get href value (WebDriver)

Answer 1

You have pointed your element to 'div' instead of 'a'

Try the below code

driverCE.findElement(By.xpath("//div[@id='testId']/a")).getAttribute("href");

Answer 2

If you got more than one anchor tag, the following code snippet will help to find all the links pointed by href

//find all anchor tags in the page
List<WebElement> refList = driver.findElements(By.tagName("a"));

   //iterate over web elements and use the getAttribute method to 
   //find the hypertext reference's value.

    for(WebElement we : refList) {
        System.out.println(we.getAttribute("href"));
    }