Java and excel programming

How to read and write excel file

I want to read and write an Excel file from Java with 3 columns and N rows, printing one string in each cell. Can anyone give me simple code snippet for this? Do I need to use any external lib or does Java have built-in support for it? I want to do the following:

With GemBox.Spreadsheet for Java this is simple, you just iterate through rows in a sheet and through allocated cells in a row and call ExcelCell.getValue() on each. For instance, see this reading example, also for writing you can check this example.

23 Answers 23

Try the Apache POI HSSF. Here’s an example on how to read an excel file:

try < POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(file)); HSSFWorkbook wb = new HSSFWorkbook(fs); HSSFSheet sheet = wb.getSheetAt(0); HSSFRow row; HSSFCell cell; int rows; // No of rows rows = sheet.getPhysicalNumberOfRows(); int cols = 0; // No of columns int tmp = 0; // This trick ensures that we get the data properly even if it doesn't start from first few rows for(int i = 0; i < 10 || i < rows; i++) < row = sheet.getRow(i); if(row != null) < tmp = sheet.getRow(i).getPhysicalNumberOfCells(); if(tmp >cols) cols = tmp; > > for(int r = 0; r < rows; r++) < row = sheet.getRow(r); if(row != null) < for(int c = 0; c < cols; c++) < cell = row.getCell((short)c); if(cell != null) < // Your code here >> > > > catch(Exception ioe)

On the documentation page you also have examples of how to write to excel files.

In my attempts to use this code, I found that HSSFSheet ‘s getPhysicalNumberOfRows() method seemed to return the number of non-empty rows (it was not obvious to me that’s what «physical» meant). So, if your excel file has a lot of empty rows (i.e. for formatting reasons), you might have more luck using rows = sheet.getLastRowNum(); . This should also mean you can remove the trick (see comment) from the first loop: for(int i = 0; i

Sorry to dig this again but i has the same problem as this, Let say you have 3 column of Name, BirthDate, Gender. How do you add that 3 to separate Vector by reading with this code?

Apache POI can do this for you. Specifically the HSSF module. The quick guide is most useful. Here’s how to do what you want — specifically create a sheet and write it out.

Workbook wb = new HSSFWorkbook(); //Workbook wb = new XSSFWorkbook(); CreationHelper createHelper = wb.getCreationHelper(); Sheet sheet = wb.createSheet("new sheet"); // Create a row and put some cells in it. Rows are 0 based. Row row = sheet.createRow((short)0); // Create a cell and put a value in it. Cell cell = row.createCell(0); cell.setCellValue(1); // Or do it on one line. row.createCell(1).setCellValue(1.2); row.createCell(2).setCellValue( createHelper.createRichTextString("This is a string")); row.createCell(3).setCellValue(true); // Write the output to a file FileOutputStream fileOut = new FileOutputStream("workbook.xls"); wb.write(fileOut); fileOut.close(); 

If you’re using Spring it’s not plain Java. I think that if you want to read these files then POI is the way forwards

First add all these jar files in your project class path:

1. poi-scratchpad-3.7-20101029
2. poi-3.2-FINAL-20081019
3. poi-3.7-20101029
4. poi-examples-3.7-20101029
5. poi-ooxml-3.7-20101029
6. poi-ooxml-schemas-3.7-20101029
7. xmlbeans-2.3.0
8. dom4j-1.6.1

Code for writing in a excel file:

