How to get hidden webelements text in Selenium Webdriver using Java

 import java.util.List;  
 import java.util.concurrent.TimeUnit;  
 import org.openqa.selenium.By;  
 import org.openqa.selenium.WebDriver;  
 import org.openqa.selenium.WebElement;  
 import org.openqa.selenium.firefox.FirefoxDriver;  
 public class HiddenElementstext {  
   public static void main(String[] args) throws InterruptedException {  
     // create objects and variables instantiation      
     WebDriver driver = new FirefoxDriver();  
     // maximize the browser window       
     driver.manage().window().maximize();  
     // launch the firefox browser and open the application url  
     driver.get("www.yahoo.com");  
     //Set timeout      
     driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);  
     //Get input tag and store in List variable name is number_of_hiddenElements  
     List<WebElement> number_of_hiddenElements = driver.findElements(By.tagName("input"));  
     //Print total number of Input tag   
     System.out.println(number_of_hiddenElements.size());  
     for (int i = 0; i < number_of_hiddenElements.size(); i++) {  
       // Print all hidden elements text  
       if (number_of_hiddenElements.get(i).getAttribute("type").trim().equalsIgnoreCase("hidden")) {  
         //Check empty text  
         if (!(number_of_hiddenElements.get(i).getAttribute("value").trim().isEmpty())) {  
           //Print hidden Element texts  
           System.out.println("Hidden Element text = " + i + " " + number_of_hiddenElements.get(i).getAttribute("value").trim());  
         }  
       }  
     }  
     // quit Firefox browser  
     driver.quit();  
   }  
 }