How do I find a specific element in a list of objects?

I parsed all the JSON from /posts at JSONPlaceholder into a list of objects. But I'm having trouble trying to find a specific object. With all the examples on searching lists online I can't seem to be able to get it.

I ask the user to input a number into int values checkId and checkUserId and then compare it. If it matches it should print out the title.

Iterator < Post > iter = posts.iterator();
while (iter.hasNext()) {
  if (Objects.equals(iter.next().getUserId(), checkUserId)) {
    System.out.println("found UserId");

    if (Objects.equals(iter.next().getId(), checkId)) {
      System.out.println("found Id");
      //prints the title of object
    }
  }
}

I then tried to use a stream:

List<Post> result = posts.stream()
        .filter(title -> checkId.equals(getId()))
        .findAny()
        .orElse(null);

All the code I cloned it from Java 11 HttpClient Tutorial by Dan Vega.

Your first attempt does not work because you are advancing the iterator twice on each iteration by calling next. Instead, store the result of Iterator#next and use it.

Iterator<Post> iter = posts.iterator();
 while(iter.hasNext()){
        Post post = iter.next();
        if(Objects.equals(post.getUserId(), checkUserId)) {
            System.out.println("found UserId");
            System.out.println(post.getTitle());
        }
    }

With streams:

List<String> titles = posts.stream().filter(post-> checkId.equals(post.getId()))
                        .map(Post::getTitle).collect(Collectors.toList());
titles.forEach(System.out::println);