public static void main(String[] args) < //Blank workbook XSSFWorkbook workbook = new XSSFWorkbook(); //Create a blank sheet XSSFSheet sheet = workbook.createSheet("Employee Data"); //This data needs to be written (Object[]) Mapdata = new TreeMap(); data.put("1", new Object[]); data.put("2", new Object[]); data.put("3", new Object[]); data.put("4", new Object[]); data.put("5", new Object[]); //Iterate over data and write to sheet Set keyset = data.keySet(); int rownum = 0; for (String key : keyset) < //create a row of excelsheet Row row = sheet.createRow(rownum++); //get object array of prerticuler key Object[] objArr = data.get(key); int cellnum = 0; for (Object obj : objArr) < Cell cell = row.createCell(cellnum++); if (obj instanceof String) < cell.setCellValue((String) obj); >else if (obj instanceof Integer) < cell.setCellValue((Integer) obj); >> > try < //Write the workbook in file system FileOutputStream out = new FileOutputStream(new File("C:\\Documents and Settings\\admin\\Desktop\\imp data\\howtodoinjava_demo.xlsx")); workbook.write(out); out.close(); System.out.println("howtodoinjava_demo.xlsx written successfully on disk."); >catch (Exception e) < e.printStackTrace(); >> 

Code for reading from excel file

/* * To change this template, choose Tools | Templates * and open the template in the editor. */ public static void main(String[] args) < try < FileInputStream file = new FileInputStream(new File("C:\\Documents and Settings\\admin\\Desktop\\imp data\\howtodoinjava_demo.xlsx")); //Create Workbook instance holding reference to .xlsx file XSSFWorkbook workbook = new XSSFWorkbook(file); //Get first/desired sheet from the workbook XSSFSheet sheet = workbook.getSheetAt(0); //Iterate through each rows one by one IteratorrowIterator = sheet.iterator(); while (rowIterator.hasNext()) < Row row = rowIterator.next(); //For each row, iterate through all the columns IteratorcellIterator = row.cellIterator(); while (cellIterator.hasNext()) < Cell cell = cellIterator.next(); //Check the cell type and format accordingly switch (cell.getCellType()) < case Cell.CELL_TYPE_NUMERIC: System.out.print(cell.getNumericCellValue() + "\t"); break; case Cell.CELL_TYPE_STRING: System.out.print(cell.getStringCellValue() + "\t"); break; >> System.out.println(""); > file.close(); > catch (Exception e) < e.printStackTrace(); >> 

You can also consider JExcelApi. I find it better designed than POI. There’s a tutorial here.

JExcelApi is for old (up to Excel 2003) binary .xls files. Apache POI-HSSF is addressing the same old .xls, while Apache POI-XSSF works with the new (Excel 2007-) .xlsx

The disadvantage is that it only provides support for processing Excel files in the .xls (1997-2003) format.

There is a new easy and very cool tool (10x to Kfir): xcelite

public class User < @Column (name="Firstname") private String firstName; @Column (name="Lastname") private String lastName; @Column private long id; @Column private Date birthDate; >Xcelite xcelite = new Xcelite(); XceliteSheet sheet = xcelite.createSheet("users"); SheetWriter writer = sheet.getBeanWriter(User.class); List users = new ArrayList(); // . fill up users writer.write(users); xcelite.write(new File("users_doc.xlsx")); 

Xcelite xcelite = new Xcelite(new File("users_doc.xlsx")); XceliteSheet sheet = xcelite.getSheet("users"); SheetReader reader = sheet.getBeanReader(User.class); Collection users = reader.read(); 

For reading a xlsx file we can use Apache POI libs Try this:

public static void readXLSXFile() throws IOException < InputStream ExcelFileToRead = new FileInputStream("C:/Test.xlsx"); XSSFWorkbook wb = new XSSFWorkbook(ExcelFileToRead); XSSFWorkbook test = new XSSFWorkbook(); XSSFSheet sheet = wb.getSheetAt(0); XSSFRow row; XSSFCell cell; Iterator rows = sheet.rowIterator(); while (rows.hasNext()) < row=(XSSFRow) rows.next(); Iterator cells = row.cellIterator(); while (cells.hasNext()) < cell=(XSSFCell) cells.next(); if (cell.getCellType() == XSSFCell.CELL_TYPE_STRING) < System.out.print(cell.getStringCellValue()+" "); >else if(cell.getCellType() == XSSFCell.CELL_TYPE_NUMERIC) < System.out.print(cell.getNumericCellValue()+" "); >else < //U Can Handel Boolean, Formula, Errors >> System.out.println(); > > 

.csv or POI will certainly do it, but you should be aware of Andy Khan’s JExcel. I think it’s by far the best Java library for working with Excel there is.

