Base class With Multiple window Handle

package com.seleniumpractice;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;

public class Base {
public static WebDriver  driver;
public static WebElement webele;
public static String url="https://www.zoho.com/signup.html";
public static void config() {
System.setProperty("webdriver.chrome.driver","C:\\Users\\admin\\Desktop\\Selenium_software\\chromedriver.exe\\");
driver=new ChromeDriver();
driver.get(url);
driver.manage().window().maximize();
driver.manage().timeouts().implicitlyWait(10,TimeUnit.SECONDS);
}
public static void closeBrowser() {
driver.close();
}

public static void quitBrowser() {
driver.quit();
     }
public static String getTitle() {
return driver.getTitle();
}

public static String getTextStr() {
return webele.getText();

}

public static void switchTo(String str) {
driver.switchTo().window(str);
}

public static void testCasePassed() {
System.out.println("***********Test case Passed***********");
}

public static void frameSize() {
int size=driver.findElements(By.tagName("iframe")).size();
System.out.println("Size of frame..."+size);
}

}
 public static void compareText(String actualStr,String expStr) {
   if(actualStr.contentEquals(expStr)) {
   Base.testcasePased();
   }
   else {
   Base.testFiledPased();
   }
   }
 

===================================================================

package com.multiptest;

import java.util.Iterator;
import java.util.Set;

import org.openqa.selenium.By;

public class CitibanmkTest extends Base{

public static void main(String[] args) {
Base.config();
String parentwind=driver.getWindowHandle();
System.out.println("********Parent Wind*****"+ driver.getTitle());
driver.findElement(By.xpath("//a[@id='loginId']/img")).click();
Set<String> set=driver.getWindowHandles();
Iterator<String> itr=set.iterator();
while(itr.hasNext()) {
String childWindow=itr.next();
if(!parentwind.equals(childWindow)) {
//driver.switchTo().window(childWindow);
Base.switchWindow(childWindow);
String textActual=driver.findElement(By.xpath("//h1[contains(text(),'Welcome to Citibank Online')]")).getText();
String expText="Welcome to Citibank Online";
Base.compareText(textActual, expText);
/*
if(textActual.equals(expText)) {
Base.testcasePased();
}
else {
Base.testFiledPased();
}
*/

}

}
//driver.switchTo().window(parentwind);
Base.switchWindow(parentwind);
String expTitle=driver.getTitle();
System.out.println("*****expTitle******"+expTitle);
String actualTitle="Citi India - Credit Cards, Personal & Home Loans, Investment, Wealth Management & Banking";
System.out.println("********** actualTitle ********" + actualTitle);
/*
if(expTitle.equals(actualTitle)) {
Base.testcasePased();
}
else {
Base.testFiledPased();
}
*/
Base.compareText(actualTitle, expTitle);
Base.quitbrowser();
Base.executionSuucess();


}

}