I am reading an excel file as a text, and I am posting this string to server. However, I couldn't convert this string to a proper data structure to use it as an input for apache poi functions without creating a temp file in the file system. What I want to do is this;
Excel String -> An Excel File Object (imaginary) -> Reading data from this imaginary file
I don't want to create a temp file every time someone tries to upload an excel file.
I tried something like this;
InputStream stream = new ByteArrayInputStream(OntologyContentTxt.getBytes(StandardCharsets.UTF_8));
HSSFWorkbook wb = new HSSFWorkbook(stream);
HSSFSheet sheet=wb.getSheetAt(0);
HSSFRow row;
HSSFCell cell;
Iterator rows = sheet.rowIterator();
while (rows.hasNext())
{
row=(HSSFRow) rows.next();
Iterator cells = row.cellIterator();
while (cells.hasNext())
{
cell=(HSSFCell) cells.next();
if (cell.getCellType() == HSSFCell.CELL_TYPE_STRING)
{
System.out.print(cell.getStringCellValue()+" ");
}
else if(cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC)
{
System.out.print(cell.getNumericCellValue()+" ");
}
}
System.out.println();
}}
But it gives me this error.
org.apache.poi.poifs.filesystem.NotOLE2FileException: Invalid header signature; read 0xE011BDBFEFBDBFEF, expected 0xE11AB1A1E011CFD0 - Your file appears not to be a valid OLE2 document
How can I make this kind of convert?
Thanks.
Related
I have an Excel spreadsheet that has the first sheet designated for the raw data. There are 3 more sheets that are coded to transform and format the data from the raw sheet. The fifth sheet has the final output.
How can I use Java:
load the data from the CSV file into the first sheet of the excel file?
save the data from the 5th sheet into the new CSV file.
Also, if the original CSV has thousands of rows, I assume the multi-sheet transformations would take some time before the 5th sheet gets all the final data - is there a way to know?
I would follow this approach:
Load the specific .csv file and prepare to read it with Java
Load the .xlsx file and change it according to your requirements and the data that you get from the .csv file. A small example of how an excel file is changed with Apache POI can be seen below:
try
{
HashMap<Integer, ArrayList<String>> fileData; // This for example keeps the data from the csv in this form ( 0 -> [ "Column1", "Column2" ]...)
// Working with the excel file now
FileInputStream file = new FileInputStream("Data.xlsx");
XSSFWorkbook workbook = new XSSFWorkbook(file); // getting the Workbook
XSSFSheet sheet = workbook.getSheetAt(0);
Cell cell = null;
AtomicInteger row = new AtomicInteger(0);
fileData.forEach((key, csvRow) ->
{
//Update the value of the cell
//Retrieve the row and check for null
HSSFRow sheetRow = sheet.getRow(row);
if(sheetRow == null)
{
sheetRow = sheet.createRow(row);
}
for (int i = 0; i < csvRow.size(); i++)
{
//Update the value of cell
cell = sheetRow.getCell(i);
if(cell == null){
cell = sheetRow.createCell(i);
}
cell.setCellValue(csvRow.get(i));
}
});
file.close();
FileOutputStream outFile =new FileOutputStream(new File("Data.xlsx"));
workbook.write(outFile);
outFile.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
After saving the .xlsx file, you can create the .csv file by following this question.
I am trying to read column values from excel file which looks like this
This is my code for reading excel file
Xls_Reader d = new Xls_Reader("C:\\TestData.xlsx");
System.out.println(d.getRowCount("sheetname"));
String s1 = String.valueOf(d.getCellData("TC03", "Contract_ID",3));
s1 =(int)Double.parseDouble(s1) + "";
System.out.println(s1);
in this code i am able to get record of one row. But i need to print all the Row value.
Please suggest.
What Jars you are using for this approach?
I have following code to read data from excel using apache poi -
public static void main(String args[]) throws IOException
{
FileInputStream fis = new FileInputStream(new File("your_file.xlsx"));
XSSFWorkbook workbook = new XSSFWorkbook(fis); // XSSFWorkbook for .xlsx file
XSSFSheet sheet = workbook.getSheetAt(0); // open sheet 1
Iterator<Row> rowIterator = sheet.iterator();
// Traversing over each row of XLSX file
while (rowIterator.hasNext())
{
Row row = rowIterator.next();
if(row.getRowNum()!=0) // skip title row
{
Iterator cellIterator = row.cellIterator();
while (cellIterator.hasNext())
{
Cell cell = (Cell) cellIterator.next();
System.out.print(cell.getStringCellValue() + "\t");
}
}
}
}
Note :- In my case cell in excel sheet formatted as text you can change cell.getStringCellValue() method as per your data.
This method will be print all sheet of your excel document:
public static void GetEmail() throws IOException{
InputStream in = new FileInputStream("C:/path to your doc");
HSSFWorkbook wb = new HSSFWorkbook(in);
ExcelExtractor extractor = new ExcelExtractor(wb);
extractor.setFormulasNotResults(false); // Read formulas
extractor.setIncludeSheetNames(false);
String text = extractor.getText();
System.out.println(text);
}
I am trying to update an existing Excel with Apache POI.
The thing is, I have an excel having in its 3rd column telephone numbers, and I want to correct them to the specific format using if-statements.
But I cannot write to the file.
