How to operate new single window or multiple windows in selenium webdriver using java

Some Web application allows to login to their system using Gmail, Facebook, Twitter etc account. When click on Gmail, Facebook, Twitter, its icon button, new window open with a login page. Selenium webdriver provide opportunity to handle new opened window and back to original window after completing an operation on new window. In this tutorial I will show how to operate new window.

Switch between new opened windows and original window as below:

 
// Store the current window on String variable  
 String parentwindow = driver.getWindowHandle();  

 // Do the click operation that opens new window  
 // Switch to window that's your newly opened window  

 for(String winHandle : driver.getWindowHandles()){  
   driver.switchTo().window(winHandle);  
 }  

 // code to do something on new window  

 // Close the new window, if that window no more required  
 driver.close();  

 // Switch back to original browser (parent window)  
 driver.switchTo().window(parentwindow);  

 // Continue with original browser (parent window)  

Java demo source code:

 import org.openqa.selenium.By;  
 import org.openqa.selenium.WebDriver;  
 import org.openqa.selenium.firefox.FirefoxDriver;  
 public class Operatenewwindow {  
   public static void main(String[] arg) {  
     WebDriver driver = new FirefoxDriver();  
     driver.manage().window().maximize();  
     driver.get("http://localhost:8080/idea/a/community/login");  

     // Store the current window on String variable  
     String parentwindow = driver.getWindowHandle();  
 // Do the click operation that opens new window  
     driver.findElement(By.className("icon-facebook")).click(); 
 
 // Switch to window that's your newly opened window  
     for (String winHandle : driver.getWindowHandles()) {  
       driver.switchTo().window(winHandle);  
     }  

 // code to do something on new window  
     driver.findElement(By.id("email")).sendKeys("hiro@gmail.com");  
     driver.findElement(By.id("pass")).sendKeys("123456789");  
     driver.findElement(By.id("loginbutton")).click();  

 // Close the new window, if that window no more required  
     driver.close();  

 // Switch back to original browser (parent window)  
     driver.switchTo().window(parentwindow); 

 
 // Continue with original browser (parent window)  
     driver.close();  
   }  
 }