A simple CSV file should suffice

Indeed CSV is enough. If your fields have no commas, it is probably easiest just to print the fields and commas. Otherwise, you may want to use commons.apache.org/sandbox/csv

I’m not sure a CSV is enough, since the question specifically says ‘read’ and ‘write’ an Excel file. He might be able to get away with CSV, but that’s not what he’s asking.

Some international versions of Excel use semicolons instead of commas as separators. This also increases complexity

String path="C:\\Book2.xlsx"; try < File f = new File( path ); Workbook wb = WorkbookFactory.create(f); Sheet mySheet = wb.getSheetAt(0); IteratorrowIter = mySheet.rowIterator(); for ( Iterator rowIterator = mySheet.rowIterator() ;rowIterator.hasNext(); ) < for ( IteratorcellIterator = ((Row)rowIterator.next()).cellIterator() ; cellIterator.hasNext() ; ) < System.out.println ( ( (Cell)cellIterator.next() ).toString() ); >System.out.println( " **************************************************************** "); > > catch ( Exception e )

and make sure to have added the jars poi and poi-ooxml (org.apache.poi) to your project

For reading data from .xlsx workbooks we need to use XSSFworkbook classes.

XSSFWorkbook xlsxBook = new XSSFWorkbook(fis);

XSSFSheet sheet = xlsxBook.getSheetAt(0); etc.

We need to use Apache-poi 3.9 @ http://poi.apache.org/

For detailed info with example visit : http://java-recent.blogspot.in

With Apache POI you need HSSF module for XLS and XSSF module for XLSX format, with GemBox.Spreadsheet for Java both formats are unified into same module and are represented with same ExcelFile type.

Sure , you will find the code below useful and easy to read and write. This is a util class which you can use in your main method and then you are good to use all methods below.

 public class ExcelUtils < private static XSSFSheet ExcelWSheet; private static XSSFWorkbook ExcelWBook; private static XSSFCell Cell; private static XSSFRow Row; File fileName = new File("C:\\Users\\satekuma\\Pro\\Fund.xlsx"); public void setExcelFile(File Path, String SheetName) throws Exception try < FileInputStream ExcelFile = new FileInputStream(Path); ExcelWBook = new XSSFWorkbook(ExcelFile); ExcelWSheet = ExcelWBook.getSheet(SheetName); >catch (Exception e) < throw (e); >> public static String getCellData(int RowNum, int ColNum) throws Exception < try < Cell = ExcelWSheet.getRow(RowNum).getCell(ColNum); String CellData = Cell.getStringCellValue(); return CellData; >catch (Exception e) < return ""; >> public static void setCellData(String Result, int RowNum, int ColNum, File Path) throws Exception < try < Row = ExcelWSheet.createRow(RowNum - 1); Cell = Row.createCell(ColNum - 1); Cell.setCellValue(Result); FileOutputStream fileOut = new FileOutputStream(Path); ExcelWBook.write(fileOut); fileOut.flush(); fileOut.close(); >catch (Exception e) < throw (e); >> > 

using spring apache poi repo

if (fileName.endsWith(".xls")) < File myFile = new File("file location" + fileName); FileInputStream fis = new FileInputStream(myFile); org.apache.poi.ss.usermodel.Workbook workbook = null; try < workbook = WorkbookFactory.create(fis); >catch (InvalidFormatException e) < e.printStackTrace(); >org.apache.poi.ss.usermodel.Sheet sheet = workbook.getSheetAt(0); Iterator rowIterator = sheet.iterator(); while (rowIterator.hasNext()) < Row row = rowIterator.next(); IteratorcellIterator = row.cellIterator(); while (cellIterator.hasNext()) < Cell cell = cellIterator.next(); switch (cell.getCellType()) < case Cell.CELL_TYPE_STRING: System.out.print(cell.getStringCellValue()); break; case Cell.CELL_TYPE_BOOLEAN: System.out.print(cell.getBooleanCellValue()); break; case Cell.CELL_TYPE_NUMERIC: System.out.print(cell.getNumericCellValue()); break; >System.out.print(" - "); > System.out.println(); > > 

