Exporting JTable Data including Table Headers to Excel File - java

I need help regarding this, I can't get it right. I want to export JTable data to excel file. There is no error but I am getting only the data it shows and does not include the table headers.
I am running this in a Netbeans 8.2 IDE and had also imported the essential jar files.
Data on my jtable is provided by my mysql database and I need to export it from jtable to an excel file.
Anyway tblData is my JTable variable name.
private void btnExportActionPerformed(java.awt.event.ActionEvent evt) {
FileOutputStream excelFOS = null;
BufferedOutputStream excelBOS = null;
XSSFWorkbook wb = null;
JFileChooser excelFileChooser = new JFileChooser();
excelFileChooser.setDialogTitle("Save As");
FileNameExtensionFilter fnef = new FileNameExtensionFilter("Excel Files","xls","xlsx","ods");
excelFileChooser.setFileFilter(fnef);
int excelChooser = excelFileChooser.showSaveDialog(null);
if(excelChooser == JFileChooser.APPROVE_OPTION){
try {
wb = new XSSFWorkbook();
XSSFSheet sheet = wb.createSheet("Data Sheet");
for(int i = 0; i < tblData.getRowCount(); i++){
XSSFRow excelRow = sheet.createRow(i);
for(int j = 0; j < tblData.getColumnCount(); j++){
XSSFCell excelCell = excelRow.createCell(j);
excelCell.setCellValue(tblData.getValueAt(i, j).toString());
}
}
excelFOS = new FileOutputStream(excelFileChooser.getSelectedFile() + ".xlsx");
excelBOS = new BufferedOutputStream(excelFOS);
wb.write(excelBOS);
JOptionPane.showMessageDialog(null, "Successfully saved.");
} catch (FileNotFoundException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
if(excelBOS != null){
excelBOS.close();
}
if(excelFOS != null){
excelFOS.close();
}
if(wb != null){
wb.close();
}
} catch (IOException ex) {
ex.printStackTrace();
}
} //---- end finally
} //---- end if condition
}
I am expecting for the header to be exported. Can anyone help me with this.

Not really clear what tblData is in your provided code. But If I would have the requirement to export a JTable to Excel, then I would go by TableModel of the JTable. First write the column names to first row of the Excel sheet using TableModel.getColumnName. Then write the table data to next rows of the Excelsheet using TableModel.getValueAt.
Complete example:
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.FileOutputStream;
import javax.swing.JTable;
import javax.swing.table.TableModel;
class WriteJTableToExcel {
static void exportToExcel(JTable table, String filePath) throws Exception {
TableModel model = table.getModel();
Workbook workbook = new XSSFWorkbook();
Sheet sheet = workbook.createSheet();
Row row;
Cell cell;
// write the column headers
row = sheet.createRow(0);
for (int c = 0; c < model.getColumnCount(); c++) {
cell = row.createCell(c);
cell.setCellValue(model.getColumnName(c));
}
// write the data rows
for (int r = 0; r < model.getRowCount(); r++) {
row = sheet.createRow(r+1);
for (int c = 0; c < model.getColumnCount(); c++) {
cell = row.createCell(c);
Object value = model.getValueAt(r, c);
if (value instanceof String) {
cell.setCellValue((String)value);
} else if (value instanceof Double) {
cell.setCellValue((Double)value);
}
}
}
FileOutputStream out = new FileOutputStream(filePath);
workbook.write(out);
out.close();
workbook.close();
}
public static void main(String[] args) throws Exception {
Object columnNames[] = {"Name", "Amount", "Factor"};
Object rowData[][] = {
{"Bob", 12.0, 3.0},
{"Alice", 34.0, 2.5},
{"Jack", 56.0, 2.0},
{"John", 78.0, 1.5}
};
JTable table = new JTable(rowData, columnNames);
exportToExcel(table, "./Excel.xlsx");
}
}

you need to export the getTableHeader() from your jTable separately before you export your data. It is not stored together with the data, as it is in an Excel workbook.
