Java: Difficulty with ConcurrentModificationException When Modifying List in a Stream Operation
I can't seem to get I'm prototyping a solution and I'm currently working on a feature that processes a list of user objects using Java Streams, but I'm encountering a `ConcurrentModificationException` when trying to remove elements from the list while performing a filter operation... My code looks like this: ```java import java.util.ArrayList; import java.util.List; public class UserProcessor { public static void main(String[] args) { List<User> users = new ArrayList<>(); users.add(new User("Alice", 30)); users.add(new User("Bob", 25)); users.add(new User("Charlie", 35)); users.stream() .filter(user -> user.getAge() > 30) .forEach(user -> { users.remove(user); // ConcurrentModificationException thrown here }); } } class User { private String name; private int age; public User(String name, int age) { this.name = name; this.age = age; } public int getAge() { return age; } } ``` When I run this code, I receive the following error: ``` Exception in thread "main" java.util.ConcurrentModificationException ``` I've tried changing the approach to collect the filtered users into a separate list first and then removing them, but that seems inefficient and defeats the purpose of using streams. Additionally, I considered using an `Iterator` for safe removal, but I want to stick with a functional style if possible. Is there a best practice to handle this situation without resorting to traditional loops and iterators? Any guidance on how to resolve this would be greatly appreciated! I'm working with Java in a Docker container on Ubuntu 20.04. Is there a better approach? Any feedback is welcome! I'm coming from a different tech stack and learning Java. Thanks in advance! The project is a mobile app built with Java. Any feedback is welcome! This is part of a larger mobile app I'm building. What's the best practice here?