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reading from excel using Java poi 4.11

Why it outputs an error"Exception in thread "main" java.lang.IllegalArgumentException: Sheet index (0) is out of range (no sheets)"
import org.apache.poi.ss.usermodel.Workbook;
import java.io.FileInputStream;
import java.io.IOException;
public class test {
public static void main(String[] args) throws IOException {
Workbook wb = new HSSFWorkbook();
FileInputStream fis = new FileInputStream("C:/Users/KP/IdeaProjects/JavaExcel/read.xls");
String result = wb.getSheetAt(1).getRow(1).getCell(1).getStringCellValue();
System.out.println(result);
fis.close();
}
}

You created a new Workbook and access the sheet at Index 1.
If you want to load your Inputstream to your workbook you need to create a new Workbook with the InputStream.
You should also use try with resources to close your stream and workbook.
try (InputStream in = new FileInputStream("C:/Users/KP/IdeaProjects/JavaExcel/read.xls");
Workbook wb = new HSSFWorkbook(in)) {
String result = wb.getSheetAt(1).getRow(1).getCell(1).getStringCellValue();
System.out.println(result);
}
Please notice that getSheetAt(1) returns the second sheet. If you want the first sheet you need to use getSheetAt(0). Same goes for getRow and getCell. So if you want the first cell in the first row in the first workbook use:
String result = wb.getSheetAt(0).getRow(0).getCell(0).getStringCellValue();

declare/ Initialize the workbook after file input stream like below by passing fis object
FileInputStream fis = new FileInputStream("C:/Users/KP/IdeaProjects/JavaExcel/read.xls");
Workbook wb = new HSSFWorkbook(fis);
hope you have data in the second sheet of excel file as mentioned "wb.getSheetAt(1)", if not make it wb.getSheetAt(0)

How to close XSSF file with out.close()?

I am trying to save and close an existing workbook that I am already successfully opening but for some reason cannot either save and close:
//declarations etc here...
try {
InputStream ExcelFileToRead = new FileInputStream(file);
XSSFWorkbook wb = new XSSFWorkbook(ExcelFileToRead);
//XSSFWorkbook wb = new XSSFWorkbook(new FileInputStream(new File(file)));
XSSFSheet sheet = wb.getSheetAt(0);
XSSFRow row;
XSSFCell cell;
int rows;
rows = sheet.getPhysicalNumberOfRows();
int cols = 1;
XSSFRichTextString path;
String stpath;
try {
if(!Desktop.isDesktopSupported()){
System.out.println("Error: Desktop is not supported");
}
Desktop desktop = Desktop.getDesktop();
if(filee.exists()) desktop.open(filee);
FileOutputStream out = new FileOutputStream(file);
wb.write(out);
out.close();
//code continues...
wb.write(out) opens the file successfully. I have read tons of posts/articles/docs all using that close() method to close out an XSSF Excel file but it does not work here.
How do I solve the problem?

You cannot overwrite the input document this way, as clearly documented in the Javadoc for POIXMLDocument#write(OutputStream o) which is inherited by XSSFWorkBook:
Note - if the Document was opened from a File rather than an InputStream, you must write out to a different file, overwriting via an OutputStream isn't possible

Appending sheet to existing excel file using Java and Apache POI

I have a Java method writeToExcel(String sheetName, Map), which creates a new sheet with name 'sheetName' in a new excel file and write the map data into it . When I call the method with different sheetName arguments more than once, existing sheet gets replaced by the last called one. I want to create new sheets in the same excel file each time whenever the method is called with different sheetName argument, without losing existing sheets. Here is my code.
public static void writeToExcel(String fileName,Map<Integer,String[]> excelData){
String filePath="/Data/excel.xlsx";
XSSFWorkbook workbook=new XSSFWorkbook();
XSSFSheet sheet=workbook.createSheet(fileName);
Set<Integer> keySet=excelData.keySet();
int passedCount=0;
int failedCount=0;
int rowNo=0;
int cellNo=0;
Row row;
Cell cell;
try{
File file=new File(filePath);
FileOutputStream output=new FileOutputStream(file);
for(Integer key:keySet){
row=sheet.createRow(rowNo++);
String[] dataToWrite=excelData.get(key);
cellNo=0;
for(String str:dataToWrite){
cell=row.createCell(cellNo++);
cell.setCellValue(str);
}
}
workbook.write(output);
output.close();
workbook.close();
}
catch(FileNotFoundException e){
e.printStackTrace();
}
catch(IOException e){
e.printStackTrace();
}
}

Seems like you're always creating a new workbook in the second line of the method. So it is not the sheet that is replaced but the entire workbook. Better use
XSSFWorkbook workbook=new XSSFWorkbook(new File(filePath));
That should do the trick.