Hope that helps :-)

Related

upload large .xlsx file in gui java

i have a large excel file containing 600.000 rows , i used XSSFWorkbook to upload the excel file at a Jtable in my GUI but it takes about 15 minutes to be done in eclipse and once i export my project to a jar file i can't do it even in the 15 minutes . Any help please ?
Here is the method , that i found in internet to upload my excel file .
void fillData(File file) {
int index = -1;
XSSFWorkbook workbook = null;
try {
try {
String f = file.getPath();
File file1 = new File(f);
OPCPackage opcPackage = OPCPackage.open(file1);
workbook = new XSSFWorkbook(opcPackage);
} catch (IOException ex) {
Logger.getLogger(ProjectApp3.class.getName()).log(Level.SEVERE, null, ex);
}
String[] strs = new String[workbook.getNumberOfSheets()];
//get all sheet names from selected workbook
for (int i = 0; i < strs.length; i++) {
strs[i] = workbook.getSheetName(i);
}
JFrame frame = new JFrame("Input Dialog");
//select sheet
String selectedsheet = (String) JOptionPane.showInputDialog(
frame, "Which worksheet you want to import ?", "Select Worksheet",
JOptionPane.QUESTION_MESSAGE, null, strs, strs[0]);
if (selectedsheet != null) {
for (int i = 0; i < strs.length; i++) {
if (workbook.getSheetName(i).equalsIgnoreCase(selectedsheet))
index = i;
}
XSSFSheet sheet = workbook.getSheetAt(index);
XSSFRow row = sheet.getRow(0);
//import headers data
headers.clear();
for (int i = 0; i < row.getLastCellNum(); i++) {
XSSFCell cell1 = row.getCell(i);
headers.add(cell1.toString());
}
//import data
data1.clear();
for (int j = 1; j < sheet.getLastRowNum() + 1; j++) {
Vector d = new Vector();
row = sheet.getRow(j);
int noofrows = row.getLastCellNum();
for (int i = 0; i < noofrows; i++) { //To handle empty excel cells
XSSFCell cell = row.getCell(i,
org.apache.poi.ss.usermodel.Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
d.add(cell.toString());
}
d.add("\n");
data1.add(d);
}
} else {
return;
}
} catch (Exception e) {
e.printStackTrace();
}
}
I think the basic problem is that you're trying to give. your Jtable all the data at startup. This is going to be deeply problematic. You may want to write a custom subclass from AbstractTableModel. See the docs for Jtable that includes this:
TableModel dataModel = new AbstractTableModel() {
public int getColumnCount() { return 10; }
public int getRowCount() { return 10;}
public Object getValueAt(int row, int col) { return new Integer(row*col); }
};
JTable table = new JTable(dataModel);
JScrollPane scrollpane = new JScrollPane(table);
You can implement those three methods based on the info that POI gives you. But do lazy loading of the data, most especially for getValueAt(). Keep the spreadsheet file open and grab the data only when the user scrolls to view it.

Apache POI Update Excel File After Adding Columns/Rows to JTable

New here so please be kind. I've spent a few hours trawling through posts trying to find an answer but no such luck.
I have an excel file that I import into a JTable and can then edit. Add columns, rows etc.
When I click the button to add a column or row they appear on the JTable as expected. However when I click the save button to save the file it hasn't added the new columns or rows to the Excel file.
I thought my save wasn't working correctly, but if I edit one of the two columns I already have saved in the Excel file the changes are saved to the Excel file so I am confused as to why I can edit the existing data in the file but any new rows or columns are not saved.
