CREATE_NULL_AS_BLANK);
System.out.println(cellNew.toString());
}
fsIn.close();
bookNew.close();
}

Cannot read files written using SXSSFWorkbook in java

I want to read and write large excel files. Therefore, I used SXSSFWorkbook to write the excel file and XSSF and SAX EVENT API to read the files.
However, the cell content is empty when the excel file is read, and if the excel file is written using SXSSFWOrkbook. If I open the written excel file and save it again, the content is shown correctly.
The following is the code I used to write the excel file.
SXSSFWorkbook wb = new SXSSFWorkbook();
wb.setCompressTempFiles(true);
SXSSFSheet sh = (SXSSFSheet) wb.createSheet();
// sh.setRandomAccessWindowSize(100);// keep 100 rows in memory,
// exceeding rows will be flushed to disk
for (int rownum = 0; rownum < 100; rownum++) {
Row row = sh.createRow(rownum);
for (int cellnum = 0; cellnum < 10; cellnum++) {
Cell cell = row.createCell(cellnum);
String address = new CellReference(cell).formatAsString();
cell.setCellValue(address);
}
}
FileOutputStream out = new FileOutputStream("D:\\tempsxssf.xlsx");
wb.write(out);
out.flush();
out.close();
wb.dispose();
I am in a big trouble, can someone help me to figure out the issue?
I used another constructor according POI documentation
SXSSFWorkbook(workbook, rowAccessWindowSize, compressTmpFiles, useSharedStringsTable)
Like this:
SXSSFWorkbook workbook = new SXSSFWorkbook(null, 1000, true, true);
where you can enable shared strings table

Java save as dialog box to save a file at a path [duplicate]

This question already has answers here:
Simplest way to serve static data from outside the application server in a Java web application
(10 answers)
Closed 7 years ago.
I have a form that takes a PDF file and submits to servlet. After reading the content of PDF I am creating a xls file in servlet using Apache POI that I want to save to my local disc.
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("Data");
ArrayList<String> keys = new ArrayList<String>(excelData.keySet());
int counter = 0;
for(int i=keys.size()-1; i>=0;i--){
String key = keys.get(i);
String value = excelData.get(key);
Row row = sheet.createRow(counter++);
Cell cell = row.createCell(0);
cell.setCellValue(key);
Cell cell1 = row.createCell(1);
cell1.setCellValue(value);
}
//work book is the xls data that currently I am saving like ,
FileOutputStream out = new FileOutputStream(new File("C:\\Users\\user\\Desktop\\new.xls"));
workbook.write(out);
out.close();
//return back to same page.
response.sendRedirect(request.getHeader("Referer"));
Instead of saving file directly to C:\\Users\\user\\Desktop\\new.xls,I want to give a save as option to select the path and name of the file that user want to save. Some thing like :
How can I send this file back to the client browser and show save as option.
//read file back after saving to some temp path.
File pdfFile = new File("D:\\temp\\"+ fileName +".xls");
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment; filename="+fileName+".xls");
FileInputStream fileInputStream = new FileInputStream(pdfFile);
OutputStream responseOutputStream = response.getOutputStream();
int bytes;
while ((bytes = fileInputStream.read()) != -1) {
responseOutputStream.write(bytes);
}
fileInputStream.close();

Changing value of cell in Excel via apache-poi

I'm trying to change value of cell in .xls document.
In .xls file i have got only 1 cell - A1 with abc value inside.
My code:
File fo = new File("D:\\TMP\\Zeszyt1.xls");
HSSFWorkbook a = new HSSFWorkbook(new FileInputStream(fo));
HSSFSheet my_sheet = a.getSheetAt(0);
HSSFRow my_row = my_sheet.getRow(0);
HSSFCell myCell;
myCell = my_row.getCell(0);
myCell.setCellValue("NEW VALUE");
How to commit this changes? When i open .xls file i still have got abc value inside A1.
You have to write to the file.
FileOutputStream outputStream = new FileOutputStream(new File("abc.xls"));
workbook.write(outputStream);
outputStream.close();//Close in finally if possible

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