XSSFWorkbook workbook=new XSSFWorkbook(new File(filePath)); => XSSFWorkbook workbook=new XSSFWorkbook(filePath); as no suit constructor for XSSFWorkbook workbook=new XSSFWorkbook(new File(filePath))

Delete an excel sheet using Apache POI

I have to delete a sheet from the Excel file.
Here's my code snippet :
FileInputStream fileStream = new FileInputStream(destFile);
POIFSFileSystem fsPoi = new POIFSFileSystem(fileStream);
HSSFWorkbook workbook = new HSSFWorkbook(fsPoi);
int index = 0;
HSSFSheet sheet = workbook.getSheet("Setup");
if(sheet != null) {
index = workbook.getSheetIndex(sheet);
workbook.removeSheetAt(index);
}
return destFile;
After this I'm getting exactly the same workbook which I passed, without the removal of the sheet "Setup"
Help me resolve this. Any help would be appreciated

After editing your workbook, you need to write it again. Try this:-
FileOutputStream output = new FileOutputStream(destFile);
workbook.write(output);
output.close();
Edit:- After writing it back, you can return your destFile.

private void removeOtherSheets(String sheetName, XSSFWorkbook book) {
for(int i=book.getNumberOfSheets()-1;i>=0;i--){
XSSFSheet tmpSheet =book.getSheetAt(i);
if(!tmpSheet.getSheetName().equals(sheetName)){
book.removeSheetAt(i);
}
}
}

Delete a sheet using Apache POI
//Open file
FileInputStream inputStream = new FileInputStream(new File(filePath));
XSSFWorkbook workBook = new XSSFWorkbook(inputStream);
//Delete Sheet
workBook.removeSheetAt(resultWorkbook.getSheetIndex("SheetToBeDeleted"));
//Save the file
FileOutputStream outFile =new FileOutputStream(new File(filePath));
workBook.write(filePath);
outFile.close();

Java POI Create new Workbook with SS model?

I'm a little confused, I used to do this:
HSSFWorkbook wb = new HFFSWorkbook();
But with the new POI, I dont have to do that.
I can't do this:
Workbook wb = new Workbook();
I understand WorkbookFactory.create, but that is for opening a file.
How do I set up a new workbook with this ss model?

You can still use the SS model but need to decide on the file format at the time of creation.
For xls -> Workbook wb = new HSSFWorkbook();
For xlsx -> Workbook wb = new XSSFWorkbook();

In "New POI", you can write/read both XLS files and XLSX files. In any case, for XLS file-format you were using:
HSSFWorkbook wb = new HSSFWorkbook();
So for XLSX file-format, you have to use:
XSSFWorkbook wb = new XSSFWorkbook();
// you could also do below
// Workbook wb = new XSSFWorkbook();
Also it would be helpful for you if you refer below links for starting with XLS to XLSX migration.
1. http://poi.apache.org/apidocs/org/apache/poi/xssf/usermodel/XSSFWorkbook.html
2. http://poi.apache.org/spreadsheet/converting.html

Make sure you download and add the POI JAR file to your project’s class path before running the code. The Apache POI JAR file can be found here.
public void main(String[] args) throws IOException {
// Directory path where the xls file will be created
String destinationFilePath = "C:/Users/devesh_/Documents/HelloWorld.xls";
// Create object of FileOutputStream
FileOutputStream fout = new FileOutputStream(destinationFilePath);
// Build the Excel File
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
HSSFWorkbook workBook = new HSSFWorkbook();
// Create the spreadsheet
HSSFSheet spreadSheet = workBook.createSheet("Hello_World");
// Create the first row
HSSFRow row = spreadSheet.createRow((short) 0);
// Create the cells and write to the file
HSSFCell cell;
// Write Hello
cell = row.createCell(0);
cell.setCellValue(new HSSFRichTextString("Hello"));
// Write World
cell = row.createCell(1);
cell.setCellValue(new HSSFRichTextString("World"));
workBook.write(outputStream);
outputStream.writeTo(fout);
outputStream.close();
fout.close();
}

When creating a file, you need to decide up front what format it'll be - you can't just wait until write-out time to do that. You code would be something like:
Workbook wb = null;
if (shouldBeXLS) {
wb = new HSSFWorkbook();
} else {
wb = new XSSFWorkbook();
}
// work on the file in a generic way
// save, with a suitable name
String filename = "test.xls";
if (!shouldBeXLS) { filename = filename + "x"; }
FileOutputStream fout = new FileOutputStream(filename);
wb.write(fout);
fout.close();
At the start, decide what format you want for this particular instance, and create that. Treat it as a general workbook, and write to it in the common way. At the end, remember what it is so you can give the file the right extension!
(When reading a file in, WorkbookFactory will let you load the appropriate instance for the file type. When creating a new file, you have to pick yourself as there's nothing there yet!)