My export to excel is:
public void toExcel()
{
try
{
FileInputStream fsIP = new FileInputStream(new File("Recipes.xls"));
HSSFWorkbook fWorkbook = new HSSFWorkbook(fsIP);
HSSFSheet fSheet = fWorkbook.getSheet("RECIPES");
HSSFFont sheetTitleFont = fWorkbook.createFont();
HSSFCellStyle cellStyle = fWorkbook.createCellStyle();
sheetTitleFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
TableColumnModel tcm = tables.getColumnModel();
HSSFRow fRow = fSheet.createRow((short) 0);
for(int j = 0; j < tcm.getColumnCount(); j++)
{
HSSFCell cell = fRow.createCell((int) j);
cell.setCellValue(tcm.getColumn(j).getHeaderValue().toString());
}
for (int i = 0, row = 1; i < models.getRowCount(); i++, row++)
{
HSSFRow fRow1 = fSheet.createRow((short) row);
for (int j = 0; j < models.getColumnCount(); j++)
{
HSSFCell cell = fRow1.createCell((int) j);
cell.setCellValue(models.getValueAt(i, j).toString());
cell.setCellStyle(cellStyle);
}
}
FileOutputStream output_file = new FileOutputStream(new File("Recipes.xls"));
BufferedOutputStream bos = new BufferedOutputStream(output_file);
fWorkbook.write(output_file);
fWorkbook.close();
bos.close();
output_file.close();
}
catch(Exception e)
{
}
JOptionPane.showMessageDialog(
null, "Changes Saved",
"Confirmation",
JOptionPane.INFORMATION_MESSAGE);
}
My method for adding a column is as follows:
public void addNewRecipe()
{
models.addColumn(JOptionPane.showInputDialog("Enter A Description for Recipe"));
}
Thanks.
EDIT
Here is code for calling toExcel
saveButton.addActionListener(new ActionListener()
{
#Override public void actionPerformed(ActionEvent arg0)
{
{
models = new DefaultTableModel(datas, headers);
tableWidth = models.getColumnCount() * 150;
tableHeight = models.getRowCount() * 50;
tables.setPreferredSize(new Dimension( tableWidth, tableHeight));
tables.setModel(models);
tables.setRowHeight(50);
toExcel();
}
}
});

Retrieving selective sheet data from "large Excel 2003" file using java [duplicate]

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:
for(i=0; i <rows; i++)
//read [i,col1] ,[i,col2], [i,col3]
for(i=0; i<rows; i++)
//write [i,col1], [i,col2], [i,col3]
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) {
ioe.printStackTrace();
}
On the documentation page you also have examples of how to write to excel files.
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();
First add all these jar files in your project class path:
poi-scratchpad-3.7-20101029
poi-3.2-FINAL-20081019
poi-3.7-20101029
poi-examples-3.7-20101029
poi-ooxml-3.7-20101029
poi-ooxml-schemas-3.7-20101029
xmlbeans-2.3.0
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[])
Map<String, Object[]> data = new TreeMap<String, Object[]>();
data.put("1", new Object[]{"ID", "NAME", "LASTNAME"});
data.put("2", new Object[]{1, "Amit", "Shukla"});
data.put("3", new Object[]{2, "Lokesh", "Gupta"});
data.put("4", new Object[]{3, "John", "Adwards"});
data.put("5", new Object[]{4, "Brian", "Schultz"});
//Iterate over data and write to sheet
Set<String> 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
Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext())
{
Row row = rowIterator.next();
//For each row, iterate through all the columns
Iterator<Cell> cellIterator = 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.
