Hi Mohan, you can use following code snippet to read test data from an excel sheet and use it to test facebook login page:
public class ReadWriteExcel
{
WebDriver driver;
WebDriverWait wait;
HSSFWorkbook workbook;
HSSFSheet sheet;
HSSFCell cell;
public void ReadData() throws IOException {
System.setProperty("webdriver.gecko.driver", "C:\\Users\\geckodriver.exe"); 
driver = new FirefoxDriver(); 
driver.get("http://www.facebook.com/"); 
driver.manage().window().maximize(); 
wait = new WebDriverWait(driver,30); 
driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS); 
// Import excel sheet. 
File src=new File("C:\\Users\\Admin\\Desktop\\TestData.xls"); 
// Load the file. 
FileInputStream finput = new FileInputStream(src); 
// Load the workbook. 
workbook = new HSSFWorkbook(finput); 
// Load the sheet in which data is stored. 
sheet= workbook.getSheetAt(0); 
for(int i=1; i<=sheet.getLastRowNum(); i++) { 
// Import data for Email. 
cell = sheet.getRow(i).getCell(1); 
cell.setCellType(Cell.CELL_TYPE_STRING); 
driver.findElement(By.id("email")).sendKeys(cell.getStringCellValue()); 
// Import data for password. 
cell = sheet.getRow(i).getCell(2); 
cell.setCellType(Cell.CELL_TYPE_STRING); 
driver.findElement(By.id("pass")).sendKeys(cell.getStringCellValue()); 
} 
} 
}