Selenium - How to skip the record from the Set after the its first occurrence

Kaustubh :

I have an application view, where there are list of items. There are say 10 pages with 200 records, 20 records per page. I wish to have the unqiue user count assigned. From the below code I'am able to get the unique records per page. But I wish to get unique user entry throughout the records. So for example while execution if user "Jack" is found, so if the same user is found in later pages I want it to get skipped. Thanks in advance!

Script:

List<WebElement> efirstpagecount = driver.findElements(By.xpath("//*[@id='usersList']/tbody/tr/td[3]"));
Set<String> uniqueUsers = efirstpagecount.stream().map(WebElement::getText).map(String::trim).distinct().collect(Collectors.toSet());   
System.out.println("First page count: "+uniqueUsers.size());

Andrei Suvorkov :

You can merge your sets like this:

set1.addAll(set2);

It will add distinct all elements from set2 to a set1. The code sample:

List<WebElement> efirstpagecount = driver.findElements(By.xpath("//*[@id='usersList']/tbody/tr/td[3]"));
Set<String> uniqueUsers = efirstpagecount.stream().map(WebElement::getText).map(String::trim).distinct().collect(Collectors.toSet());   
System.out.println("First page count: "+uniqueUsers.size());

List<WebElement> esecondpagecount = driver.findElements(By.xpath("//*[@id='usersList']/tbody/tr/td[3]"));
Set<String> uniqueUsers2 = esecondpagecount.stream().map(WebElement::getText).map(String::trim).distinct().collect(Collectors.toSet());
uniqueUsers.addAll(uniqueUsers2); // merge two sets
System.out.println("First and second page count: "+uniqueUsers.size());

or this:

Set<String> allUsers = new HashSet();
while(true){
  List<WebElement> users = driver.findElements(By.xpath("xpath"));
  allUsers.addAll(users.stream().map(WebElement::getText).map(String::trim).distinct().collect(Collectors.toSet()));
  // move to next page if exists, else break loop
}
System.out.println("All pages count: " + allUsers.size());

PS performance of addAll() is O(N):

// implementation of addAll() method
public boolean addAll(Collection<? extends E> c) {
    boolean modified = false;
    for (E e : c)
        if (add(e))
            modified = true;
    return modified;
}