There is a new easy and very cool tool (10x to Kfir): xcelite
Write:
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<User> writer = sheet.getBeanWriter(User.class);
List<User> users = new ArrayList<User>();
// ...fill up users
writer.write(users);
xcelite.write(new File("users_doc.xlsx"));
Read:
Xcelite xcelite = new Xcelite(new File("users_doc.xlsx"));
XceliteSheet sheet = xcelite.getSheet("users");
SheetReader<User> reader = sheet.getBeanReader(User.class);
Collection<User> 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
String path="C:\\Book2.xlsx";
try {
File f = new File( path );
Workbook wb = WorkbookFactory.create(f);
Sheet mySheet = wb.getSheetAt(0);
Iterator<Row> rowIter = mySheet.rowIterator();
for ( Iterator<Row> rowIterator = mySheet.rowIterator() ;rowIterator.hasNext(); )
{
for ( Iterator<Cell> cellIterator = ((Row)rowIterator.next()).cellIterator() ; cellIterator.hasNext() ; )
{
System.out.println ( ( (Cell)cellIterator.next() ).toString() );
}
System.out.println( " **************************************************************** ");
}
} catch ( Exception e )
{
System.out.println( "exception" );
e.printStackTrace();
}
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
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<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
Iterator<Cell> cellIterator = 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 <= 10 || i <= rows; i++) {
row = sheet.getRow(i);
if(row != null) {
tmp = sheet.getRow(i).getPhysicalNumberOfCells();
if(tmp >= cols) cols = tmp;else{rows++;cblacks++;}
}
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) {
ioe.printStackTrace();}
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<rownumber; i++ )
{
row = sheet.getRow(i);
int colnumber = row.getLastCellNum();
for (int j=0; j<colnumber; j++ )
{
cell = row.getCell(j);
System.out.println(cell.getStringCellValue());
}
}
}
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<Row> 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<Bean>()
.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)
{System.out.println(e.getMessage());
}
}
//*************************************************************
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){return ""; }
}
//*************************************************************
public static int getLastRow(){
return sh.getLastRowNum();
}
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);
Iterator<Row> itr = sheet.iterator();
// Iterating over Excel file in Java
while (itr.hasNext()) {
Row row = itr.next();
// Iterating over each column of Excel file
Iterator<Cell> cellIterator = 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<String, Object[]> newData = new HashMap<String, Object[]>();
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<String> 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();
}
}
}
Please use Apache POI libs and try this.
try
{
FileInputStream x = new FileInputStream(new File("/Users/rajesh/Documents/rajesh.xls"));
//Create Workbook instance holding reference to .xlsx file
Workbook workbook = new HSSFWorkbook(x);
//Get first/desired sheet from the workbook
Sheet sheet = workbook.getSheetAt(0);
//Iterate through each rows one by one
for (Iterator<Row> iterator = sheet.iterator(); iterator.hasNext();) {
Row row = (Row) iterator.next();
for (Iterator<Cell> iterator2 = row.iterator(); iterator2
.hasNext();) {
Cell cell = (Cell) iterator2.next();
System.out.println(cell.getStringCellValue());
}
}
x.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
When using the apache poi 4.1.2. The celltype changes a bit. Below is an example
try {
File excel = new File("/home/name/Downloads/bb.xlsx");
FileInputStream fis = new FileInputStream(excel);
XSSFWorkbook book = new XSSFWorkbook(fis);
XSSFSheet sheet = book.getSheetAt(0);
Iterator<Row> itr = sheet.iterator();
// Iterating over Excel file in Java
while (itr.hasNext()) {
Row row = itr.next();
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
switch (cell.getCellType()) {
case STRING:
System.out.print(cell.getStringCellValue() + "\t");
break;
case NUMERIC:
System.out.print(cell.getNumericCellValue() + "\t");
break;
case BOOLEAN:
System.out.print(cell.getBooleanCellValue() + "\t");
break;
default:
}
}
System.out.println("");}
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
If you go for third party library option, try using Aspose.Cells API that enables Java Applications to create (read/write) and manage Excel spreadsheets efficiently without requiring Microsoft Excel.
e.g
Sample code:
1.
//Load sample workbook
Workbook wb = new Workbook(dirPath + "sample.xlsx");
//Access first worksheet
Worksheet ws = wb.getWorksheets().get(0);
//Access cells iterator
Iterator itrat = ws.getCells().iterator();
//Print cells name in iterator
while(itrat.hasNext())
{
Cell cell = (Cell)itrat.next();
System.out.println(cell.getName() + ": " + cell.getStringValue().trim());
}
Workbook book = new Workbook("sample.xlsx");
Worksheet sheet = book.getWorksheets().get(0);
Range range = sheet.getCells().getMaxDisplayRange();//You may also create your desired range (in the worksheet) using, e.g sheet.getCells().createRange("A1", "J11");
Iterator rangeIterator = range.iterator();
while(rangeIterator.hasNext())
{
Cell cell = (Cell)rangeIterator.next();
//your code goes here.
}
Hope, this helps a bit.
PS. I am working as Support developer/ Evangelist at Aspose.
If you need to do anything more with office documents in Java, go for POI as mentioned.