I edited the most voted one a little cuz it didn’t count blanks columns or rows well not totally, so here is my code i tested it and now can get any cell in any part of an excel file. also now u can have blanks columns between filled column and it will read them

 try < POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(Dir)); HSSFWorkbook wb = new HSSFWorkbook(fs); HSSFSheet sheet = wb.getSheetAt(0); HSSFRow row; HSSFCell cell; int rows; // No of rows rows = sheet.getPhysicalNumberOfRows(); int cols = 0; // No of columns int tmp = 0; int cblacks=0; // This trick ensures that we get the data properly even if it doesn't start from first few rows for(int i = 0; i = cols) cols = tmp;else > cols++; > cols=cols+cblacks; for(int r = 0; r < rows; r++) < row = sheet.getRow(r); if(row != null) < for(int c = 0; c < cols; c++) < cell = row.getCell(c); if(cell != null) < System.out.print(cell+"\n");//Your Code here >> > >> catch(Exception ioe)

If column number are varing you can use this

package com.org.tests; import org.apache.poi.xssf.usermodel.*; import java.io.FileInputStream; import java.io.IOException; public class ExcelSimpleTest < String path; public FileInputStream fis = null; private XSSFWorkbook workbook = null; private XSSFSheet sheet = null; private XSSFRow row =null; private XSSFCell cell = null; public ExcelSimpleTest() throws IOException < path = System.getProperty("user.dir")+"\\resources\\Book1.xlsx"; fis = new FileInputStream(path); workbook = new XSSFWorkbook(fis); sheet = workbook.getSheetAt(0); >public void ExelWorks() < int index = workbook.getSheetIndex("Sheet1"); sheet = workbook.getSheetAt(index); int rownumber=sheet.getLastRowNum()+1; for (int i=1; i> > public static void main(String[] args) throws IOException < ExcelSimpleTest excelwork = new ExcelSimpleTest(); excelwork.ExelWorks(); >> 

The corresponding mavendependency can be found here

Another way to read/write Excel files is to use Windmill. It provides a fluent API to process Excel and CSV files.

Import data

try (Stream rowStream = Windmill.parse(FileSource.of(new FileInputStream("myFile.xlsx")))) < rowStream // skip the header row that contains the column names .skip(1) .forEach(row ->< System.out.println( "row n°" + row.rowIndex() + " column 'User login' value : " + row.cell("User login").asString() + " column n°3 number value : " + row.cell(2).asDouble().value() // index is zero-based ); >); > 

Export data

Windmill .export(Arrays.asList(bean1, bean2, bean3)) .withHeaderMapping( new ExportHeaderMapping() .add("Name", Bean::getName) .add("User login", bean -> bean.getUser().getLogin()) ) .asExcel() .writeTo(new FileOutputStream("Export.xlsx")); 

