I am using following code in my program
FileInputStream fileFile = null;
try {
fileFile = new FileInputStream(new File("D:\\work\\result\\n01jfvjnjn.xlsx"));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
XSSFWorkbook workbookFile = null;
try {
workbookFile = new XSSFWorkbook(fileFile);
} catch (IOException e) {
e.printStackTrace();
}
XSSFSheet sheetFile = workbookFile.getSheet("Sheet1");
this xlsx file has 20 sheets and each sheet has 100 rows , its some what of 5mb file . I just go to specific sheet and print the first row and first column value it takes nearly 30 secs .
much time taken in the XSSFWorkbook line . I allocated 3gb of heap and i tried below code no difference .
File file = new File("C:\\D\\Data Book.xlsx");
OPCPackage opcPackage = OPCPackage.open(file);
XSSFWorkbook workbook = new XSSFWorkbook(opcPackage);
is there any better way to do this ?
Heres a link to a number of classes, handling the big Xlsx problem in a few steps. You only need to handle the Array[String]'s you get from it and put them in a list of String Arrays.
Link: http://lchenaction.blogspot.nl/2013/12/how-to-read-super-large-excel-and-csv.html
Related
I am trying to write an excel file using java. I'm looking for just simply a column with one username per row right now, and then will build upon this later once I understand what is going a bit better. I get a zip file instead of the expected excel file, and it contains docProps, _rels, xl, and [Content_Types].xml. I don't understand how to open this zip file as though it is an excel file. I have not had luck finding the answer as all the tutorials I see show it to be a straight forward excel file, not a zip file. Is it a configuration I'm missing or is it to do with linux?
Here's my code, and what I end up with:
private void createExcelSheet(Assignment assignment) throws FileNotFoundException {
String excelFilePath = Configuration.DIRECTORY_ROOT+"/tests/"+assignment.getAssn_number()+"/gradebook-"+assignment.getAssn_number();
int rowNum = 0;
int col = 0;
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet spreadsheet = workbook.createSheet(assignment.getAssn_number()+" Grades ");
XSSFRow row = spreadsheet.createRow(rowNum);
Cell cell;
for (User user : userService.getUsers() ) {
row = spreadsheet.createRow(rowNum);
cell = row.createCell(rowNum);
cell.setCellValue(user.getStudent_id());
rowNum++;
}
try (FileOutputStream fos = new FileOutputStream(excelFilePath)) {
workbook.write(fos);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
I am trying to add some data to, already existing file which I created with; copyFileNIO(fromFile, toFile) method. To add data to already existing file I am using this code block:
try {
copyFileNIO(fromFile, toFile);
System.out.println("Copy file is done.");
// Creating file object of existing excel file
File xlsxFile = new File(toFile);
System.out.println("ok");
// Creating input stream
InputStream inputStream = new FileInputStream(xlsxFile);
System.out.println("okkk");
// Creating workbook from input stream
Workbook wb = WorkbookFactory.create(inputStream);
System.out.println("okkkk");
// Reading first sheet of excel file
Sheet sheet = wb.getSheetAt(0);
// Getting age cell of first row from the sheet
Cell cell = sheet.getRow(1).getCell(3);
// Updating the cell value with new data
cell.setCellValue(30);
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Copy file is done.");
}
However, Workbook is giving error, I tried also XSSF its not working. I do not know what causes this. You can see ambda$7 exception:
at application.Sbt.lambda$7(Sbt.java:492) -> which leads Workbook wb = WorkbookFactory.create(inputStream);
I added some System.out.println as can seen on code: output of these methods are
Copy file is done.
ok
okkk
Exception ...
How can i solve this problem ? Thank you
I confirmed my file exists and patch is correct. Changed inputstream and workbook to -> Workbook wb = WorkbookFactory.create(new File(toFile)); Still same error
full error message and stack trace
at org.apache.poi.poifs.filesystem.FileMagic.valueOf(FileMagic.java:177)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:309)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:277)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:255)
at application.Sbt.lambda$7(Sbt.java:491)
Apache POI -> 5.2.3
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 write java class to read xls file, class works fine when I read many xls file, but doesn't work if I try to read a file that I receive, and I have to read this file :(
public int readData() {
try {
excelFile = new File(excelFullFileName);
fis = new FileInputStream(excelFile);
workBook = new HSSFWorkbook(fis);
if (sheetName != null && !sheetName.equals("")) {
sheet = workBook.getSheet(sheetName);
} else {
sheet = workBook.getSheetAt(0);
sheetName = sheet.getSheetName();
}
sheetRecords.setSheetName(sheetName);
When set workBook catch exception
Exception: org.apache.poi.hssf.record.RecordInputStream$LeftoverDataException: Initialisation of record 0x203(NumberRecord) left 4 bytes remaining still to be read.
If I try to past e copy records on a new xls, java code works fine.
I think it is a file issue, but how I can read original xls file??
Help me please :(
While trying to open an excel using ApachePOI I get
org.apache.poi.openxml4j.exceptions.InvalidOperationException: Can't open the specified file: 'C:\Users\mdwaipay\AppData\Local\Temp\poifiles\poi-ooxml-1570030023.tmp'
I checked. No such folder is being created. I am using Apache POI version 3.6.
Any help? A similar code was running fine in a different workspace. At loss of thoughts here.
Code:
public Xls_Reader(String path) {
this.path=path;
try {
fis = new FileInputStream(path);
workbook = new XSSFWorkbook(fis);
sheet = workbook.getSheetAt(0);
fis.close();
}
catch (Exception e)
{ e.printStackTrace();
}
}
Why are you taking a perfectly good file, wrapping it in an InputStream, then asking POI to have to buffer the whole lot for you so it can do random access? Life is much better if you just pass the File to POI directly, so it can skip about as needed!
If you want to work with both XSSF (.xlsx) and HSSF (.xls), change your code to be
public Xls_Reader(String path) {
this.path = path;
try {
File f = new File(path);
workbook = WorkbookFactory.create(f);
sheet = workbook.getSheetAt(0);
} catch (Exception e) {
e.printStackTrace();
}
}
If you only want XSSF support, and/or you need full control of when the resources get closed, instead do something like
OPCPackage pkg = OPCPackage.open(path);
Workbook wb = new XSSFWorkbook(pkg);
// use the workbook
// When you no longer needed it, immediately close and release the file resources
pkg.close();