For simple reading/writing an excel document like you requested, you can use the CSV format (also as mentioned):
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
public class CsvWriter {
public static void main(String args[]) throws IOException {
String fileName = "test.xls";
PrintWriter out = new PrintWriter(new FileWriter(fileName));
out.println("a,b,c,d");
out.println("e,f,g,h");
out.println("i,j,k,l");
out.close();
BufferedReader in = new BufferedReader(new FileReader(fileName));
String line = null;
while ((line = in.readLine()) != null) {
Scanner scanner = new Scanner(line);
String sep = "";
while (scanner.hasNext()) {
System.out.println(sep + scanner.next());
sep = ",";
}
}
in.close();
}
}
This will write a JTable to a tab separated file that can be easily imported into Excel. This works.
If you save an Excel worksheet as an XML document you could also build the XML file for EXCEL with code. I have done this with word so you do not have to use third-party packages.
This could code have the JTable taken out and then just write a tab separated to any text file and then import into Excel. I hope this helps.
Code:
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JTable;
import javax.swing.table.TableModel;
public class excel {
String columnNames[] = { "Column 1", "Column 2", "Column 3" };
// Create some data
String dataValues[][] =
{
{ "12", "234", "67" },
{ "-123", "43", "853" },
{ "93", "89.2", "109" },
{ "279", "9033", "3092" }
};
JTable table;
excel() {
table = new JTable( dataValues, columnNames );
}
public void toExcel(JTable table, File file){
try{
TableModel model = table.getModel();
FileWriter excel = new FileWriter(file);
for(int i = 0; i < model.getColumnCount(); i++){
excel.write(model.getColumnName(i) + "\t");
}
excel.write("\n");
for(int i=0; i< model.getRowCount(); i++) {
for(int j=0; j < model.getColumnCount(); j++) {
excel.write(model.getValueAt(i,j).toString()+"\t");
}
excel.write("\n");
}
excel.close();
}catch(IOException e){ System.out.println(e); }
}
public static void main(String[] o) {
excel cv = new excel();
cv.toExcel(cv.table,new File("C:\\Users\\itpr13266\\Desktop\\cs.tbv"));
}
}

FileOutputStream (Apachhe POI) taking too long time to save

When I am edit a .xlsx file using Apache poi, its taking too long to save. The .xlsx file contains, formulas formatting and freeze pane. I am using the following code,
try {
FileInputStream file = new FileInputStream(new File(path));
XSSFWorkbook fWorkbook = new XSSFWorkbook(file);
XSSFSheet fSheet = fWorkbook.getSheetAt(0);
for(int i = 0; i < jTable1.getRowCount(); i++){
if(jTable1.getModel().getValueAt(i, index1).equals("1")){
XSSFCell cell = fSheet.getRow(i+1).getCell(index1);
cell.setCellType(XSSFCell.CELL_TYPE_NUMERIC);
cell.setCellValue(new Double(1));
XSSFCellStyle cs = fWorkbook.createCellStyle();
cs.setDataFormat(fWorkbook.getCreationHelper().createDataFormat().getFormat("dd/MMMM/yyyy"));
cell =fSheet.getRow(i+1).getCell(index2);
cell.setCellValue(new Date());
cell.setCellStyle(cs);
}
}
file.close();
FileOutputStream fileOutputStream = new FileOutputStream(path);
fWorkbook.write(fileOutputStream);
fileOutputStream.close();
JOptionPane.showMessageDialog(this, "Data saved successfully.");
parent.removeContent();
}catch(Exception e){
e.printStackTrace();
}
Edit 1:
The excel file: http://ge.tt/5orGWSJ2/v/0?c
Loading Data into JTable from Excel:
try {
FileInputStream file1 = new FileInputStream(new File("c:\\sample.xlsx"));
XSSFWorkbook workbook = new XSSFWorkbook(file1);
XSSFSheet sheet = workbook.getSheetAt(0);
int rowc=sheet.getLastRowNum()+1;
int colc=sheet.getRow(0).getLastCellNum();