You need Apache POI library and this code below should help you

 import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; import java.util.List; import java.util.Iterator; //************************************************************* import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.xssf.usermodel.XSSFSheet; import org.apache.poi.xssf.usermodel.XSSFWorkbook; //************************************************************* public class AdvUse < private static Workbook wb ; private static Sheet sh ; private static FileInputStream fis ; private static FileOutputStream fos ; private static Row row ; private static Cell cell ; private static String ExcelPath ; //************************************************************* public static void setEcxelFile(String ExcelPath, String SheetName) throws Exception < try < File f= new File(ExcelPath); if(!f.exists())< f.createNewFile(); System.out.println("File not Found so created"); >fis = new FileInputStream("./testData.xlsx"); wb = WorkbookFactory.create(fis); sh = wb.getSheet("SheetName"); if(sh == null) < sh = wb.getSheet(SheetName); >>catch(Exception e) > //************************************************************* public static void setCellData(String text , int rowno , int colno) < try< row = sh.getRow(rowno); if(row == null)< row = sh.createRow(rowno); >cell = row.getCell(colno); if(cell!=null) < cell.setCellValue(text); >else < cell = row.createCell(colno); cell.setCellValue(text); >fos = new FileOutputStream(ExcelPath); wb.write(fos); fos.flush(); fos.close(); >catch(Exception e) < System.out.println(e.getMessage()); >> //************************************************************* public static String getCellData(int rowno , int colno) < try< cell = sh.getRow(rowno).getCell(colno); String CellData = null ; switch(cell.getCellType())< case STRING : CellData = cell.getStringCellValue(); break ; case NUMERIC : CellData = Double.toString(cell.getNumericCellValue()); if(CellData.contains(".o"))< CellData = CellData.substring(0,CellData.length()-2); >break ; case BLANK : CellData = ""; break ; > return CellData; >catch(Exception e) > //************************************************************* public static int getLastRow()

You can not read & write same file in parallel(Read-write lock). But, we can do parallel operations on temporary data(i.e. Input/output stream). Write the data to file only after closing the input stream. Below steps should be followed.

• Open the file to Input stream
• Open the same file to an Output Stream
• Read and do the processing
• Write contents to output stream.
• Close the read/input stream, close file
• Close output stream, close file.

Apache POI — read/write same excel example

import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.sql.Date; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Set; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.xssf.usermodel.XSSFSheet; import org.apache.poi.xssf.usermodel.XSSFWorkbook; public class XLSXReaderWriter < public static void main(String[] args) < try < File excel = new File("D://raju.xlsx"); FileInputStream fis = new FileInputStream(excel); XSSFWorkbook book = new XSSFWorkbook(fis); XSSFSheet sheet = book.getSheetAt(0); Iteratoritr = sheet.iterator(); // Iterating over Excel file in Java while (itr.hasNext()) < Row row = itr.next(); // Iterating over each column of Excel file IteratorcellIterator = row.cellIterator(); while (cellIterator.hasNext()) < Cell cell = cellIterator.next(); switch (cell.getCellType()) < case Cell.CELL_TYPE_STRING: System.out.print(cell.getStringCellValue() + "\t"); break; case Cell.CELL_TYPE_NUMERIC: System.out.print(cell.getNumericCellValue() + "\t"); break; case Cell.CELL_TYPE_BOOLEAN: System.out.print(cell.getBooleanCellValue() + "\t"); break; default: >> System.out.println(""); > // writing data into XLSX file Map newData = new HashMap(); newData.put("1", new Object[] < 1d, "Raju", "75K", "dev", "SGD" >); newData.put("2", new Object[] < 2d, "Ramesh", "58K", "test", "USD" >); newData.put("3", new Object[] < 3d, "Ravi", "90K", "PMO", "INR" >); Set newRows = newData.keySet(); int rownum = sheet.getLastRowNum(); for (String key : newRows) < Row row = sheet.createRow(rownum++); Object[] objArr = newData.get(key); int cellnum = 0; for (Object obj : objArr) < Cell cell = row.createCell(cellnum++); if (obj instanceof String) < cell.setCellValue((String) obj); >else if (obj instanceof Boolean) < cell.setCellValue((Boolean) obj); >else if (obj instanceof Date) < cell.setCellValue((Date) obj); >else if (obj instanceof Double) < cell.setCellValue((Double) obj); >> > // open an OutputStream to save written data into Excel file FileOutputStream os = new FileOutputStream(excel); book.write(os); System.out.println("Writing on Excel file Finished . "); // Close workbook, OutputStream and Excel file to prevent leak os.close(); book.close(); fis.close(); > catch (FileNotFoundException fe) < fe.printStackTrace(); >catch (IOException ie) < ie.printStackTrace(); >> > 

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