Here is the code I am using:
public void readingExcel(String fileName) throws Exception {
try (FileInputStream file = new FileInputStream(new File(fileName))) {
HSSFWorkbook workbook = new HSSFWorkbook(file);
HSSFSheet sheet = workbook.getSheetAt(0);
Iterator<Row> rowIterator = sheet.iterator();
int counter = 0;
for (Row row : sheet) {
int columnIndex = 2;
row = CellUtil.getRow(counter, sheet);
Cell cell = CellUtil.getCell(row, columnIndex);
if (formatter.formatCellValue(cell).length() == 8)
cell.setCellValue("+216" + formatter.formatCellValue(cell));
if (formatter.formatCellValue(cell).length() == 11 && formatter.formatCellValue(cell).startsWith("216"))
cell.setCellValue("+" + formatter.formatCellValue(cell));
counter++;
}
FileOutputStream outFile =new FileOutputStream(new File(fileName));
workbook.write(outFile);
outFile.close();
}
}
And I am getting this error
org.apache.poi.poifs.filesystem.NotOLE2FileException: Invalid header signature; read 0x0000000000000000, expected 0xE11AB1A1E011CFD0 - Your file appears not to be a valid OLE2 document
at org.apache.poi.poifs.storage.HeaderBlock.<init>(HeaderBlock.java:181)
at org.apache.poi.poifs.storage.HeaderBlock.<init>(HeaderBlock.java:140)
at org.apache.poi.poifs.filesystem.NPOIFSFileSystem.<init>(NPOIFSFileSystem.java:302)
at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:398)
at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:379)
at excelapp.myClass.readingExcel(myClass.java:50)
at excelapp.myClass.<init>(myClass.java:41)
at excelapp.ExcelApp.main(ExcelApp.java:26)
The thing is that it is really important for today, and I am getting really stuck on updating the values of that column :-/ anyone has an idea? I think I'm writing the wrong way..
I am reading excel file using Apache POI in gwt using java. I have one excel file with 15000 records and four columns Count, Name, Mob No and EmailID. I am uploading excel file in blobstore GAE then I am reading that excel file. I am just checking with logger all data is reading or not. when I deployed and test then only last 266 rows are reading and displayed in logger. Why? how to read all data from excel. my code is:
HSSFWorkbook workbook = new HSSFWorkbook(newBlobstoreInputStream(blobkey));
HSSFSheet sheet = workbook.getSheetAt(0);
Iterator<Row> rowIterator = sheet.iterator();
// Traversing over each row of XLSX file
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
// For each row, iterate through each columns
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
switch (cell.getCellType()) {
case Cell.CELL_TYPE_STRING:
logger.log(Level.SEVERE,cell.getStringCellValue() + "\t");
break;
case Cell.CELL_TYPE_NUMERIC:
logger.log(Level.SEVERE,cell.getNumericCellValue() + "\t");
break;
case Cell.CELL_TYPE_BOOLEAN:
logger.log(Level.SEVERE,cell.getBooleanCellValue() +"\t");
break;
default :
}
}
System.out.println("");
}
how shall i read all data from start to end?
any help Thanks in advance
And One more is when i change XSSFWorkbook and XSSFSheet instead of HSSFWorkbook and HSSFSheet to read Xlsx excel then its throw Exception : org.apache.poi.poifs.filesystem.OfficeXmlFileException: The supplied data appears to be in the Office 2007+ XML. You are calling the part of POI that deals with OLE2 Office Documents. how can i fix this
Any help
Thanks in advance.
For the exception you are getting, .xls files are read by HSSFWorkbook & HSSFSheet whereas .xlsx are read by XSSFWorkbook & XSSFSheet.
You can use the Factory class to get the appropriate Workbook if you are goin to handle both .xls & .xlsx format.
I try to read this excel file: Test.xlsx, to do this I used an example I found on the internet, but
I used this link as en example: http://howtodoinjava.com/2013/06/19/readingwriting-excel-files-in-java-poi-tutorial/
it doens't work.
I copied the url for the file, so there is no error there.
Whenever I run it, it doensnt show errors just : []
When I debug it, it shows me that the listsize = 0
What should I change?
ArrayList<String> list = new ArrayList<String>();
#Override
public List<String> getExcel(){
try {
FileInputStream file = new FileInputStream(new File("C:\\Users\\user\\Documents\\Test.xlsx"));
//Create Workbook instance holding reference to .xlsx file
HSSFWorkbook workbook = new HSSFWorkbook(file);
//Get first/desired sheet from the workbook
HSSFSheet sheet = workbook.getSheet("Sheet1");
//Iterate through each rows one by one
Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
//For each row, iterate through all the columns
if (row.getRowNum() <= 7) {
continue;// skip to read the first 7 row of file
}
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
list.add(cell.getStringCellValue());
}
//System.out.println("");
}
file.close();
} catch (Exception e) {
e.printStackTrace();
}
return list;
}
You are using the wrong class for the file you are trying to open (Test.xlsx). By the extension, I can assume this is an Excel 2007 or later document. Use HSSFWorkbook for Excel 2003 and XSSFWorkbook for Excel 2007 or later. Review Apache POI documentation that came with the downloaded package. It contains basic tutorials on how to accomplish this.
You will need to replace all of the 'HSSF' classes for the 'XSSF' equivalent. Beware that the methods called to create the parts of the document (i.e. Workbook, Sheet, etc) are not always the same.
Try this link. I created a small demo for a simple tutorial on Apache POI some time back. There is an Excel example you could follow. The location contains source code and a set of slides that you should be able to follow easily.