Object heading[] = new Object[colc+1];
XSSFRow row1 = sheet.getRow(0);
for(int i=0, column =0; i < colc; i++){
if(i == 1){
heading[column++] = "";
}
heading[column++] = cellToString(row1.getCell(i));
}
Object [][]j=new Object[rowc-1][colc+1];
for (int i = 1; i < rowc; i++) {
row1 = sheet.getRow(i);
for (int jj = 0, column = 0; jj < colc; jj++) {
if(column == 1){
j[i-1][column++] = new Boolean(false);
j[i-1][column] = cellToString(row1.getCell(jj));
}
else{
j[i-1][column]=cellToString(row1.getCell(jj));
}
column++;
}
}
jTable1.setModel(new DefaultTableModel(j, heading){
public Class getColumnClass(int columnIndex) {
if(columnIndex == 0){
return java.lang.Integer.class;
}
else if(columnIndex == 1){
return java.lang.Boolean.class;
}
else{
return java.lang.Object.class;
}
}
});
jTable1.getColumnModel().getColumn(1).setMaxWidth(60);
jTable1.setAutoResizeMode( JTable.AUTO_RESIZE_OFF );
jTable1.getTableHeader().setReorderingAllowed(false);
} catch (IOException ex) {
JOptionPane.showMessageDialog(BarcodePrint.this, ex);
}
Writing data into excel after editing column BarcodePrint:
try {
FileInputStream file = new FileInputStream(new File("c:\\sample.xlsx"));
XSSFWorkbook fWorkbook = new XSSFWorkbook(file);
XSSFCellStyle cs = fWorkbook.createCellStyle();
cs.setDataFormat(fWorkbook.getCreationHelper().createDataFormat().getFormat("dd/MMMM/yyyy"));
Date currentdate = new Date();
XSSFSheet fsheet = fWorkbook.getSheetAt(0);
Double barcodeprintstatus = new Double(1);
int newindex = 24;
int printdate = 26;
int uniqueid = 27;
for(int i = 0; i < jTable1.getModel().getRowCount(); i++){
if(jTable1.getModel().getValueAt(i, newindex).equals("1")){
for(int k=1; k < fsheet.getPhysicalNumberOfRows(); k++){
XSSFCell cell = fsheet.getRow(k).getCell(uniqueid-1);
String uid = cell.getRawValue();
if(jTable1.getModel().getValueAt(i, uniqueid).toString().equals(uid)){
cell = (fsheet.getRow(i+1)).getCell(newindex-1);
cell.setCellType(XSSFCell.CELL_TYPE_NUMERIC);
cell.setCellValue(barcodeprintstatus);
cell = fsheet.getRow(i+1).getCell(printdate-1);
cell.setCellValue(currentdate);
cell.setCellStyle(cs);
}
}
}
}
file.close();
FileOutputStream fileOutputStream = new FileOutputStream("c:\\sample.xlsx");
fWorkbook.write(fileOutputStream); // this is taking so much of time. Approximately 1 min.
fileOutputStream.close();
}catch(Exception e){
e.printStackTrace();
}
I am unable to solve this problem. fWorkbook.write(fileOutputStream); is taking so much of time as I mentioned above. Please help. Is there any other way to save the excel file? Or can I write data partially for a single column rather than the hole workbook?
Try to improve the code.
You call fSheet.getRow(i+1) twice. Try to introduce a variable and reuse the row rather than obtain it.
cell.setCellValue(new Double(1));
Create the 1 double once before the for loop and reuse it.
XSSFCellStyle cs = fWorkbook.createCellStyle();
cs.setDataFormat(fWorkbook.getCreationHelper().createDataFormat().getFormat("dd/MMMM/yyyy"));
Move the cell style creation and initializing out of the for loop. Create it before the loop and reuse.
cell.setCellValue(new Date());
Introduce a Date variable and create the Date just once. Again before the for loop.
Add a BufferedOutputStream around the FileOutputStream.

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:
for(i=0; i <rows; i++)
//read [i,col1] ,[i,col2], [i,col3]
for(i=0; i<rows; i++)
//write [i,col1], [i,col2], [i,col3]
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) {
ioe.printStackTrace();
}
On the documentation page you also have examples of how to write to excel files.
