How to get hidden webelements text in Selenium Webdriver using Java

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();
   }
 }