Write Excel Files in Java using Apache POI






Apache POI is the api to create and modify Microsoft office files.
But here i will discuss about how to create and modify excel sheets(spreadsheet).
HSSF is used to create .xls file and XSSF is used to create .xlsx file.

Below jar files required to Create excel sheets.

1. ooxml-schemas-1.3.jar
2. poi-3.14.jar
3. poi-ooxml-3.14.jar
4. xmlbeans-2.6.0.jar

package com.javaant;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFFont;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;


/**
*
* @author nirmal
*/
public class WriteToExcel {

	
	static String filepath = null;
	Object[][] data = null;
	public static void main(String ar[]) {
		WriteToExcel rw = new WriteToExcel("D:\\Java_Ant_Post\\readWritexls-poi\\ReadWriteExcel\\excels\\abc.xlsx");
		rw.writeDataToExcel(filepath);
		//rw.readDataFromExcel();

	}
	public WriteToExcel(String filepath) {
		this.filepath = filepath;
	}

	public File getFile() throws FileNotFoundException {
		File here = new File(filepath);
		return new File(here.getAbsolutePath());

	}

	
	
	private static void writeToCell(int rowno, int colno, XSSFSheet sheet, String val) {
		try {
			sheet.getRow(rowno);
			XSSFRow row = sheet.getRow(rowno);
			if (row == null) {
				row = sheet.createRow(rowno);
			}
			XSSFCell cell = row.createCell(colno);
			cell.setCellValue(val);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	
	public static void writeDataToExcel(String file) {
		XSSFWorkbook wb = null;
		XSSFSheet sheet = null;
		FileOutputStream fileOut = null;
		
		
			String excelFileName = file;

			String sheetName = "Sheet1";//name of sheet

			wb = new XSSFWorkbook();
			sheet = wb.createSheet(sheetName);
			DecimalFormat df2 = new DecimalFormat(".##");
			try{

	
			
			writeToCell(0, 0, sheet,  "This is one");// row 1 column 1
			writeToCell(0, 1, sheet,  "this is two");// row 1 column 2
			writeToCell(1, 0, sheet,  "this is three");// row 2 column 1
			writeToCell(1, 1, sheet,  "this is four");// row 2 column 2
			int r = 4;
			
			System.out.println("working fine");
			fileOut = new FileOutputStream(excelFileName);
			wb.write(fileOut);

			//write this workbook to an Outputstream.
		} catch (Exception e) {
			e.printStackTrace();
		} finally {

			try {
				fileOut.flush();
				fileOut.close();
			} catch (IOException ex) {
				Logger.getLogger(WriteToExcel.class.getName()).log(Level.SEVERE, null, ex);
			}

		}
	}

	
}

Output