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();
First add all these jar files in your project class path:
poi-scratchpad-3.7-20101029
poi-3.2-FINAL-20081019
poi-3.7-20101029
poi-examples-3.7-20101029
poi-ooxml-3.7-20101029
poi-ooxml-schemas-3.7-20101029
xmlbeans-2.3.0
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[])
Map<String, Object[]> data = new TreeMap<String, Object[]>();
data.put("1", new Object[]{"ID", "NAME", "LASTNAME"});
data.put("2", new Object[]{1, "Amit", "Shukla"});
data.put("3", new Object[]{2, "Lokesh", "Gupta"});
data.put("4", new Object[]{3, "John", "Adwards"});
data.put("5", new Object[]{4, "Brian", "Schultz"});
//Iterate over data and write to sheet
Set<String> 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
Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext())
{
Row row = rowIterator.next();
//For each row, iterate through all the columns
Iterator<Cell> cellIterator = 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.
There is a new easy and very cool tool (10x to Kfir): xcelite
Write:
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<User> writer = sheet.getBeanWriter(User.class);
List<User> users = new ArrayList<User>();
// ...fill up users
writer.write(users);
xcelite.write(new File("users_doc.xlsx"));
Read:
Xcelite xcelite = new Xcelite(new File("users_doc.xlsx"));
XceliteSheet sheet = xcelite.getSheet("users");
SheetReader<User> reader = sheet.getBeanReader(User.class);
Collection<User> 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
String path="C:\\Book2.xlsx";
try {
File f = new File( path );
Workbook wb = WorkbookFactory.create(f);
Sheet mySheet = wb.getSheetAt(0);
Iterator<Row> rowIter = mySheet.rowIterator();
for ( Iterator<Row> rowIterator = mySheet.rowIterator() ;rowIterator.hasNext(); )
{
for ( Iterator<Cell> cellIterator = ((Row)rowIterator.next()).cellIterator() ; cellIterator.hasNext() ; )
{
System.out.println ( ( (Cell)cellIterator.next() ).toString() );
}
System.out.println( " **************************************************************** ");
}
} catch ( Exception e )
{
System.out.println( "exception" );
e.printStackTrace();
}
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
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<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
Iterator<Cell> cellIterator = 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 <= 10 || i <= rows; i++) {
row = sheet.getRow(i);
if(row != null) {
tmp = sheet.getRow(i).getPhysicalNumberOfCells();
if(tmp >= cols) cols = tmp;else{rows++;cblacks++;}
}
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) {
ioe.printStackTrace();}
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<rownumber; i++ )
{
row = sheet.getRow(i);
int colnumber = row.getLastCellNum();
for (int j=0; j<colnumber; j++ )
{
cell = row.getCell(j);
System.out.println(cell.getStringCellValue());
}
}
}
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<Row> 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<Bean>()
.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)
{System.out.println(e.getMessage());
}
}
//*************************************************************
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){return ""; }
}
//*************************************************************
public static int getLastRow(){
return sh.getLastRowNum();
}
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);
Iterator<Row> itr = sheet.iterator();
// Iterating over Excel file in Java
while (itr.hasNext()) {
Row row = itr.next();
// Iterating over each column of Excel file
Iterator<Cell> cellIterator = 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<String, Object[]> newData = new HashMap<String, Object[]>();
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<String> 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();
}
}
}
Please use Apache POI libs and try this.
try
{
FileInputStream x = new FileInputStream(new File("/Users/rajesh/Documents/rajesh.xls"));
//Create Workbook instance holding reference to .xlsx file
Workbook workbook = new HSSFWorkbook(x);
//Get first/desired sheet from the workbook
Sheet sheet = workbook.getSheetAt(0);
//Iterate through each rows one by one
for (Iterator<Row> iterator = sheet.iterator(); iterator.hasNext();) {
Row row = (Row) iterator.next();
for (Iterator<Cell> iterator2 = row.iterator(); iterator2
.hasNext();) {
Cell cell = (Cell) iterator2.next();
System.out.println(cell.getStringCellValue());
}
}
x.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
When using the apache poi 4.1.2. The celltype changes a bit. Below is an example
try {
File excel = new File("/home/name/Downloads/bb.xlsx");
FileInputStream fis = new FileInputStream(excel);
XSSFWorkbook book = new XSSFWorkbook(fis);
XSSFSheet sheet = book.getSheetAt(0);
Iterator<Row> itr = sheet.iterator();
// Iterating over Excel file in Java
while (itr.hasNext()) {
Row row = itr.next();
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
switch (cell.getCellType()) {
case STRING:
System.out.print(cell.getStringCellValue() + "\t");
break;
case NUMERIC:
System.out.print(cell.getNumericCellValue() + "\t");
break;
case BOOLEAN:
System.out.print(cell.getBooleanCellValue() + "\t");
break;
default:
}
}
System.out.println("");}
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
If you go for third party library option, try using Aspose.Cells API that enables Java Applications to create (read/write) and manage Excel spreadsheets efficiently without requiring Microsoft Excel.
e.g
Sample code:
1.
//Load sample workbook
Workbook wb = new Workbook(dirPath + "sample.xlsx");
//Access first worksheet
Worksheet ws = wb.getWorksheets().get(0);
//Access cells iterator
Iterator itrat = ws.getCells().iterator();
//Print cells name in iterator
while(itrat.hasNext())
{
Cell cell = (Cell)itrat.next();
System.out.println(cell.getName() + ": " + cell.getStringValue().trim());
}
Workbook book = new Workbook("sample.xlsx");
Worksheet sheet = book.getWorksheets().get(0);
Range range = sheet.getCells().getMaxDisplayRange();//You may also create your desired range (in the worksheet) using, e.g sheet.getCells().createRange("A1", "J11");
Iterator rangeIterator = range.iterator();
while(rangeIterator.hasNext())
{
Cell cell = (Cell)rangeIterator.next();
//your code goes here.
}
Hope, this helps a bit.
PS. I am working as Support developer/ Evangelist at Aspose.
If you need to do anything more with office documents in Java, go for POI as mentioned.
For simple reading/writing an excel document like you requested, you can use the CSV format (also as mentioned):
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
public class CsvWriter {
public static void main(String args[]) throws IOException {
String fileName = "test.xls";
PrintWriter out = new PrintWriter(new FileWriter(fileName));
out.println("a,b,c,d");
out.println("e,f,g,h");
out.println("i,j,k,l");
out.close();
BufferedReader in = new BufferedReader(new FileReader(fileName));
String line = null;
while ((line = in.readLine()) != null) {
Scanner scanner = new Scanner(line);
String sep = "";
while (scanner.hasNext()) {
System.out.println(sep + scanner.next());
sep = ",";
}
}
in.close();
}
}
This will write a JTable to a tab separated file that can be easily imported into Excel. This works.
If you save an Excel worksheet as an XML document you could also build the XML file for EXCEL with code. I have done this with word so you do not have to use third-party packages.
This could code have the JTable taken out and then just write a tab separated to any text file and then import into Excel. I hope this helps.
Code:
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JTable;
import javax.swing.table.TableModel;
public class excel {
String columnNames[] = { "Column 1", "Column 2", "Column 3" };
// Create some data
String dataValues[][] =
{
{ "12", "234", "67" },
{ "-123", "43", "853" },
{ "93", "89.2", "109" },
{ "279", "9033", "3092" }
};
JTable table;
excel() {
table = new JTable( dataValues, columnNames );
}
public void toExcel(JTable table, File file){
try{
TableModel model = table.getModel();
FileWriter excel = new FileWriter(file);
for(int i = 0; i < model.getColumnCount(); i++){
excel.write(model.getColumnName(i) + "\t");
}
excel.write("\n");
for(int i=0; i< model.getRowCount(); i++) {
for(int j=0; j < model.getColumnCount(); j++) {
excel.write(model.getValueAt(i,j).toString()+"\t");
}
excel.write("\n");
}
excel.close();
}catch(IOException e){ System.out.println(e); }
}
public static void main(String[] o) {
excel cv = new excel();
cv.toExcel(cv.table,new File("C:\\Users\\itpr13266\\Desktop\\cs.tbv"));
}
}

Categories